6thinternational meeting on spastic paraparesis and ataxia · 2019-10-04 · 6thinternational...
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6thInternational Meeting on Spastic Paraparesis and Ataxia
Satellite meeting of the international congress of Parkinson’s disease and
Movement Disorders – MDS September 22-26, 2019
Acropolis – Palais des Congrès et des Expositions
Nice, France
September 20-21, 2019
Held by :
The Network of Hereditary forms of SPAstic paraplegias and cerebellar ATAXias
The Ataxia Study Group
E-Rare PREPARE_Ataxia consortium
ICM Brain & Spine Institute
ORGANIZATION:
Scientific committee: Sylvia Boesch (Austria), Alexandra Durr (France), Filippo
Santorelli (Italy), Giovanni Stevanin (France), Matthis Synofzik (Germany), Chantal
Tallaksen (Norway), Bart Van de Warrenburg (Net herlands)
Local committee (ICM): Marie Biet, Alexandra Durr , Typhaine Esteves, Rania Hilab,
Hortense Hurmic, Elodie Petit, Marie-Luce Poupinel, Giovanni Stevanin
Information: [email protected]
SPONSORED BY:
Gold sponsors: ICM, SPATAX, DYNACURE, E-Rare PREPARE_Ataxia, Tom Wahlig
Foundation
Silver sponsors: ADCA vereniging (Netherlands), Association Française de l’Ataxie de
Friedreich (AFAF-France), Associazione Italiana Vivere la Paraparesi Spastica onlus
(AIViPS-Italy), Association Strümpell Lorrain (ASL-HSP-France), Connaître les
Syndromes Cérébelleux (CSC-France), EURO-HSP, National Ataxia Foundation (NAF-US),
Norwegian Association for hereditary spastic paraplegia/ataxia (Naspa -Norway),
ROCHE Diagnostics, Spastic Paraplegia Foundation (SPF -US), The Maddi Foundation
(UK)
Wi-fi CREDENTIALS:
Login: spatax
Password : spatax19
Table of Contents
Program ................................................................................... page 5
Speakers Biographies ............................................................ page 9
Abstracts ................................................................................. page 17
List of networks members (SPATAX, ASG and PREPARE) ........ page 78
List of participants to the meeting ........................................ page 86
Venue to the Get-Together event ........................................... page 94
SPATAX membership application form ................................. page 96
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Program
Thursday 19th, 14h – Friday 20th, 12h: satellite meeting of the ERARE PREPARE_Ataxia. Novotel
Hotel, Nice (restricted access to consortium members).
September, Friday 20th 2019
13:00 Welcome coffee, Registration (Opening of Poster zone)
13:45 Welcoming session by the local scientific committee
13:50 Presentation of the patient associations sponsoring the event
14:00 Plenary conferences (20’+10’ questions) Chair: Filippo Santorelli
Hélène Puccio (France) Recent insight into the cerebellar dysfunction in ARCA2 linked to COQ8A/ADCK3 mutations
Agnès Rötig (France) Impaired regulation of cytosolic iron homeostasis in Friedreich ataxia
15:00 Selected abstracts 1-3 (15’ including questions) Chair: Filippo Santorelli
[15] Claire Guissart (France) Pathogenic ATG7 variants cause recessive cerebellar ataxia [45] Eduald Balagué Cabasés (Spain) Single-intrathecal delivery of a new AAV9-mediated gene
therapy vector provides long-term safe expression of frataxin and prevents neurodegeneration in a Friedreich Ataxia mouse model.
[65] Andrea Del Bondio (Italy) A pharmacological treatment acting on calcium homeostasis improves motor ability and delays Purkinje cell loss in the ARSACS mouse model
15:45 – 16:30 Coffee break and Poster session 1f
16:30 Plenary conferences (20’+10’ questions) Chair: Frédéric Darios
Fanny Mochel (France) Metabolic forms of neurodegenerative disorders Frederic Vaz (Netherlands) Characterization of lipid metabolism in hereditary spastic
paraplegias using lipidomics
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17:30 Selected abstracts 4-5 (15’ including questions) Chair: Frédéric Darios
[54] Matthis Synofzik (Germany) Neurofilaments as blood biomarkers at the preataxic and ataxic stage of spinocerebellar ataxia type 3: a cross-species analysis in humans and mice
[75] Alexandra K. Davies (Germany / UK) Organellar proteomics to investigate the mechanism that underlies the neuronal pathology of AP-4 deficiency
18:00 Networks news (8’ each [3 slides] with 10’ final discussion) Chair: Alexis Brice
Thomas Klockgether (Germany) SCA global Matthis Synofzik (Germany) ARCA global Rebecca Schüle (Germany) TreatHSP.net and the Alliance for Treatment in HSP and PLS Alexandra Durr (France) Spatax database to setup a TransNational HSP network
18:50 End of the day (poster zone closed)
20:00 – 00:00 Get-together event (open to all registered people)
Location: MAMAC (Museum of Modern and Contemporary Art), Place Yves Klein, Nice
Including a debriefing with patient associations representatives with the scientific committee
September, Saturday 21st 2019
8:30 Welcome coffee (Opening of Poster zone)
9:00 Plenary conferences (20’+10’ questions) Chair: Sylvia Boesch
Rebecca Schüle (Germany) IP3 Receptor Degradation – A Mutational Hotspot for Hereditary Ataxia and Motor Neuron Disease
André Van Kuilenburg (Netherlands) Glutaminase deficiency, a Novel Repeat Expansion Disorder identified through Deep Phenomics and Genomics
10:00 Selected abstract 6 (15’ including questions) Chair: Sylvia Boesch
[7] Daniele Galatolo (Italy) SCA48: molecular and clinical features of novel cases in a multicentre Italian cohort
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10:15 – 11:00 Group photo, Coffee break and Poster session 2
11:00 Plenary conferences (20’+10’ questions) Chair: Antoni Matilla Dueñas
Henry Houlden (UK) A novel repeat involved in CANVAS Isabel Silveira (Portugal) A non-coding repeat insertion causes spinocerebellar ataxia type 37 Juan Bonifacino (United-States) Novel Insights into AP-4-Deficiency Syndrome
12:30 Selected abstract 7 (15’ including questions) Chair: Antoni Matilla Dueñas
[56] Almudena Avila-Fernandez (Spain) Pathogenic RCF1 repeat expansion: a frequent cause of late-onset ataxia in Spanish population
12:45 – 14:00 Lunch offered to all registered participants and Poster session 3
14:00 Plenary conferences (20’+10’ questions) Chair: Chantal Tallaksen
Gulin Oz (United-States) MRI and MRS readouts in Spinocerebellar Ataxias
14:30 Selected abstracts 8 and 9 (15’ including questions) Chair: Chantal Tallaksen
[52] Judith van Gaalen (The Netherlands) Gait-related functional MRI changes at the preclinical stage of SCA3
[72] Adam P. Vogel (Australia, Germany, Cuba, Chile) Speech and swallowing deficits are detectable at the pre-ataxic stage of Spinocerebellar Ataxia Type 2
15:00 Plenary conferences (20’+10’ questions) Chair: Matthis Synofzik
Bernard Brais (Quebec) New insights on ARSACS lead to a search for candidate compounds Frédéric Darios (France) From physiopathology to preclinical trials in SPG11
16:00 – 17:00 Coffee break and Poster session 4 (Poster votes and poster removal at 17:00)
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17:00 Round-Table Discussion on Therapy (15’ or 10’ presentation, 30’ discussion with the public)
Chair: Bart Van de Warrenburg
Invited scientist (15’ presentation)
Mimoun Azzouz (UK) Gene therapeutics for spastic paraplegia types 15 and 47 Lucy Vincent (France) Dance for ataxias and spastic paraplegias Matthis Synofzik (Germany) Exergames and physiotherapy Alexander Geurts (Netherlands) Potential effects of botulinum toxin in patients with pure HSP
Selected abstracts (10’ presentation)
[38] Roderick P.P.W.M. Maas (The Netherlands, Germany) Cerebellar transcranial direct current stimulation in spinocerebellar ataxia type 3 (SCA3-tDCS): rationale and protocol of a randomized, double-blind, sham-controlled study
[27] Andrea Martinuzzi (Italy) Safety and efficacy of Interferon γ in Friedreich ataxia: a pilot trial with clinical and paraclinical endpoints
[70] Fabricio Diniz de Lima (Brazil) A double-blind, randomized, placebo-controlled, crossover trial of botulinum toxin type A in hereditary spastic paraplegia - the SPASTOX trial
19:00 – 19:05 Closing ceremony – Prizes for the best posters on ataxias (n=1) and on spastic
paraplegias (n=1)
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Speakers Biographies (in alphabetical order)
Prof. Mimoun Azzouz obtained a Master in Neuroscience with 1st Class Honours
from the University of Marseille in 1994. In 1997 he was awarded a PhD in
Neuropharmacology at the University Louis Pasteur in Strasbourg. He then worked
as post-doctoral scientist at the Gene Therapy Center in Lausanne, Switzerland from
1997 to 2000. He was recruited in 2000 by Oxford BioMedica plc as Senior Scientist
then appointed as Director of Neurobiology in 2003. He was also a visiting scientist
at Oxford University between 2000 and 2005. In 2006, he was invited to join the
University of Sheffield and was appointed to the Chair of Translational Neuroscience. Professor Azzouz
is currently Professor at the Medical School, Deputy Head of Neurology Unit and Director of Research
& Innovation. One of his major achievements is his involvement in a gene therapy approach designed
to achieve dopamine replacement in models of Parkinson’s disease. He is currently driving 2 clinical
development programs through regulatory tox, GMP clinical manufacturing and regulatory bodies. He
is currently a member of the editorial board of various journals and member of scientific Panels/Boards
for various funding bodies. He has been recently named as Board member of the British Society for
Gene and Cell Therapy and Scientific Advisor for the Batten CLN7 gene therapy trial (Beat Batten).
Dr. Juan Bonifacino received his doctoral degree in biochemistry from the
University of Buenos Aires, Argentina, in 1981. He then moved to the NIH, where he
pursued postdoctoral studies with Dr. Richard D. Klausner. He rose through the
ranks to his current position as Associate Scientific Director for the Cell Biology and
Neurobiology Branch, NICHD, NIH. In 2008, he was appointed NIH Distinguished
Investigator. Since the early 1990s, Dr. Bonifacino's group has conducted research
on signals and adaptor proteins that mediate protein sorting to endosomes and
lysosomes. His group discovered new sorting signals and adaptor proteins, and applied this knowledge
to the elucidation of the causes of various human diseases including the Hermansky-Pudlak syndrome
type 2 and autosomal dominant polycystic liver disease. Dr. Bonifacino has served in various editorial
capacities for the journals Developmental Cell, Molecular Cell, Molecular Biology of the Cell, Journal of
Cell Biology, Journal of Biological Chemistry and Traffic. He is also the co-editor of the books Current
Protocols in Cell Biology and Short Protocols in Cell Biology. He served as a member of the Council of
the American Society for Cell Biology, and chaired various scientific conferences. He has delivered the
Alex Novikoff, Leonardo Satz, G. Burroughs Mider, Hughlings Jackson and Peter Maloney lectures, and
is an Honorary Professor of Biological Chemistry at the University of Buenos Aires. He was appointed
Fellow of the American Society for Cell Biology. His lab has trained over 70 postdoctoral fellows and
students, most of whom have pursued careers in academic research.
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Bernard Brais, MD, PhD is a neurologist, Professor of Neurology and Genetics at McGill University and co-director of the Rare Neurological Diseases group of the Montreal Neurological Institute. His research largely focuses on the genetic basis of rare neuromuscular disorders with founder effects in Quebec, with an increasing focus on disorders with ataxic manifestations such as Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS). Since 2007, he has headed a collaborative international team of researchers on ARSACS. His laboratory has characterized sacs Knock Out and Knock In transgenic mice models that recapitulates many of the
clinical manifestations of ARSACS. His group was the first to describe the neurofilament disorganization in ARSACS neurons. His KO sacsin fibroblast model is now extensively used for high throughput screening of candidate drugs. He is a principal investigator of the PREPARE project.
Dr. Frédéric Darios’ research is focused on the regulation of intracellular
organelle functions, with a special interest on the consequences of their
dysfunction in neurodegenerative disorders. Frédéric Darios received his PhD in
Biology of Aging in 2002 under the supervision of Dr. Merle Ruberg. He
investigated the importance of mitochondrial calcium levels in the induction of
cell death. This allowed him to propose for the first time a mitochondrial role for
Parkin, a protein associated with familial form of Parkinson’s disease. He then
joined the group of Dr. Bazbek Davletov at the Medical Research Council – Laboratory of Molecular
Biology (MRC-LMB, Cambridge, UK) for his post-doc, where he focused on the previously
uncharacterized function of lipids in the regulation of SNARE proteins and exocytosis. He demonstrated
that omega-3 and omega-6 polyunsaturated fatty acids can act on the SNARE protein syntaxin, while
another lipid, sphingosine, can act on a vesicular SNARE protein, synaptobrevin, to regulate the release
of neurotransmitter. This led to the discovery of a new role for alpha-synuclein, a protein associated
with Parkinson’s disease, but whose physiological function remains unknown. Since 2010, he is a
researcher at the Institut du Cerveau et de la Moelle Epinière (ICM, Paris, France), investigating the
physiopathology of hereditary spastic paraplegias. In 2012, he was awarded an ERC Starting Grant,
which allowed him to develop a research program leading the identification of altered lysosomal lipid
metabolism as a cause of neurodegeneration in the SPG11 form of hereditary spastic paraplegia.
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Alexandra Durr is university professor and consultant (PUPH) at the Hôpital de la Pitié-Salpêtrière in Paris. She has specialisation in neurology and genetics and has been developing translational neurogenetics for 25 years, based on a thorough clinical expertise that allowed her to identify the molecular bases of many pathologies. Alexandra Durr is a worldwide renowned expert of late-onset hereditary neurological diseases. She worked with premanifest individuals, i.e. mutation carriers without clinical signs of the disease, since 1992, pioneering the first presymptomatic structure for late onset neurological disorders in France. She has built up national and international collaborations from the beginning of her career. Genetic advances are used by her team at the ICM (Institut du Cerveau et de la Moelle épinière, Basic to Translational Neurogenetics co-directed by Giovanni Stevanin and Alexandra Durr) to understand pathophysiology and to set up innovative
therapies. In order to prepare this new era of genetic therapeutics, Alexandra Durr is taking advantage of the pre-manifest phase of neurodegenerative diseases and is, developing progression markers to determine the best therapeutic window, that will insure that the disease does not develop further. She coordinates of a national reference center for rare neurogenetic diseases and together with Giovanni Stevanin and Chantal Tallaksen they started the international SPATAX network in 2000.
Alexander Geurts received both his MD (1987) and PhD (1992) degree in Medical science at the Radboud University in Nijmegen. He was registered as a physiatrist by the European Board of Physical Medicine and Rehabilitation in 1997 and as a clinical epidemiologist in the Netherlands (SMWBO) in 2001. Since 1992, he continued his main research interest in balance, gait and motor recovery with a focus on neurorehabilitation, especially stroke rehabilitation and (hereditary) spasticity. He conducts both translational (determinants and mechanisms of motor
control and recovery) and applied research (development of diagnostic and prognostic tools, evaluation of interventions / rehabilitation strategies) both in adults and children with cerebral, spinal and neuromuscular diseases. He has been (co-) chair of several national research programmes in neurorehabilitation since 1998, including some successful innovation projects directed at the education of allied health professionals in stroke rehabilitation (NPI; www.paramedisch.org). In 2005, he has become full Professor and Chair of the Department of Rehabilitation at the Radboud University Medical Center and, since 2009, he has been PI at the Donders Centre for Brain Cognition and Behaviour. Alexander Geurts is vice-president of the Dutch Society for Neurorehabilitation (DSNR; www.neurorehab.nl), affiliated with the World Federation for Neurorehabilitation (WFNR). He has (co-) authored 232 PubMed registered articles (H-index 43).
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Prof. Henry Houlden. Our laboratory works on neurogenetics with a particular interest in spinocerebellar ataxia and movement disorders, particularly in diverse populations. We integrate new gene discovery such as CANVAS, SCA11, SCA15, genetics modifiers in the SCAs, using the latest genomic techniques with functional experimental validation in human tissue and other model systems. Our goal is to develop new therapeutics based on an improved understanding of disease mechanisms in children and adults. We recently established a collaborative project to genotype, and carry out a GWAS in SCA patients with
repeat expansions from around the world to identify genetic modifiers of age at onset and severity. As a group we are very keen to collaborate and keen to analyse further families, possible CANVAS and SCA patients in the age at onset GWAS. Email: [email protected]
Prof. Dr. med. Thomas Klockgether studied medicine at the University of Göttingen and during this time also carried out research at the Max Planck Institute for Experimental Medicine. After graduating, he went to Oldenburg for clinical training and then returned to the Max Planck Institute to work in basic research on Parkinson's disease. He completed his neurology training in Tübingen, where he also began to focus on degenerative ataxias, in addition to pursuing research on Parkinson’s disease. In 1998, he was appointed as Professor and Chair of Neurology at the University of Bonn. Prof. Klockgether has been the Dean of the Medical Faculty of the University of Bonn from 2008 to 2011. Since February
2010 he has been Speaker of the Center for Rare Diseases Bonn (ZSEB) and since May 2011 Director of Clinical Research at the DZNE.
Fanny Mochel is an associate professor of genetics at Sorbonne University in Paris. She received her MD in Genetics in 2005 at the University Paris Descartes, her PhD in Neuroscience in 2010 at Sorbonne University and is board certified in inborn errors of metabolism. Dr Mochel leads the French reference center on Neurometabolic diseases in adults and runs a Neurometabolic research group at the Brain and Spine Institute of La Pitié-Salpêtrière University Hospital in Paris. She is chair of the Adult group of the international Society for the Study of Inborn Errors of Metabolism and co-chair of the French society for inborn of errors of metabolism in adults. Her research is focused on the characterization and
treatment of brain energy deficiencies in neurometabolic and neurodegenerative diseases. Her major areas of expertise are the identification of neurometabolic biomarkers in vivo (metabolic imaging) and in vitro (metabolomics) as well as therapeutic approaches targeting the Krebs cycle.
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Dr. Gülin Öz is Professor at the Center for Magnetic Resonance Research (http://www.cmrr.umn.edu/), University of Minnesota and specializes in magnetic resonance spectroscopy (MRS). She graduated from Bosphorus University in Istanbul, Turkey with BS degrees in Physics and Chemistry and obtained her PhD in Biochemistry at the University of Minnesota. She continued with postdoctoral training at CMRR where she joined the faculty in 2006. Dr. Öz uses high field, multi-nuclear MRS to delineate neurochemical and metabolic alterations in diseases that affect the brain, in particular neurodegenerative diseases and diabetes. She leads a program in spinocerebellar ataxias and has studied neurochemistry in Parkinson’s,
Huntington’s, and Alzheimer’s diseases. She studies the effects of diabetes and the hypoglycemic consequences of intensive insulin therapy on brain glucose and glycogen metabolism in humans. She co-led an effort by the MRS Consensus Group, an international group of MR physicist and clinicians, to facilitate standardization of MRS methodology and to provide guidelines for data acquisition and analysis, quality assessment, and interpretation. She leads a multi-site Bioengineering Research Partnership (BRP) for across-platform harmonization of advanced MRS methods. Finally, she leads the imaging effort under the NIH-funded READISCA clinical trial readiness study for SCA1 and SCA3.
Dr Hélène Puccio, PhD. Research Director Inserm at the IGBMC. Head of Translational Medicine and Neurogenetics department. After obtaining her PhD degree in Genetics from Harvard University in 1998, Dr. Hélène Puccio joined the group of Professor Michel Koenig the Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC, Strasbourg, France) to work on the molecular pathogenesis of Friedreich ataxia. In 2000, she obtained a permanent scientific research position at INSERM (Institut National de la Santé et de la Recherche Médicale), and is now research director of the Fundamental and
pathophysiological mechanisms implicated in ataxia group at the IGBMC. Dr. Puccio laboratory is dedicated to unraveling the causes and mechanisms of progressive recessive ataxias linked to mitochondrial dysfunction, with a particular interest in Friedreich ataxia and Autosomal Recessive Cerebellar Ataxia 2. In addition, the laboratory is involved in the identification of novel causes of hereditary ataxia through next generation sequencing. Present position: Permanent research director (DR1) at the Institut National de la Santé et de la Recherche Médicale (INSERM). Group leader of the “Fundamental and pathophysiological mechanisms implicated in ataxia ” team in the department of Translational Medicine and Neurogenetics at the Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC).
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Agnès Rötig is a research director (DR1, INSERM) at Institut Imagine. She has built her research group more than 20 years ago in the field of mitochondrial disorders in very close collaboration with the Genetic Unit of Necker Hospital. Agnès Rötig has a longstanding collaboration with geneticist, pediatric neurology, neuroradiology and metabolic units from Necker hospital with the aim to identify nuclear genes of mitochondrial disorders and to understand their pathophysiology. Her group has set up the biochemical and genetic diagnosis of these diseases. Her team has described several novel genes responsible of these disorders and to establish genotype-phenotype correlations. Agnès Rötig has developed a patient
database that contains more than 1000 patients and their clinical, brain MRI features, metabolic, biochemical and genetic data. Moreover, her group associated with the clinical unit has set up a biobank containing tissue and/or fibroblasts of more than 1000 patients. Recently, her group has been involved in Neurodegeneration with Brain Iron Accumulation (NBIA) a genetically heterogeneous group of neurodegenerative disorders as NBIA patients present non specific clinical signs reminiscent to those observed in mitochondrial disorders. The mechanism of iron accumulation in these diseases is investigated thanks to collaboration with other groups of the Imagine Institut.
Rebecca Schüle is Coordinator of the TreatHSP.net Consortium. As a neurologist, she has been running the HSP outpatient clinic at the Center for Neurology in Tübingen for many years and is involved in national and international initiatives for a common, sustainable, harmonized and standardized collection of clinical data for the HSP (HSP Register). She is working on the development and validation of clinical and molecular biomarkers as outcomes parameters for clinical trials. Rebecca Schüle is intensively involved in the discovery of the genetic causes of HSP and models pathophysiological relationships in human stem cell models.
Isabel Silveira is group leader at IBMC-i3S, University of Porto, Portugal. She graduated in Pharmaceutical Sciences from the University of Porto. She then pursued her studies in Molecular and Cellular Biology at the University Paris V, France. She obtained her PhD degree in human genetics specializing in disease gene mapping. Her research group focuses on finding genes implicated in neurodegenerative diseases towards development of genetic diagnosis and treatment for these pathologies. In collaboration with a Galician team, she was involved in the finding of the GGCCTG repeat expansion in intron 1 of NOP56, in
SCA36. More recently, her team identified a non-coding ATTTC repeat insertion in a 5’UTR intron of DAB1 causing SCA37. They showed that overexpression of the ATTTC repeat triggers abnormal nuclear RNA accumulation. Her team also demonstrated that the AUUUC repeat RNA causes lethal developmental malformation when injected in zebrafish embryos. They are currently investigating RNA-mediated mechanisms leading to these diseases and how to rescue them.
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The research of Matthis Synofzik focuses on unravelling the molecular basis of hereditary ataxias, motor neuron diseases and dementias, identifying translational biomarkers, and preparing targeted treatments. He has a broad research and clinical background with specific expertise in next-generation genomics, deep-phenotyping, and translational studies, with now >200 PubMed listed peer-reviewed publications on these neurogenetic conditions. Following the launch of the German Early-Onset Ataxia Network in 2013, he has been coordinating the EU-funded global PREPARE consortium “Preparing therapies for autosomal-recessive ataxias” since 2016 which unites European and Canadian
centers to a common network to prepare molecular therapies for autosomal-recessive ataxias (ARCAs), and which has subsequently been joined by partners from all over the world (2019: 27 sites total). As part of this unique global collaborative effort for ARCAs, this consortium has now aggregated >1100 patient visits in a shared web-based longitudinal global ARCA registry, >900 biosamples from ARCA patients, and >1700 ataxia NGS datasets in the collaborative GENESIS platform. These large international ARCA networks and datasets of collaborative partners have now become the basis for the “ARCA GLOBAL” initiative - a worldwide multicenter translational initiative to pave the way for all crucial translational steps from NGS genetic fingerprinting to FDA-conform trial-readiness cohorts of ARCA patients.
André B.P. Van Kuilenburg received his MSc degree (Honours) in Chemistry (First Class in Biochemistry) in 1986 and his PhD in 1992 at the University of Amsterdam, the Netherlands. In 2003 he was registered as a specialist in clinical genetic laboratory diagnostics with emphasis on clinical biochemical genetics. In 2015 he was registered as a European Clinical Laboratory Geneticist. He is presently working as a clinical biochemical geneticist and Principal Investigator at the Amsterdam UMC and the University of Amsterdam. His main scientific interests are inborn errors of lysosomal storage disorders, purine and pyrimidine metabolism, pharmacogenetic aspects associated with inborn errors of the pyrimidine
degradation pathway and biochemical aspects of pediatric oncological diseases. He is an author of 291 scientific papers in peer reviewed international journals and books (Hirsch index 38). He is a member of the scientific committee of the Purine and Pyrimidine Society, a member of the registration committee of the Dutch society of Clinical Genetic Laboratory Diagnostics (VKGL) and the ERNDIM National Representative for The Netherlands.
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Frédéric Vaz got his master in chemistry at the University of Utrecht in 1997, specializing in biochemistry. In the Laboratory Genetic Metabolic Diseases in Amsterdam, headed by Professor Wanders, he performed his Ph.D. project and wrote his thesis on carnitine biosynthesis. As a postdoc, research on carnitine biosynthesis continued but the new subject of Barth syndrome got him interested in lipids, especially cardiolipin. During this period he was trained as a clinical biochemist specializing in inborn error of metabolism. He now is head of the metabolite section of the Laboratory Genetic Metabolic Diseases in Amsterdam,
responsible for diagnostics of inborn errors of metabolism as well as the head of the Core facility metabolomics of the AMC. His main goals are the continuing development of advanced lipidomics/metabolomics platforms - including the required bioinformatics- and their application for both research and diagnostic purposes. Email: [email protected]
Lucy Vincent after graduating from Sheffield University in the UK, studied neuroscience and pharmacology at the University of Bordeaux. After 2 years as a researcher with the CNRS working on brain plasticity she worked for several years on the communication of science in radio programs for Radio France and via the publication of a series of books for the French non-fiction publishing house Eds Odile Jacob. Today, following training as a ballroom dance teacher, she is again carrying out research on brain plasticity but this time under the influence of movement. She has recently started creating complex movement sequences
designed to produce benefits for physical and mental well-being, confidence, creativity and team spirit.
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Abstracts
Oral presentations
Abstract 7_ SCA48: molecular and clinical features of novel cases in a
multicentre Italian cohort Daniele Galatolo (1), Maria Lieto (2), Vittorio Riso (3), Giovanna De Michele (2), Salvatore Rossi (2), Melissa Barghigiani (1), Sirio Cocozza (4), Rosanna Trovato (1), Alessandra Tessa (1), Alessandro Filla (2), Giuseppe De Michele (2), Gabriella Silvestri (2,4), Filippo Maria Santorelli (1). (1) IRCCS Fondazione Stella Maris, Pisa, Italy; (2) Department of Neurosciences and Reproductive and Odontostomatological Sciences, Federico II University, Naples, Italy; (3) Institute of Neurology, Catholic University of the Sacred Heart, Rome, Italy; (4) Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy
Background Biallelic mutations in STUB1 were originally associated with spinocerebellar ataxia 16 (SCAR16). Recently, we and others described heterozygous mutations in STUB1 in a Spanish family and two Italian kindred with dominant spinocerebellar ataxia 48 (SCA48). We herein expand the STUB1-related allelic heterogeneity describing 11 SCA48 novel cases while we investigated a large Italian cohort of adult-onset degenerative spinocerebellar ataxias (SCA). Methods We assessed the prevalence of heterozygous STUB1 mutations (SCA48), in a cohort of 235 unrelated adult-onset, autosomal dominant or sporadic patients with degenerative ataxias, negative to SCA1, 2, 3, 6, 7, 17, FRDA and FXTAS genetic testing, by using targeted multigene panels or whole-exome sequencing. Bioinformatics analyses, reverse phenotyping and family segregation studies corroborated the pathogenicity of the novel mutations. Clinical and diagnostic findings were extensively reviewed to define the phenotypic spectrum. Results We identified 8 pathogenic STUB1 heterozygous mutations (6 of which novel) in 11 SCA patients from 8 index families. Patients presented with cerebellar ataxia, dysarthria, cerebellar atrophy and movement disorders. Psychiatric, cognitive features, or both, resembling a CCAS (Cerebellar Cognitive-Affective Syndrome) frequently occurred in the younger patients, whereas the older patients showed diffuse cognitive deterioration. Pyramidal signs and hypogonadism were seldom observed, whereas peripheral nervous system involvement was not involved. Conclusions Our results support SCA48 as a relatively common cause of adult-onset spinocerebellar ataxia. Besides CCAS, our SCA48 patients often manifest movement disorders, and other clinical manifestations previously described in SCAR16, thus suggesting a continuum clinical spectrum among recessively and dominantly inherited mutations in STUB1.
Abstract 15_Pathogenic ATG7 variants cause recessive cerebellar ataxia Claire Guissart (1), Jack Collier (2), Monika Olahova (2), Souphatta Sasorith (1), Pascal Joset (3), Pierre Meyer (4), Nicolas Leboucq (5), Lise Larrieu (1), Nuria Martinez-Lopez (2), Silvia Azzarello-Burri (3), Thomas McWilliams (6), Robert McFarland (2), François Rivier (4), Robert Taylor (2) and Michel Koenig (1). (1) EA7402 Institut Universitaire de Recherche Clinique, and Laboratoire de Génétique Moléculaire, University Hospital, Montpellier, France;(2) Wellcome Centre for Mitochondrial Research, Newcastle University, United Kingdom; (3) Institute of
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Medical Genetics, University of Zürich, Wagistrasse 12, Schlieren, Switzerland; (4) Department of Neuropédiatrie and CR Maladies Neuromusculaires, CHU de Montpellier, Montpellier, France;(5) Neuroradiologie, CHU de Montpellier, Montpellier, France;(6) Translational Stem Cell Biology & Metabolism Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
Autophagy is one of the major disease mechanisms leading to spinocerebellar ataxia. ATG7 encodes an enzyme that is essential for the autophagosome biogenesis. The conditional knockout mice with Purkinje cell-specific deletion of Atg7, was shown to develop cell-autonomous neurodegeneration of Purkinje cells, dendritic atrophy, and ataxic gait. Through a multi-centric collaboration, we report the identification of a novel clinical entity based on the discovery of 6 biallelic rare disrupting variants in the ATG7 gene of 5 affected individuals from three families (Family 1: [p.Arg659*];[c.2080-2A>G], family 2: [p.Arg576His];[p.His624Tyr], family 3:[p.Pro234Thr];[p.Val588Met]). In silico modeling points to altered ATG7 homodimer formation as a result of the three C-terminal missense variants (p.Arg576His, p.Val588Met, and p.His624Tyr). Autophagosome formation appeared normal in the patient fibroblasts of families 1 and 2. Interestingly, patients with the truncating mutations (family 1) displayed a mild phenotype with moderate ataxia and facial dysmorphism while the fibroblasts showed undetectable levels of ATG7 and absence of activated LC3-II, a key component in autophagosome formation. By contrast, we observed severe ataxia and developmental delay in subjects from family 2 (with missense mutations) while ATG7-dependent autophagy appeared to be mildly impacted with moderately reduced levels of ATG7 and LC3-II. Surprisingly, the two patients of family 2 showed lower steady-state levels of Rab9 (alternative autophagy) than controls and family 1 patients, potentially explaining the more severe phenotype. Our combined genetic and functional data highlight a complex mutational interplay at the human ATG7 locus and suggest that alternative autophagy may take over from the ATG7-dependent pathway, as an explanation for the difference of severity between patients with truncating or missense mutations.
Abstract 27_Safety and efficacy of Interferon γ in Friedreich ataxia: a pilot trial with clinical and paraclinical endpoints.
Andrea Martinuzzi1, Marinela Vavla1, Grazia D’Angelo1, Filippo Arrigoni1, Nicola Toschi2.4, Denis Peruzzo1, Sandra Gandossini1, Annamaria Russo1, Eleonora Diella1, Roberto Salati1, Paolo Scarpazza1, Riccardo Luffarelli2,3, Silvia Fortuni2, Alessandra Rufini2,3, Ivano Condò2, Roberto Testi2,3
1) Scientific Institute, IRCCS E. Medea, via Don Luigi Monza 22, 23842 Bosisio Parini (LC) Italy 2) Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, via Montpellier 1, 00132 Rome, Italy 3) Fratagene Therapeutics, Rome, Italy 4) Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Boston, MA, USA
Background. Friedreich ataxia (FRDA) is a devastating neurodegenerative disease that still lacks a cure. Clinical features are dominated by the progressive loss of motor coordination and balance. A dilated cardiomyopathy, which eventually causes heart failure, is often associated. Among the several therapeutic approaches under study, interferon gamma (IFN ) appears promising, however definitive evidence of its efficacy is still missing.
Methods. The safety and efficacy of IFN was investigated in 11 FRDA patients over a treatment period of 6 months, in an open-label clinical trial. Primary efficacy outcomes were clinical measures, i.e. the SARA scale. Secondary outcomes were disability and quality of life measured by WHO-DAS and SF-36 questionnaires, PBMC frataxin levels by immunoblotting,
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cardiac structure and function by echoCG and ECG, the structure of the retina by OCT, and the structure and function of the brain by MRI.
Findings. IFN treatment was generally well tolerated. IFN completely stopped the progression of the SARA score during the 6-months treatment period, compared to the 6 months preceding the treatment (p < 0·009). IFN reduced the thickness of the cardiac interventricular septum and reduced the Sokolow-Lyon index, with a rebound after treatment discontinuation. It enhanced the activation of the left motor cortex during dominant hand movements and affected the activity of three resting state brain networks. Also, the enhanced activation of the right motor cortex, during bilateral hand movements, correlated with SARA score changes. Other measures did not show significant changes.
Interpretation. Although the size of the study population and the trial design do not allow definitive conclusions, the results point toward the efficacy of IFN in affecting the progression of the disease. The wide set of efficacy measures used in this study may provide guidance for future placebo-controlled clinical trials.
Abstract 38_Cerebellar transcranial direct current stimulation in spinocerebellar ataxia type 3 (SCA3-tDCS): rationale and protocol of a randomized, double-blind, sham-controlled study
Roderick P.P.W.M. Maas1, Ivan Toni2, Jonne Doorduin1, Thomas Klockgether3, 4, Dennis J.L.G. Schutter2, Bart P.C. van de Warrenburg1 1 Department of Neurology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands 2 Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, the Netherlands 3 Department of Neurology, University of Bonn, Bonn, Germany 4 German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany Corresponding author Roderick Maas, MD Department of Neurology & Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center Reinier Postlaan 4, 6525 GC Nijmegen, the Netherlands PO Box 9101, 6500 HB Nijmegen, The Netherlands (t) 0031-24-3613396 (f) 0031-24-3541122 (e) [email protected]
Background: Recent investigations in a heterogeneous group of hereditary and acquired ataxias showed promising, prolonged effects of a two-week course with daily sessions of cerebellar anodal transcranial direct current stimulation (tDCS) on ataxia severity, gait speed, and upper limb dexterity. The aim of the SCA3-tDCS study is to further examine whether tDCS improves ataxia severity and non-motor symptoms in a homogeneous cohort of SCA3 patients and to explore the time course of these effects.
Methods/design: A double-blind, randomized, sham-controlled, single-center trial will be conducted. Twenty mildly to moderately affected SCA3 patients (SARA score between 3 and 20) will be included and randomly assigned in a 1:1 ratio to either cerebellar anodal or sham tDCS. Patients, investigators, and outcome assessors are unaware of treatment allocation. Cerebellar tDCS (20 minutes, 2 mA, ramp-up and down periods of 30 seconds each) will be delivered over ten sessions. Outcomes are assessed after a single session of tDCS, after the tenth stimulation (T1), and after three, six, and twelve months. The primary outcome measure is the absolute change of the SARA score between baseline and T1. In addition, effects on various other motor and neuropsychological functions in which the cerebellum is known to be
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involved will be evaluated using quantitative motor tests, static posturography, neurophysiological measurements, cognitive assessment, and questionnaires.
Discussion: The results of this study will inform us whether repeated sessions of cerebellar anodal tDCS benefit SCA3 patients and whether this form of non-invasive stimulation might be a novel therapeutic approach to consider in a neurorehabilitation setting.
Accepted for publication by BMC Neurology.
Abstract 45_Single-intrathecal delivery of a new AAV9-mediated gene therapy
vector provides long-term safe expression of frataxin and prevents
neurodegeneration in a Friedreich Ataxia mouse model.
E.Balagué1, D.Cota-González1, K.Adrián-Campbell1, B.García-Lareu2,3, A.Bosch2,3, J.Coll-Cantí4, M.Chillón5,6,7, I.Sánchez-
Diaz1, A.Matilla-Dueñas1
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1. Translational and Functional Neurogenetics Unit, Department of Neuroscience, Germans Trias Research Institute (IGTP),
Universitat Autònoma de Barcelona-Campus Can Ruti, Badalona.
2. Institut de Neurociències (INc), Departament Bioquímica i Biologia Molecular, Universitat Autònoma Barcelona, Bellaterra,
Spain.
3. Department of Biochemistry and Molecular Biology, Universitat Autònoma Barcelona 5th level, Edifici H, Institut Neurociencies,
Campus UAB, Bellaterra, Spain.
4. Unitat de Neuromuscular, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
5. Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
6. Vall d'Hebron Institut de Recerca, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
7. Vector Production Unit (UPV), Universitat Autònoma Barcelona, Barcelona, Spain.
Friedreich's ataxia (FRDA) is a recessively inherited neurodegenerative disease caused by frataxin (FXN) deficiency. FRDA is characterised by progressive ataxia, sensory loss and hypertrophic cardiomyopathy. Neurodegeneration is identified in DRG neurons, peripheral sensory nerves, the posterior column, and cerebellar dentate nucleus. To date, proof-of-concept approaches have clearly highlighted the therapeutic potential of AAV-gene therapy in FRDA. However, these studies have used synthetic promoters providing high-yields of FXN levels and which are known to shut-down over time. Recent data point to the importance of maintaining frataxin levels within a range due to potential toxicity. To address this, we generated a new AAV9-gene therapy vector encoding a DNA sequence for frataxin regulated by the hPGK1 promoter and the WPRE element, which provides a constitutive, ubiquitous, and long-term expression in the YG8R FRDA mouse model. We show that a single intrathecal administration of this vector into two-month-old FRDA mice effectively transduces frataxin into DRG, spinal cord, cerebellum, brain, heart, liver and pancreas and expresses recombinant frataxin for at least 12 months with no apparent vector-induced toxicity. We demonstrate that the levels of recombinant frataxin in treated mice were similar to the endogenous frataxin levels in the WT mice. AAV-FXN treated FRDA mice show significant preservation of motor coordination, the electrophysiological properties in sensory caudal nerve, the hindlimb clasping reflex, and neuronal structural preservation of the DRG, spinal cord and dentate nucleus. Our data provide support for the clinical therapeutic potential of this gene therapy vector for the treatment of Friedreich’s ataxia.
Abstract 52_CONFIDENTIAL
Abstract 54_Neurofilaments as blood biomarkers at the preataxic and ataxic
stage of spinocerebellar ataxia type 3: a cross-species analysis in humans and
mice
Carlo Wilke 1,2, Kathrin Reetz3,4, Thomas Klockgether 5,6, Ludger Schöls1,2, European Integrated Project on Spinocerebellar
Ataxias (EUROSCA/RISCA), European Spinocerebellar Ataxia Type 3/Machado-Joseph Disease Initiative (ESMI), Christian
Barro7,*, Jeannette Hübener-Schmid 8,*, Matthis Synofzik1,2,*
1 Hertie-Institute for Clinical Brain Research (HIH) and Center of Neurology, University of Tübingen, Germany.
2 German Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Germany.
3 Department of Neurology, RWTH Aachen University, Aachen, Germany
4 JARA-BRAIN Institute Molecular Neuroscience and Neuroimaging, Forschungszentrum Julich, RWTH Aachen University,
Aachen, Germany
5 Department of Neurology, University Hospital Bonn, Bonn, Germany
6 German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
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7 Neurology, Departments of Medicine, Biomedicine and Clinical Research, University Hospital Basel, University of Basel,
Basel, Switzerland
8 Institute of Medical Genetics and Applied Genomics, University of Tübingen, Germany.
* Joined last authors
Background. With targeted molecular therapies (e.g. antisense oligonucleotides) at reach, easily accessible biomarkers are needed for SCA3. We hypothesised that serum neurofilaments might serve as blood biomarkers of disease progression in human SCA3 and mouse models. Methods. Serum neurofilament light (NfL) and phosphorylated neurofilament heavy (pNfH) levels were determined by ultra-sensitive single molecule array (Simoa) in cross-sectional samples of (i) ataxic and preataxic SCA3 subjects and controls in two independent cohorts (ESMI cohort= cohort#1: n=160, EuroSCA/RISCA cohort = cohort#2: n=89) and (ii) ataxic and presymptomatic 304Q SCA3 knock-in mice (n=147). Findings. Ataxic SCA3 subjects showed increased serum NfL (p<0.001) and pNfH (p<0.001) levels in cohort #1, with NfL levels already increased in preataxic subjects (p<0.001). All of these results were replicated in cohort #2 (all p<0.001). Cross-sectional NfL levels correlated with clinical disease severity (SARA; r=0.46, p<0.001; cohort #1) and with longitudinal disease progression (annual SARA score change, ϱ=0.42, p=0.012; cohort #2). NfL levels in preataxic subjects increased with proximity to individual expected onset of ataxia (p<0.001), with significant elevations already 7.5 years before onset. Serum NfL and pNfH increases in SCA3 humans were paralleled by similar changes in SCA3 knock-in mice, here also already starting at the presymptomatic stage and including pNfH increase, and close to onset of ataxin-3 increase. Interpretation. Serum concentrations of neurofilaments, particularly NfL, might provide easily accessible biomarkers of disease severity in ataxic and preataxic SCA3 subjects and mice, with potential applications as progression, onset/proximity and treatment-response markers in both human and murine SCA3 trials.
Abstract 56_ PATHOGENIC RCF1 REPEAT EXPANSION: A FREQUENT CAUSE
OF LATE-ONSET ATAXIA IN SPANISH POPULATION
Avila-Fernandez A1, Gallego-Merlo J1, Perez Gaya T2, Giménez-Pardo A1, Horcajada L1, Arteche- Lopez A3, Fenollar-Cortes M4, Swafiri ST1, Rodriguez-Pinilla E1, Rodriguez-Peña L5, Guillen-Navarro E5, Martínez-Pueyo A6, García-Ruiz Espiga P6, Ayuso C1, Lorda I1, Trujillo-Tiebas MJ1. 1 Genetics Department. Fundación Jiménez Díaz University Hospital, Madrid (Spain) 2 Clinical analysis Department. Fundación Jiménez Díaz University Hospital, Madrid (Spain) 3 Genetics Department. 12 de Octubre University Hospital, Madrid (Spain) 4 Clinical Genetics Section. Clinical analysis Department. San Carlos Clinic Hospital, Madrid (Spain) 5 Medical Genetics Section. Virgen de la Arrixaca University Hospital, Murcia (Spain) 6 Neurology Department. Fundación Jiménez Díaz University Hospital, Madrid (Spain)
A pathogenic RFC1 repeat expansion has been recently described as a frequent cause of late-onset ataxia accounting with 20% of the cases in Caucasians. The aim of this study is to establish the prevalence of the RCF1 expanded alleles in Spanish patients. A total of 78 Spanish patients diagnosed with late-onset ataxia, without evidence of vertical transmission, were screened. Other common ataxias had been previously discarded. The screening of the RCF1 repeat expansion was performed as described in Cortese et al. Biallelic AAGGG expansion was found in 8 out of 78 patients. Also, biallelic AAAGG expansion was observed in 2 unrelated patients, reaching a diagnostic rate of 13% (10/78). Additionally, in our cohort of patients, 10 heterozygous AAGGG were detected.
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Mean age of ataxia onset among the RCF1 repeat expansion patients was 57 (25-78) years. All of them complain about unsteadiness at disease onset. At least 80% of patients present signs of cerebellar involvement and 60% had sensory neuropathy. Other clinical features are under examination. In summary, the RFC1 repeat expansion seems to be a frequent cause of Spanish late-onset ataxia. Furthermore, this is first biallelic AAAGG expansion found as associated with the disease. The high frequency of heterozygosity in our cases suggests that another kind of pathogenic variants in RCF1 may cause this type of ataxia. Finally, due to the high diagnostic rate, we propose the implementation of this study into routine diagnostic in patients with ataxia, followed by mutation sequence screening in those heterozygote cases for the expansion.
Abstract 65_ CONFIDENTIAL
Abstract 70_ A double-blind, randomized, placebo-controlled, crossover trial of
botulinum toxin type A in hereditary spastic paraplegia - the SPASTOX trial
Fabricio Diniz de Lima (1), Ingrid Faber de Vasconcellos (1), Katiane Raisa Servelhere (1), Maria Fernanda Ribeiro Bittar (1), Alberto Rolim Muro Martinez (1), Luiza Gonzaga Piovesana (1), Carlos Roberto Martins Jr (1), Tatiana Benaglia (1), Benilton de Sá Carvalho (1), Anamarli Nucci (1), Marcondes Cavalcante França Jr (1) (1) Neuromuscular Division, Department of Neurology, University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil
Introduction: Hereditary spastic paraplegias (HSP) are a group of diseases characterized by lower limb spasticity and weakness. Spasticity reduces gait quality and velocity producing incapacity, but its best management strategy is not well elucidated. Then, we designed the SPASTOX trial to evaluate the efficacy and safety of botulinum toxin type A (BTX-A) in patients with HSP. Methods: Participants were assigned to receive BTX-A and saline 0.9%, separated by a period of 6 months. Primary outcome measure was change from baseline in maximal gait velocity assessed through a 10-meter walk test (10mWT) and secondary outcome measures included changes from baseline in comfortable gait velocity through 10mWT, spasticity (MAS), muscle strength (MRC), Spastic Paraplegia Rating Scale (SPRS), pain (BPI-S and BPI-I), fatigue (MFIS) and subjective perception of improvement (SPI). We also looked at adverse effects (AE). Results: Fifty-five HSP patients were enrolled. Mean age, age at onset and disease duration of patients was 43, 27 and 17 years, respectively. There were 36 men and 41 with pure phenotype. Mean maximal gait velocity did not differ between treatment or placebo groups after 8-weeks (p=0.408) as well as comfortable gait velocity (p=0.292), even with reduction in adductors tone (p=0.002), which was accompanied by diminution in its muscle strength (p=0.043). We did not find significant differences regarding SPRS (p=0.417), BPI-S (p=0.825), BPI-I (p=0.714), MFIS (p=0.874), SPI (p=0.253) and AE between treatments (p=0.156). Conclusion: Despite BTX-A representing a safe treatment, no statistically significant effectiveness was demonstrated to HSP patients according to the measures and instruments used.
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Abstract 72_ Speech and swallowing deficits are detectable at the pre-ataxic
stage of Spinocerebellar Ataxia Type 2
Adam P. Vogel 1, 2, 3 (PhD), Michelle Magee 1 (PhD), Reidenis Torres Vega (MSc) 4, Melissa P Cyngler 1 (MSc), Megan Kruse 1
(MSc), Sandra Rojas (MSc) 1, Sebastian Contreras Cubillos (MSc) 5,6, Tamara Canento (MD) 1, Fernanda Maldonado 1, Winfried
Ilg 2,8 (PhD), Jacqueline Medrano-Montero 4 (DSc), Roberto Rodríguez-Labrada 4 (PhD), Luis Velázquez-Pérez* (MD, PhD) 4,
Matthis Synofzik* 2,8 (MD)
1 Centre for Neuroscience of Speech, The University of Melbourne, Victoria, Australia 2 Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tübingen, Germany & Center for
Neurology, University Hospital Tübingen, Germany 3 Redenlab, Australia 4 Center for Research and Rehabilitation of Hereditary Ataxias (CIRAH), Holguin, Cuba 5 University of Santo Tomas, Talca-Chile 6 Escuela de Fonoaudiologia, Facultad de Salud, Universidad Santo Tomas, Chile; 7 Physical Medicine & Rehabilitation Service, Speech Therapy Unit, Hospital of Curico-Chile. 8 German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
* joint senior authors
Background: Speech and swallowing deficits are common in spinocerebellar ataxias (SCAs)
yet the nature and severity of SCA genotype-specific deficits, namely evolution at the pre-
ataxic to the early-manifest stages are not well characterized. Comprehensive objective and
qualitative assessment of dysarthria and dysphagia in SCA2 specifically, early disease phases
can inform timely targeted neurorehabilitative interventions and provide outcome measures in
future treatment trials.
Methods: Forty-six individuals (16 pre-ataxic SCA2, 14 early-stage ataxic SCA2 and 16
healthy control subjects) were recruited in Holguin, Cuba. All participants underwent a
comprehensive battery of assessments including objective acoustic analysis, subjective
clinician derived ratings of speech function and swallowing, and quality of life assessments of
swallowing.
Results: Speech deficits manifest from reduced diadochokinetic (DDK) rate, increased DDK
period at the pre-ataxic stage, with increased changes at the early-ataxic stage. Additionally,
speech rate was slower in early-stage ataxic SCA2 compared with pre-ataxic SCA2 and
healthy controls. Reduced speech agility and slower speech rate were associated with disease
severity. Furthermore, perturbation of DKK period and slower speech rate correlated with time
to ataxia onset, confirming speech deficits occurred prior to ataxia onset and increase in
severity as the disease progresses. Whilst dysphagia was observed in both pre-ataxic and
ataxic SCA2, it was not associated with swallowing-related quality of life, disease severity or
time to ataxia onset.
Conclusions: Speech and swallowing deficits appear sensitive to disease progression in
early-stage SCA2, with syllabic rate a viable marker. Findings provide insight into the
underlying mechanisms of disease progression in early-stage SCA2 and signal an opportunity
for stratifying early-stage SCA2 patients and identifying salient markers of disease onset as
well as outcome measures in future early-stage treatment intervention studies.
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Abstract 75_ Organellar proteomics to investigate the mechanism that underlies
the neuronal pathology of AP-4 deficiency
Alexandra K. Davies (1,2), Daniel N. Itzhak (1,3), James R. Edgar (2,4), Adam C. O’Neill (5,6), Julia P. Schessner (1), Magdalena
Götz (5,6), Margaret S. Robinson (2), Georg H. H. Borner (1).
(1) Max Planck Institute of Biochemistry, Martinsried, Germany;
(2) Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK;
(3) Cell Atlas Initiative, Chan Zuckerberg Biohub, San Francisco, USA;
(4) Department of Pathology, University of Cambridge, Cambridge, UK;
(5) Institute for Stem Cell Research, Helmholtz Center, Munich, Germany;
(6) Biomedical Center, Ludwigs-Maximilians University, Munich, Germany.
Adaptor protein complex 4 (AP-4) is an ancient but poorly understood membrane trafficking
complex. Mutations in any of the four subunits of AP-4 cause intellectual disability and spastic
paraplegia (SPG47/50/51/52). AP-4 deficiency is a disease of missorting; therefore, we seek
to identify proteins that are missorted in the absence of AP-4, by applying unbiased proteomic
approaches. We previously used ‘Dynamic Organellar Maps’, a method that provides protein
subcellular localisation information at the whole proteome level. This revealed three
ubiquitously expressed transmembrane cargo proteins, ATG9A, SERINC1 and SERINC3, to
be mislocalised in AP-4 knockout HeLa cells. Further orthogonal proteomic approaches
identified two novel AP-4 accessory proteins, RUSC1 and RUSC2. RUSC2 facilitates the
microtubule plus-end-directed transport of AP-4-derived, ATG9A- and SERINC-positive
vesicles from the TGN to the cell periphery. Our lab and others have since demonstrated that
accumulation of ATG9A at the TGN is a hallmark of AP-4 deficiency in diverse cell types,
including in patient fibroblasts and primary neurons from AP-4 knockout mice.
ATG9A has an important role in autophagy – a pathway that is implicated in diverse
neurodegenerative disorders. Thus, the neuropathology of AP-4 deficiency may be caused, at
least in part, by inefficient delivery of ATG9A to the distal axon. However, this does not
preclude the possibility that AP-4 has further neuron-specific cargoes. To investigate this, we
are now applying organellar proteomics to study neuronal models of AP-4 deficiency, including
tissue and primary neurons from AP-4 knockout mice and human induced pluripotent stem
cell-derived cortical neurons.
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Abstracts
Poster presentations
Abstract 1_ CONFIDENTIAL
Abstract 2_ Hereditary spinocerebellar degeneration in Sudan: identification of variants in known and new genes in a large cohort
Ashraf Yahia1,2,3, Melanie Papin2,3, Typhaine Esteve2,3, Inaam N. Mohammed1, Ahlam A. A. Hamed1, Maha A. Elseed1, Aisha Bakheit1, Maha Elzubair1, Sarah Elsadig1, Mahmoud E. Koko4,
Julian Schubert4, Rayan A. Siddig1,
Isra Zuhir1, Fatima Abuzar1,
Mohammedalhassan Musallam1, Sara Emad1, Rawa Adil1, Mayada Osama1, Eman Osama1, Arwa Babai1, Hiba Malik1, Mutaz Amin1, Ali Ahmed1, Zulfa Omer1, Ahmed Khalid1, Razaz Idris1, Shaimaa Omer Taha6, Hassab Elrasoul SA Mohamed7, Elfatih Bushara1, Salah Elmalik8, Muddathir H A Hamad5, Mustafa A. Salih5, Mustafa Elbashir1, Muntasir Ibrahim9, Holger Lerche4, Alexis Brice2,10, Liena E. O. Elsayed1, Ammar E. Ahmed1, and Giovanni Stevanin2,3,10.
*Correspondence: Professor Giovanni Stevanin, Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Sorbonne Universités, UPMC Université Paris VI UMR_S1127, 75013 Paris, France. Email: [email protected] 1Faculty of medicine, University of Khartoum, Khartoum, Sudan. 2Institut du cerveau et de la moelle épinière, INSERM U1127, CNRS UMR7225, Sorbonne Universités Paris VI UMR_S1127, 75013 Paris, France. 3Ecole pratique des hautes etudes, EPHE, PSL université, 75013 Paris, France. 4Department of neurology and epileptology, Hertie institute for clinical brain research, University of Tübingen, Germany. 5Department of pediatrics, College of medicine, King Saud University, Riyadh, Saudi Arabia. 6Department of radiology, Dar Al Elaj specialized hospital, Khartoum, Sudan. 7Alnelain medical center, Khartoum, Sudan. 8Department of physiology, College of medicine, King Saud University, Riyadh, Saudi Arabia. 9Institute of endemic diseases, University of Khartoum, Sudan. 10APHP Pitié-Salpêtrière hospital, Department of genetics, 75013 Paris, France.
Introduction: Hereditary spinocerebellar degeneration (SCD) encompasses a spectrum of clinically and genetically heterogeneous disorders, with phenotypes ranging from pure spastic paraplegia or pure cerebellar ataxia to more complex forms. Sudan is located in east Africa which is a region known for the high genetic diversity among its population. The Sudanese population is characterized by high rates of consanguineous marriages (40-49%).
Methodology: We used next generation sequencing targeted genes panel screening and whole exome sequencing to study 25 Sudanese families with SCD. We analyzed the sequencing data using online and in-house bioinformatic tools. We confirmed the segregation of the identified candidate variants with the disease phenotype in the studied families using Sanger sequencing.
Results: We identified 26 culprit variants, 20 of these were in 15 genes previously linked to SCD and six were located in six new candidate genes never linked to pathological human phenotypes. Three of the variants were possible founder variants: NM_024306.4(FA2H):c.674T>C and NM_021222.2(PRUNE1):c.132+2T>C, each in two families; NM_138422.3(ADAT3):c.430G>A in one of our families and was previously identified in families from the gulf area. Furthermore, we detected dystonia as a new extension of the PRUNE associated phenotype and spastic paraplegia and developmental delay as the main presentation of DMXL2 associated disorder.
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Conclusion: We studied 25 Sudanese families with hereditary spinocerebellar degeneration, and we identified the causative mutations in 88% of these families. The 26 culprit variants were found in 15 genes previously linked to the phenotype and in six new candidate genes under validation through functional studies.
Abstract 3_ Identification of the underlying pathogenic pathways in a mouse model in Hereditary Spastic Paraplegia SPG11 through transcriptional study
Typhaine Esteves (1,2), Julien Branchu (1), Liriopé Toupenet (1,2), Khalid Hamid El Hachimi (1,2), Frédéric Darios (1), Giovanni Stevanin (1,2). (1) Institut du Cerveau et de la Moelle épinière / CNRS UMR7225 / INSERM U1127/ Sorbonne Université, Paris, France (2) Ecole Pratique des Hautes Etudes, Paris, France
Hereditary spastic paraplegias are rare inherited neurological diseases characterized by a large heterogeneity in both clinical and genetic aspects. Mutations in SPG11 account for the most common form of autosomal recessive cases. Patients present mainly with spasticity associated with neuropathy and mental impairment. This gene encodes the protein spatacsin, with still unknown function.
Nevertheless, spatacsin is known to be involved in lysosomal recycling, and interacts with the AP-5 complex involved in membrane sorting.
The Spg11 knockout mouse recapitulates the full range of symptoms associated with SPG11 mutations observed in patients. To understand the molecular changes in the brain of those mice (KO versus WT), we sampled mRNA from cortex, cerebellum and hippocampus at 3 different ages (6 weeks, 4 and 8 months) corresponding respectively to the onset of symptoms, the occurrence of the full clinical features and the onset of neurodegeneration. RNAseq was performed using the NextSeq500 sequencer.
As expected, SPG11 mRNA levels were decreased. Then, we also found a dozen of deregulated genes involved in the lysosomal pathway, according to the role of spatacsin in this cellular function.
Although spatacsin interacts with AP-5 complex members, we found none of them deregulated at the mRNA level, which does not exclude a post-traductional regulation of those partners.
More interestingly, we found that the most deregulated genes were involved in lipid metabolism, supporting recent studies in SPG11 in which lipidic accumulations have been observed.
Further analyses are ongoing to identify new interesting targets and decipher the mechanisms involved in this pathology.
Abstract 4_ Spatacsin’s role in lysosome recycling and lipid clearance
Maxime Boutry, Alexandre Pierga, Raphaël Matusiak, Julien Branchu, Marc Houllegatte, Yoan Ibrahim, Elise Balse, Khalid-Hamid El Hachimi, Alexis Brice, Giovanni Stevanin, Frédéric Darios
Equipe Stevanin-Durr, Institut du Cerveau et de la Moelle Epinière/CNRS UMR 7225/INSERM 1127/Sorbonne Université, Paris, France
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Hereditary Spastic Paraplegias (HSP) are a group of genetic neurodegenerative diseases characterized by progressive spasticity and weakness of lower limbs. These symptoms are caused by the degeneration of motor neurons of the cortico spinal tract. The most frequent form of autosomal recessive HSP is due to mutations in SPG11, coding for spatacsin.
Loss of spatacsin function impairs Autophagic Lysosomal Reformation1, a mechanism that allows the recycling of membrane from autolysosomes after autophagy to promote the reformation of new lysosomes2.
Results from the lab have shown that in absence of spatacsin, lysosomes of fibroblasts produce less tubules, indicating that there is an impairment in the lysosomal membrane recycling. Moreover, in absence of spatacsin, cultured mouse neurons and cultured mouse fibroblasts accumulate lipids in their lysosomes.
In this project, we investigate the role of spatacsin and the link between the impairment of lysosomal membrane recycling and lipid accumulation in lysosomes.
It appears that tubular structures emerging from Lamp1-positive vesicles contain cholesterol, so the impaired recycling of lysosomes can be responsible for lipid overload in lysosomes. The cholesterol homeostasis impairment in absence of spatacsin is linked with a calcium homeostasis impairment with abnormal cytosolic and lysosomal calcium levels. Interestingly, modulating calcium levels with specific drugs will restore tubulation in fibroblasts and normal lipid levels in lysosomes. In neurons, the elevated cholesterol level in lysosomes in absence of spatacsin is restored by treatments targeting calcium levels but the ganglioside level remain unaffected. Ganglioside and cholesterol levels in lysosomes of neurons are independent : artificially lowering cholesterol levels with the use of statins has no consequence on ganglioside level. More investigations are required to determine the cellular location of spatacsin and its role in lysosomes dysfunctions. 1. Chang, J., Lee, S., and Blackstone, C. (2014). Spastic paraplegia proteins spastizin and spatacsin mediate autophagic lysosome reformation. J. Clin. Invest. 124, 5249–5262. 2. Chen, Y., and Yu, L. (2017). Recent progress in autophagic lysosome reformation. Traffic 18, 358–361.
Abstract 5_ CONFIDENTIAL
Abstract 6_ Familial hemiplegic migraine and MRS abnormality in a SLC1A3 mutation responsive to acetazolamide
Martin Paucar1,2, Tobias Granberg2,3, Sven Pettersson4, Love Nordin4,5, Per Svenningsson1,2
1Department of Neurology, Karolinska University Hospital, 2Department of Clinical Neuroscience, Karolinska Institutet, 3Department of Radiology, Karolinska University Hospital, 4Department of Diagnostic Medical Physics, Karolinska University Hospital, 5Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
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Objective: To characterize a family featuring familial hemiplegic migraine and cerebellar abnormalities associated with a new mutation in SLC1A3.
Background: Heterozygous mutations in SLC1A3, encoding glial glutamate transporter, are associated with episodic ataxia type 6 (EA6). EA6 is one of the rarest forms of paroxysmal ataxia; only once before has a SLC1A3 mutation carrier been reported as associated with familial hemiplegic migraine.
Methods: Oral and written consent were obtained from both the index case and her mother. Both were examined with SARA and INAS, structural imaging with MRI and genotyping. The index case went through MRS before and after treatment with acetazolamide (ACZ) and neurophysiological tests.
Results: The index case is a 24-year-old woman with recurrent episodes of right side hemiplegic migraine triggered by menstruation. Onset was at age 18. The episodes last for hours and resolves spontaneously. Examination demonstrated interictal nystagmus but not signs of ataxia. EEG and ENeG were normal. She harbors the novel c379_383del variant in SLC1A3. Treatment with ACZ prevented hemiplegic migraine. In addition, this patient had mild vermis atrophy. Her 50-year-old mother has migraine with aura but denies hemiplegic and ataxia episodes. Her brain MRI was normal but she declined MRS and other tests. The index went through MRS before and after treatment with ACZ. This study demonstrated an abnormal Glx (Glu and Gln) peak restored to normal levels after treatment was initiated. Unrelated to the SLC1A3 mutation, the index case developed Cushing’s syndrome due to an adrenal tumor removed this year. This tumor motivated a right side nephrectomy and adrenalectomy. Further investigation revealed lung metastasis.
Conclusions: Based on a previous finding a more severe phenotype was expected for the truncating mutation. This and the scarce number of publications, eight in total, limit attempts to establish genotype-phenotype correlations for mutation in SLC1A3. Our work expands the spectrum of SLC1A3 mutations, illustrates the benefit of treatment with ACZ and the utility of MRS in the diagnosis of altered glutamate transport.
References:
1. de Vries, B. et al . Episodic ataxia associated with EAAT1 mutation C186S affecting glutamate reuptake. Arch. Neurol. 66: 97-101, 2009.
2. Jen, J. C., et al. Mutation in the glutamate transporter EAAT1 causes episodic ataxia, hemiplegia, and seizures. Neurology 65: 529-534, 2005.
3. Pyle, A., et al. Exome sequencing in undiagnosed inherited and sporadic ataxias. Brain 138: 276-283, 2015.
Abstract 9_ A novel ADCK3 mutation in a sibpair with cerebellar ataxia.
Elisabetta Indelicato1, Wolfgang Nachbauer1, Andreas Eigentler1, Matthias Amprosi1, Stephanie Mangesius2, Elke R. Gizewski2, Sylvia Boesch1
1Ataxia Unit, Department of Neurology, Innsbruck Medical University 2 Department of Neuroradiology, Innsbruck Medical University
Background: A sibpair from healthy parents was referred to our ataxia outpatient clinic because of a chronic cerebellar syndrom and writer´s cramp with early onset. At first examination the sister was 45 and the brother 28 years old.
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Methods: An extensive evaluation was performed including general and neurological examination, laboratory testing, neurophysiological studies, neuropsychological testing and MRI-imaging with spectroscopy.
Results: Both siblings showed a pure cerebellar syndrome (SARA score at the first examination 13 in the sister and 10 in the brother) with dysarthria, limb dysmetria and gait ataxia as well as a task specific dystonia while writing. The writer´s cramp was the first symptom of the disease in both siblings and appeared at the age of 7 in the male and in the mid twenties in the female patient. MRI imaging showed an isolated cerebellar atrophy, more marked in the upper vermis; MR-H1 spectroscopy of the cerebellum was normal in both patients. Exome-sequencing revealed a homozygous variant in ADCK3 (c.656-1G>T) in both siblings with an in-silicio prediction of an aberrant splicing. This mutation was not previously described in the literature. Coenzyme Q10 substitution was prescribed. In 1-year follow-up patients reported no substantial worsening of their skills. Coenzyme Q10 dose was increased and further clinical follow-up is planed. A punch skin biopsy for fibroblast studies was collected at last FU.
Conclusion: ADCK3 ataxia should be considered as a differential diagnosis in writer‘s cramp and/or slowly progressive gait instability, especially if there is a childhood onset and positive family history.
Figure: Cerebellar atrophy and writer´s cramp associated dysgraphia in the male sib. (Videos of both affected patients will be presented).
Abstract 10 _ Expanding the phenotype of Pseudoxanthoma elasticum with hereditary spastic paraplegia
C.M. Durand (1), A. Legrand (2,3,4), A. Mesnil (2), S. Zuily (5), S. Adham (2,3), C. Tesson (6), X. Jeunemaitre (2,3,4), J.L; Boucher (7), N. Pietrancosta (7,8), C. Goizet (1) and J. Albuisson (2,3,4) 1 INSERM, U1211, Laboratoire Maladies Rares: Génétique et Métabolisme, Univ. Bordeaux, and Centre de Référence Neurogénétique, Bordeaux University Hospital, Bordeaux, France 2 Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Centre de Référence des Maladies Vasculaires Rares, Paris, France. 3 INSERM, U970, Paris Cardiovascular Research Centre, Paris, France. 4 Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France. 5 CHRU de Nancy, Regional Competence Centre for Rare Vascular and Systemic Autoimmune Diseases, Vascular Medicine Division, Nancy F-54000, France; Inserm, UMR_S 1116, Lorraine University, Nancy, France 6 Inserm U1127, CNRS UMR 7225, UPMC Paris 06 University, UMR S1127, Sorbonne University, Brain and Spinal Cord Institute (ICM), Hôpital de la Salpêtrière, Paris, France 7 UMR 8601 CNRS, University Paris Descartes, Paris Sorbonne Cité, Paris, France. 8. Team Chemistry & Biology, Modeling & Immunology for Therapy, CBMIT, 2MI Platform, Paris, France
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Background: Pseudoxanthoma elasticum (PXE) is an autosomal recessive disorder characterized by ectopic mineralization and fragmentation of the elastic fibers of connective tissues. ABCC6 has been the only identified gene, but up to 18% of cases remain genetically unsolved with one or no pathogenic variant in ABCC6. The corresponding negative French PXE cases were genetically explored for new PXE gene(s). Methods: Exome sequencing was performed in one ABCC6 negative PXE family with additional features, to search for pathogenic variants. We identified a candidate gene (CG) in a congruent metabolic pathway, and sequenced 46 additional ABCC6 negative PXE index cases (IC). An in vitro biochemical assay was carried out to determine the pathogenicity of identified missense variants and a clinical description of positive cases was performed to refine their phenotypic spectrum. Results: Out of 47 PXE IC, 3 harbored 2 pathogenic variants in our CG. Histologically-confirmed skin lesions, and diminished visual acuity due to maculopathy evoked the diagnosis of PXE. The association with neurological symptoms was strikingly present in the 3 cases, evoking a phenotype of PXE “plus” neurological symptoms. Biochemical analyses confirmed loss of activity of the corresponding mutated enzyme. Conclusion: Our CG is mutated in 6.4% of our unsolved PXE cases and should be systematically sequenced in suspected PXE cases with neurological findings: spastic paraplegia, dystonia, cognitive impairment, peripheral neuropathy and brain MRI abnormalities. The mechanism leading to overlapping phenotype for these 2 genes remains to be explored to explain their role and link in mineralization. Keywords: Hereditary spastic paraplegia, Pseudoxanthoma elasticum, Exome.
Abstract 11 _ How HSP Affects Patient Wellbeing
Adam Lawrence, CEng. Diagnosed with HSP in 2009.
Three on-line surveys were undertaken in 2016, 2017 and 2018 for people with HSP. 700 responses are reported in full on my HSP blog http://hspjourney.blogspot.co.uk/.
Respondents answered wellbeing questions to explore links between HSP factors and wellbeing.
In 2017 potentially significant wellbeing differentiators were identified:
• People without pain from HSP have a better wellbeing than those who get pain from HSP.
• People content with their employment/occupation have a better wellbeing than those not content.
• People whose employers are not supportive of HSP situations tend to have a lower wellbeing.
• Those who can walk as far as they want and those unable to walk have a better wellbeing.
In 2018 three symptoms showed significant negative wellbeing effects; depression, stress, and HSP affecting learning/memory. Three further symptoms showed potentially significant negative effects; poor co-ordination, regular falls, and back/hip pain.
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Several factors have large wellbeing effects, but many are not direct HSP symptoms. Help or treatment in these may result in improved wellbeing. Potential areas include;
• Decreasing: Depression, stress, anxiety, worries • Lifestyle or other changes to improve sleep • Reductions in pain • Strength/balance training to reduce falls • Activity/exercise to maintain mobility as long as possible
Additional findings:
• 90% with HSP have moderate or severe fatigue. • 80% with HSP typically get 'discomforting' or 'distressing' pain from HSP. • Walking is most affected with; steps/stairs, tiredness/fatigue, uneven ground, carrying. • Symptoms with greatest effect; fatigue, difficulty walking, loss of balance, muscles
feeling stiff, bladder problems, back/hip pain. • Longitudinally, not all symptoms persist from year to year.
Abstract 12 _ CONFIDENTIAL
Abstract 13 _ Action potential conduction deficits in a murine model of SCA38.
Eriola Hoxha (1,2), Ilaria Balbo (1,2), Roberto Spezzano (3), Roberta Parolisi (2), Francesco Ravera (1,2), Federica Genovese (1,2), Emilia Malvicini (1,2), Eleonora Di Gregorio (1), Alfredo Brusco (1), Nico Mitro (3), Donatella Caruso (3), Filippo Tempia (1,2). (1) University of Torino, Torino, Italy; (2) Neuroscience Institute Cavalieri Ottolenghi, Orbassano, Italy; (3) University of Milano, Milano, Italy.
SCA38 is due to mutation of the gene ELOngase of Very Long chain fatty acids type 5 (ELOVL5), the rate-limiting enzyme for the production of polyunsaturated fatty acids (PUFA) with more than 18 carbon atoms. Patients with SCA38 present with cerebellar atrophy, ataxia and impairment of both central and peripheral evoked potentials. Mice with a targeted deletion of Elovl5 recapitulate the main SCA38 symptoms, including ataxia and cerebellar hypotrophy. Aim of this study was to investigate action potential conduction in Elovl5-deficient mice. Conduction velocity was reduced in both peripheral and central axons. These results indicate that Elovl5 is required for fast action potential conduction in both peripheral and central nerve fibers. Action potential velocity relies on proper myelin sheaths. We analyzed the ultrastructure of myelin in Elovl5-deficient mice, finding an enlarged periodicity with reduced G-ratio across all axonal diameters. Moreover, the myelin MBP protein was less abundant in Elovl5-deficient fibers. Since Elovl5 is crucial to attain normal amounts of PUFA, which are the principal component of myelin, we performed a lipidomic analysis of peripheral nerves. Elovl5-deficient mice showed an unbalance between PUFA longer than 18 carbon atoms relative to shorter ones, with an increased ratio of saturated to unsaturated fatty acids. These results suggest that, in SCA38 patients, PUFA alterations might alter myelin structure, causing slower action potential conduction along axons. Cerebellar function is based on precise timing of neural signals. Therefore, action potential conduction deficits caused by myelin alterations might be responsible for cerebellar symptoms.
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Abstract 14 _ CONFIDENTIAL
Abstract 17 _ Biallelic Variants in the Nuclear Pore Complex Protein NUP93 Are Associated with Non-progressive Congenital Ataxia.
Zanni G1, De Magistris P2, Nardella M1, Bellacchio E3, Barresi S3, Sferra A1, Ciolfi A3, Motta M3, Lue H2, Moreno-Andres D2, Tartaglia M3, Bertini E1, Antonin W2. 1. Department of Neurosciences, Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesù Children's Hospital, IRCCS, 00146, Rome, Italy. 2. Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, 52074, Aachen, Germany. 3. Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCSS, Rome,
Nuclear pore complexes (NPCs) are the gateways of the nuclear envelope mediating transport between cytoplasm and nucleus. They form huge complexes of 125 MDa in vertebrates and consist of about 30 different nucleoporins present in multiple copies in each complex. Here, we describe pathogenic variants in the nucleoporin 93 (NUP93) associated with an autosomal recessive form of congenital ataxia. Two rare compound heterozygous variants of NUP93 were identified by whole exome sequencing in two brothers with isolated cerebellar atrophy: one missense variant (p.R537W) results in a protein which does not localize to NPCs and cannot functionally replace the wild type protein, whereas the variant (p.F699L) apparently supports NPC assembly. In addition to its recently described pathological role in steroid-resistant nephrotic syndrome, our work identifies NUP93 as a candidate gene for non-progressive congenital ataxia.
Abstract 18 _ Overview of a Norwegian database of hereditary spastic paraplegia and hereditary ataxias
Ann-Helen Richvoldsen 1, Iselin M. Wedding 2, Chantal M. E. Tallaksen2, Kaja K. Selmer 3,4, Jeanette A. Koht 2,5 Siri Lynne Rydning 2, 3
1 Department of Neurology, Telemark Hospital, Norway; 2 Department of Neurology, Oslo University Hospital, Norway; 3 Faculty of Medicine, University of Oslo, Norway; 4 Department Research and development, Clinic of Neuroscience, Oslo University Hospital, Norway 5 Department of Neurology, Vestre Viken Hospital Trust, Norway
We hereby present an updated overview of the patient material included in the research study “Hereditary ataxias and spastic paraplegias” in Norway. In 2008 the minimum prevalence of these disorders in southeast Norway was estimated to 14.9:100.000, and the proportion with molecular diagnosis was 25% (22/87) for hereditary cerebellar ataxia (HCA) and 37% (32/65) for HSP (Erichsen et al., Brain, 2009).
Of the 767 individuals currently included, 392 were classified as HSP and 375 as HCA. Of these, 48% had an exact genetic diagnosis, 61% in the HSP-group and 35% in the HCA-group. Grouping family members together, there were 522 probands (families or sporadic cases) of whom 41% had a genetic diagnosis.
The most common AD-HSPs were as SPG4 (60 probands), SPG3 (9) and SPG31 (6). The most common AR-HSP/HCA were Friedreich ataxia (27), SPG7 (11), ATX/HSP-POLR3A (10), SPG11 (7), and SPG5 (5). The repeat expansion SCA’s were not very frequent; five probands had SCA3, three SCA1 and two SCA2. Seven probands had X-linked disorders; X-ALD (3), SPG1 (2), SPG2 (1) or Fragile X tremor-ataxia syndrome (1). Of probands without genetic diagnosis, 23 showed AR inheritance pattern (5 HSP, 18 HCA), 92 showed a AD pattern (37
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HSP, 55 HCA), and 184 were classified as sporadic (73 HSP, 111 HCA). In total, there were 49 different genetic diagnoses.
The proportion of probands with HSP/HCA with molecular diagnosis is increasing and the diagnoses confirms overlapping genotypes and phenotypes.
Figure 1. Overview of the diagnoses in the Norwegian HSP/HCA database.
Figure legend: In total, 206 AD probands and 115 AR probands were registered. A-T = Ataxia-telangiectasia; F-ALS = familial ALS; FRDA = Friedreich ataxia. Other AD-HSP: SPG10 (3), AD-SPG30 (3). Other AD-HCA: EA2 (2, episodic ataxia 2), SCA1 (3), SCA6 (2), SCA21 (2), SCA11 (2), and with one proband each; AOA1, AOA2, SCA5, SCA42, OPA1, GLUT1DS, benign hereditary chorea, and CAPOS. Other AR-HSP: SPG 39 (2), SPG17 (1), SPG46 (1), SPG75 (1), and CMT4C (1), Other AR-HCA: SCAR16 (2), ARSACS (2), AVED (2), POLG (2), CoQ10D4 (2). Other HCA in the AR probands included disorders of glycosylation, immunodeficiency or gangliosidosis.
Abstract 19 _ Double trouble - SPG10 and 22q11.2 duplication syndrome in one family
Siri Lynne Rydning (1,2), Sjur Prestsæter (1), Iselin M. Wedding (2), Zafar Iqbal (2), Kaja K. Selmer (3), Chantal M. E. Tallaksen (2), Jeanette A. Koht (1,4)
(1) Institute of Clinical Medicine, University of Oslo, Norway; (2) Department of Neurology, Oslo University Hospital, Norway; (3) Department Research and development, Clinic of Neuroscience, Oslo University Hospital, Norway; (4) Department of Neurology, Vestre Viken Hospital Trust, Norway
Over the last decade there has been an exponential increase in knowledge of the genetic causes, phenotypic spectra, and overlapping forms of HSP. Sometimes, as this story shows, more than one monogenic disorder may be present in one family.
We describe a family where four generations had symptoms of HSP, compatible with a dominant inheritance pattern. The investigated family members had either pure HSP, complex HSP with cognitive signs, or mild cognitive signs without HSP. One patient with findings compatible with complex HSP also had childhood onset epilepsy and psychomotor delay, supposedly caused by febrile seizures in infancy. Age at onset of spasticity varied from from age 5 to 28. The severity varied from findings only at examination to walking aid dependency.
A broad genetic work-up including both gene panel sequencing for hereditary movement disorders and array comparative genomic hybridization was performed.
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Suprisingly, two different genetic variants were identified. A variant in KIF5A, c.751G>A (p.Glu251Lys), causing autosomal dominant SPG10 was present in the family members with spastic paraparesis. Also, a 22q11.21 duplication was present in two familiy members.
SPG10 can present both as pure and complex HSP, and may cause cognitive decline. The 22q11 duplication can be asymptomatic or cause mild symptoms, such as intellectual difficulties.
In this family, there appears to be several causes to the neurological phenotypes. SPG10 is the likely cause of spastic paraparesis, whereas the cause of mild cognitive difficulties might be both a complex form of SPG10 and the 22q11.2 duplication syndrome.
Figure 1: Pedigree of the family
Figure legend: Black = HSP phenotype. Grey = Cognitive signs and carriers of the 22q11.21 duplication. The KIF5A-variant c.751G>A (p.Glu251Lys) (NM_004984.2) was identified in patients II-2, III-2, IV-1 and IV-2. Patient II-2 had a pure HSP, patients III-2, IV-1 and IV-2 had complex HSP.
Abstract 20 _ A series of dominant heterozygous KIF1A mutations in different clinical and neuroradiological phenotypes
Yosra HALLEB (1), Lise LARRIEU (1), François RIVIER (2), Nicolas LEBOUCQ (3) Emilie CARME (2), Cyril GOIZET (4), Yves CHEVALIER (5), Claire GUISSART (1), Michel KOENIG (1)
(1) Laboratoire de génétique moléculaire, Montpellier, France (2) Service de neuropédiatrie, Hôpital Gui de Chauliac, Montpellier, France (3) Service de Neuroradiologie, CHU de Montpellier, Montpellier, France (4) Service de génétique médicale, Groupe hospitalier Pellegrin, Bordeaux, France (5) Service de neurologie, Hôpital de Montbéliard, France
The KIF1A gene encodes a motor protein involved in the fast-anterograde transport of synaptic-vesicle precursors along axon microtubules. KIF1A mutations have been described in a wide range of phenotypes in both recessive and dominant transmissions. Variants in the motor domain are incriminated in dominant and recessive forms of SPG30, dominant mental retardation type 9 (MRD9) and progressive encephalopathy.
In this study, we report 4 patients with different missense mutations of the kinesin motor (ATPase) domain of KIF1A. Four mutations were de novo, and one was identified in a family of 4 affected over 2 generations. While the familial case was associated with the
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dominant form of pure SPG30 with normal cognition, the de novo mutations were associated with additional signs, ranging from epileptic encephalopathy to mild epilepsy, and with abnormal MRI images, that included differently dysmorphic cerebellum and corpus callosum.
All mutations are predicted deleterious by the SIFT and PolyPhen2 prediction programs, and the affected residues are highly conserved among eukaryotes. One mutation is novel and two are located in the Walker B motif of the ATPase. When compared with previously reported missense mutations of this domain, no correlation between the site of mutation and the severity of clinical presentation emerged. Our results highlight the wide clinical spectrum associated with KIF1A mutations, which nevertheless cluster in a very small portion of the protein.
Abstract 21 _ Second heterozygous dominant STUB1 mutation reported responsible for a new SCA48
Yosra HALLEB (1), Lise LARRIEU (1), Fabienne ORY-MAGNE (2), Claire GUISSART (1), Michel KOENIG (1)
(6) Laboratoire de génétique moléculaire, Montpellier, France (7) Service de neurologie Générale, Hôpital Pierre-Paul Riquet, Toulouse, France
STUB1 codes for a protein that participates in protein quality control by targeting a broad range of chaperone protein substrates for ubiquitin-dependent degradation.
Compound heterozygous and homozygous mutations of STUB1 (STIP1 homologous and Ubox-containing protein 1) are associated with recessive SCA (SCAR16). A frameshift heterozygous STUB1 mutation was recently reported in a very large family segregating a new form of dominant spinocerebellar ataxia (SCA48) characterized by early cerebellar cognitive-affective syndrome and late-onset SCA (Genis D. et al. 2018).
We report a patient who presents since the age of 32 years, a progressive cerebellar syndrome with cognitive impairment and myoclonic and dystonic movements. He also has a history of depressive syndrome. His brain MRI shows atrophy of the cerebellum and the superior cerebellar peduncles. His mother presented with a progressive behavioural disorder, cognitive impairment, ataxia, pontomesencephalic and cerebellar atrophy on MRI. His maternal grandmother and uncle also have cognitive symptoms. Genetic analysis of the patient revealed the presence of a heterozygous STUB1 missense mutation, p.Cys232Gly, that is absent from the gnomAD database. Residue Cys232 is conserved in almost every eukaryote and is located in the C-terminal U-Box domain, which is required for the ubiquitin protein ligase activity. The change of Cysteine 232 into Glycine is predicted pathogenic (SIFT Score = 0.00; PolyPhen2 Score 1.00). The previously reported dominant STUB1 mutation truncates the protein also in the U-Box domain, 43 residues downstream from Cys232. It is conceivable that either a mutated or a C-terminally truncated U-Box domain confers a dominant gain of function or a dominant negative function, that may account for the unusual observed mode of inheritance.
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Abstract 22 _ WES confirms implication of VPS13D in spastic ataxia determinism
C.M. Durand (1,2), V. Michaud (3), C. Angelini (3), I. Coupry (1), C. Goizet (1,2), A. Trimouille (1,3) (1) Laboratoire MRGM, INSERM U1211, Université Bordeaux, Bordeaux, France (2) Centre de Référence Neurogénétique, Service de Génétique Médicale, CHU Bordeaux, Bordeaux, France. (3) Laboratoire de Génétique Moléculaire, Service de Génétique Médicale, CHU Bordeaux, Bordeaux, France.
Background:. Hereditary spastic paraplegias (HSPs) are characterized by progressive spasticity of the lower limbs. Recently, biallelic VPS13D mutations have been reported in patients presenting ataxia, spastic paraplegia or childhood onset movement disorder. Here, we report a novel patient with spastic ataxia related to VPS13D. Patient report: The patient, with negative family history, presented progressive ataxia since age 7 years. He progressively lost the ability to walk, he walked with a stick at 19 years and he used a wheelchair since 26 years. He complained of memory and attention deficit at 22 years old, which has been confirmed by neuro-psychological examination. At age 45, the patient had moderate cerebellar ataxia associated with severe spasticity, muscle weakness and amyotrophy of the lower limbs. MRI showed cerebellar atrophy mainly on the vermis and atrophic spinal cord. Genetic results: Whole‐exome sequencing let to identify compound heterozygous variants in VPS13D: c.946C>T, p.Arg316* and c.12416C>T, p.Ala4139Val. This later variant was predicted deleterious by in silico tools. No other pathogenic or likely pathogenic variants in known disease were identified. Functional studies: The analysis of mitochondrial network organization by fluorescence microscopy in skin fibroblasts showed fragmented mitochondria as previously described. Western blot analysis revealed a drastic reduction of mitochondrial complexes suggesting an alteration of mitochondrial function. Conclusion: Functional results support the pathogenicity of the missense variant and thus this patient confirms the existence of VPS13D-related spastic ataxia
Abstract 23 _ KCNJ10 mutations causing a mild phenotype in 2 consanguineous families
Lise LARRIEU (1), Yosra HALLEB (1), Alain VERLOES (2), Claire EWENCZYK (3), Claire GUISSART (1), Michel KOENIG (1) (1) Molecular Genetics Laboratory, Montpellier University Hospital, France (2) Department of Clinical Genetics, Robert Debre Hospital, Paris, France (3) Genetics Department, Pitié-Salpêtrière Hospital, Paris, France
KCNJ10 gene mutations cause an autosomal recessive condition called EAST/SESAME syndrome characterized by seizures, sensorineural deafness, ataxia, mental retardation and electrolyte imbalance. It is a rare and multisystemic disorder, for which the spectrum of disease presentation has not yet been fully explored. In this work we report 2 families with KCNJ10 mutations with particular clinical phenotypes. In family 1, the patient and his sister have spastic ataxia, seizures and psychomotor retardation, starting during the first year of life (current age : 22 and 13 years). No hearing problem was reported. In family 2, the patient has seizures since age 13 and spastic ataxia since age 20. Her brother has a milder phenotype with seizures
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from age 1 to 30, dysarthria starting at 25 years and ataxia at 30 years. Biochemical assays, auditory evoked potentials and induced otoacoustic emissions were investigated for the index patient of family 2 and were normal. In the first family, we identified the previously reported p.Arg65Cys mutation in homozygosity in the 2 siblings. In the second family, the 2 siblings were homozygous for the new p.Ile209Thr mutation. Both mutations are predicted pathogenic by the SIFT and PolyPhen2 programs and were found in heterozygosity in the parents of the two families. The mild clinical presentation related to these two missense mutations is presumably explained by residual activity of the mutant Kir4.1 inwardly rectifying potassium channel, therefore leading to less severe consequences. Our results reveal a new phenotype related to KCNJ10 mutations defined by spastic ataxia, epilepsy and absence of deafness and electrolyte imbalance.
Abstract 24 _ Defective autophagy in CAPN1 mutated patients with hereditary spastic paraparesis type 76
Chiara Vantaggiato1, Elena Panzeri1, Andrea Citterio1, Massimiliano Filosto 2, Filippo M. Santorelli3, Maria Teresa Bassi1. 1Scientific Institute, IRCCS E. Medea, Laboratory of Molecular Biology, Bosisio Parini, Lecco, Italy 2Center for Neuromuscular Diseases, Unit of Neurology, ASST Spedali Civili and University of Brescia, Brescia, Italy 3 Unit of Molecular Medicine, IRCCS Foundation Stella Maris, Pisa, Italy
CAPN1 has been identified as a causative gene for spastic paraplegia 76 (SPG76), a complicated form of HSP. The encoded protein, calpain1, is a calcium-activated intracellular cysteine protease that catalyzes the proteolytic cleavage of a variety of cellular proteins and is involved in a wide range of biological processes. Among the others, calpain1 controls the levels of autophagy in living cells under nutrient-rich conditions. In particular, calcium-activated calpain1 proteolyzes ATG5, preventing the formation of the ATG5-ATG12 complex and the formation of autophagosomes. We therefore analyzed autophagy in fibroblast cells derived from CAPN1 patients carrying a point mutation (p.T320LfsX) that lead to the absence of the protein. We found that CAPN1 mutated cells presented increased levels of the ATG5-ATG12 complex compared with control and the accumulation of autophagosomes in the cytosol, due to increased autophagosome formation. Moreover mutated cells showed high mTor, Akt and
GSK3(Ser9) phosphorylation levels, that also trigger autophagy. More in depth the characterization of the autophagy defect is undergoing. This data indicate SPG76 as an additional form of HSP associated to autophagy defects, as yet reported for SPG11, SPG15 and SPG49, thereby widening the set of HSP subtypes that could benefit from the identification of autophagic process targets for therapeutic intervention.
Abstract 25 _ ATXN1, ATXN2, and TBP intermediate allele frequency is 3.7% in the Italian healthy subjects unrelated to SCA families
Lorenzo Nanetti (1), Alessia Mongelli (1), Elena Salvatore (2), Elena Rizzo (1), Franco Taroni (1), Cinzia Gellera (1), Caterina Mariotti (1).
1) Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy 2) Department of Neurosciences, Reproductive and Odontostomatological Sciences, "Federico II" University, Naples, Italy.
Spinocerebellar Ataxia type 1-2-17 (SCA1-2-17) are adult-onset autosomal dominant diseases, caused by CAG triplet pathological expansions. In this study, ATXN1, ATXN2, and TBP genes were analyzed in a large cohort of individuals, not presenting neurological
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phenotypes or family history for autosomal dominant neurodegenerative diseases, at two referral Centers for Neurogenetic Diseases in Milan and Naples. A neurological examination and brain MRI was proposed to all intermediate allele carriers. 729 individuals were enrolled in the study (mean age was 55.3 ± 12.6 years and 45.7% were men). Fully penetrant alleles were not identified within the three genes. Reduced penetrance alleles were identified in 7 individuals (0.96%). A women aged 49 carried 33 CAG in the ATXN2 gene, and 6 individuals carried reduced penetrant alleles in the TBP gene: 4 individuals, aged 30, 35, 64, and 67, carried 42 CAG; 1 women, aged 66, carried 43 CAG; a man aged 66 carried 44 CAG. Five subjects accepted to perform clinical and MRI evaluation, all presenting unremarkable neurological and brain MRI findings. ATXN2 meiotic instability alleles were identified in 20 individuals (2.7%). SFaNI analyses demonstrated that the 3 ATXN1 alleles carrying 35-36 CAG were all CAT interrupted, and that 7.1% of subjects carried normal length (mean 28 CAG, range 25-32) uninterrupted pure CAG stretches in the ATXN1 gene. In conclusion, 27 subjects (3.7%) were demonstrated to carry an intermediate allele in one of the three genes, being at risk for a late-onset neurodegenerative disease or to transmit an unstable CAG expansion to the offspring.
Abstract 26 _ CONFIDENTIAL
Abstract 28 _ SCA1-specific phenotypes in patient-derived neurons
R.A.M. Buijsen 1, M. Sáez González 1, L.M. van der Graaf 1, W.M.C. van Roon-Mom 1
1 Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
Introduction Spinocerebellar ataxia type 1 (SCA1) is a hereditary neurodegenerative disease caused by a polyglutamine expansion in the ataxin-1 protein (Orr, Chung et al. 1993) that results in aberrant protein aggregation and neuropathology, mainly in the cerebellum (Seidel, Siswanto et al. 2012). Furthermore, it has been shown that the ataxin-1 protein plays a role in neurodevelopment (Edamakanti, Do et al. 2018) and the regulation of bioenergetics and metabolic alterations in the cerebellum of SCA1 mouse models (Sanchez, Balague et al. 2016). The aim of our study is to (1) generate patient-specific models and (2) determine a SCA1-specific phenotype in these models. Methods Skin biopsies were obtained from four SCA1 patients and four related healthy controls and human induced Pluripotent Stem Cell (hiPSC) lines were generated using the integration-free Sendai virus based method (Buijsen, Gardiner et al. 2018). The presence of aggregates was assessed using immunohistochemistry while dendritic length and number of branching points were evaluated after transient GFP transfection. Finally, the two major energy pathways of the cell, mitochondrial respiration and glycolysis, were measured using the Seahorse XF96 Extracellular Flux Analyzer where oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) respectively were used as outcome measures.
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Results We successfully generated patient-derived fibroblast and hiPSC lines. After differentiation of the SCA1 hiPSCs into neuronal cells, ataxin-1 positive aggregates were present. Furthermore, after GFP transfection there was a reduction in cell branching en branch-length indicating neurodevelopmental delay. A deficit in bioenergetics was shown by a decreased in maximal respiration and increased glycolysis in patient-derived cells compared to control cells, supporting a role for mitochondrial dysfunction in SCA1 pathogenesis. Conclusion
We have generated an hiPSC‐based model for SCA1 that recapitulates key pathological
features of this disease. Moreover, our hiPSC‐based model provides a valuable tool to investigate the pathogenic mechanisms of SCA1 and to screen for drugs that may prevent or rescue neurodegeneration in SCA1. Buijsen, R. A. M., S. L. Gardiner, M. J. Bouma, L. M. van der Graaf, M. W. Boogaard, B. A. Pepers, B. Eussen, A. de Klein, C. Freund and W. M. C. van Roon-Mom (2018). "Generation of 3 spinocerebellar ataxia type 1 (SCA1) patient-derived induced pluripotent stem cell lines LUMCi002-A, B, and C and 2 unaffected sibling control induced pluripotent stem cell lines LUMCi003-A and B." Stem Cell Res 29: 125-128. Edamakanti, C. R., J. Do, A. Didonna, M. Martina and P. Opal (2018). "Mutant ataxin1 disrupts cerebellar development in spinocerebellar ataxia type 1." J Clin Invest 128(6): 2252-2265. Orr, H. T., M. Y. Chung, S. Banfi, T. J. Kwiatkowski, Jr., A. Servadio, A. L. Beaudet, A. E. McCall, L. A. Duvick, L. P. Ranum and H. Y. Zoghbi (1993). "Expansion of an unstable trinucleotide CAG repeat in spinocerebellar ataxia type 1." Nat Genet 4(3): 221-226. Sanchez, I., E. Balague and A. Matilla-Duenas (2016). "Ataxin-1 regulates the cerebellar bioenergetics proteome through the GSK3beta-mTOR pathway which is altered in Spinocerebellar ataxia type 1 (SCA1)." Hum Mol Genet 25(18): 4021-4040. Seidel, K., S. Siswanto, E. R. Brunt, W. den Dunnen, H. W. Korf and U. Rub (2012). "Brain pathology of spinocerebellar ataxias." Acta Neuropathol 124(1): 1-21.
Abstract 29 _ A simple method for (ATTTC)n detection in SCA37 suitable for other repeat diseases
Joana Rocha Loureiro (1,2), Cláudia Louro Oliveira (1,2), Jorge Sequeiros (2,3), Isabel Silveira (1,2). (1) Genetics of Cognitive Dysfunction Laboratory, i3S-Instituto de Investigação e Inovação em Saúde; (2) IBMC- Institute for Molecular and Cell Biology; (3) UnIGENe, i3S-Instituto de Investigação e Inovação em Saúde; Universidade do Porto, Porto, Portugal
Spinocerebellar ataxia type 37 (SCA37) is caused by an (ATTTC)n insertion in the middle of a polymorphic ATTTT repeat in the non-coding region of DAB1. The non-pathogenic alleles have a configuration [(ATTTT)7–400], whereas pathogenic alleles have a complex structure of [(ATTTT)60–79(ATTTC)31–75(ATTTT)58–90]. Since the discovery of the DAB1 repeat insertion, other similar non-coding repeats have been identified in SMAD12, TNRC6A and RAPGEF2 in families affected with benign adult familial myoclonic epilepsy (BAFME) types 1, 6 and 7. The molecular diagnosis of these diseases is laborious because large (ATTTT)n non-pathogenic alleles can be found in non-affected individuals. Previously, we have suggested a workflow for the SCA37 diagnosis combining standard PCR with a specific ATTTT repeat-primed PCR that allows fast detection of large pentanucleotide alleles minimizing the number of samples that require long-range PCR and Sanger sequencing. However, sequencing of this repetitive region is technically challenging. In this work, we aimed to further simplify the (ATTTC)n detection using a restriction enzyme that specifically recognizes the ATTTC motif. To determine the presence or absence of an (ATTTC)n insertion in large alleles, we performed long-range PCR followed by enzymatic restriction of the PCR products. Analysis of the restriction products by agarose gel electrophoresis showed that contrarily to the ATTTT the ATTTC motif was recognized and enzymatically digested. This assay allows a rapid and inexpensive detection
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of SCA37 pathogenic alleles and can be extended to other neurological diseases caused by expansion of similar ATTTCATTTC repeats such as BAFME1, 6 and 7.
Abstract 30 _ Brain tissue co-expression network analysis exposes relationship between ataxia, dystonia and depression
Miaozhen Huang(1), Marina AJ de Koning-Tijssen(2), D.S. Verbeek (1)
(1)University of Groningen, University Medical Center Groningen, Department of Genetics, Groningen, The Netherlands (2)University of Groningen, University Medical Center Groningen, Department of Neurology, Groningen, The Netherlands
N= 250
Ataxia and dystonia are movement disorders that often co-occur and are linked with dysfunction of the cerebello-thalamo-cortico circuit. Comorbid depression is common in ataxia and dystonia, but its association with the pathogenesis of these movement disorders is not fully understood. Here, we aim to explore the genetic relationship between depression and ataxia and dystonia in brain regions of the cerebello-thalamo-cortico circuit.
We used 163 Human Phenotype Ontology genes shared between ataxia and dystonia (A&D genes) and 497 GWAS depression genes. Using Genotype-Tissue Expression data, we identified that many A&D genes and GWAS depression genes were highly expressed in the cerebellum compared to other brain regions. These genes were significantly enriched for the pathways mitochondrial respiration complex assembly and nervous system development, respectively. For genes lowly expressed in cerebellum, we identified cellular respiration and regulation of biological quality and modulation of chemical synaptic transmission as major themes.
Further, we constructed gene set-specific and cerebellum, cortex, and basal ganglia-specific gene co-expression networks. From these networks, 17 shared pathways linked to ataxia, dystonia and depression were identified which were all related to synaptic transmission, synaptic signaling and nervous system development. In the 17 pathways of the cerebellar co-expression network of A&D genes, four GWAS depression genes were present that showed high expression during embryonic cerebellum development.
Based on our results, we propose that the cerebellum, in addition to regulation of motor coordination and motor function, plays a role in mood processing and that a developmental predisposition underlies depression in ataxia and dystonia cases.
Abstract 31 _ An unstable ATTTC repeat mutation within the Disabled 1 gene causes cerebellar Purkinje cell alterations, DAB1 RNA switch, and Reelin signalling dysregulation in Spinocerebellar ataxia type 37. Marc Corral-Juan,1 Daniel Cota-González,1 Alberto Rábano,2 Victor Volpini,3 Ramiro Alvarez- Ramo,4 Ivelisse Sánchez,1 Antoni Matilla-Dueñas,1*. 1. Functional and Translational Neurogenetics Unit, Department of Neuroscience, Health Sciences Research Institute Germans Trias i Pujol (IGTP), Can Ruti Campus, Badalona, Barcelona, Spain. 2. Fundación CIEN, Madrid, Spain. 3. IDIBELL, L’Hospitalet, Barcelona, Spain. 4. Neurodegeneration Unit, Neurology Service, Department of Neuroscience, University Hospital Germans Trias i Pujol (HUGTiP), Can Ruti Campus, Badalona, Barcelona, Spain.
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We first described the spinocerebellar ataxia type 37 (SCA37) as a dominantly inherited pure cerebellar ataxia of late onset characterised by early dysarthria and altered vertical eye movements. More recently, we proved that the unstable intronic ATTTC repeat mutation within the 5’-noncoding regulatory region of the gene encoding the reelin adaptor protein DAB1 as the causative defect in 35 patients from six Spanish SCA37 families all from the south of Spain. We demonstrate a significant inverse correlation between ATTTC insertion size and the age of onset in males, but not in females. Moreover, affected females presented at a significantly younger age of onset in our cohort of patients. SCA37 patients present with ATTTC repeat size ranging from 46 to 71, and the ages of onset between 25 and 64 years old. Neuropathology in two SCA37 patients revealed severe loss of Purkinje cells (PCs) with abundant astrogliosis, empty baskets, occasional axonal spheroids, and hypertrophic fibers by phosphorylated neurofilament immunostaining in the cerebellar cortex. The remaining PCs showed loss of calbindin immunoreactivity, aberrant dendrite arborisation, nuclear pathology, and multiple ubiquitinated perisomatic granules immunostained for DAB1. Importantly, we demonstrate that the ATTTC repeat mutation dysregulates DAB1 expression and induces a DAB1 RNA switch resulting in the overexpression of a specific transcript in the cerebellum (MK015668) and the up-regulation of the Reelin-DAB1 and PI3K/AKT signalling in the SCA37 cerebellum. Our study demonstrates that the unstable ATTTC pentanucleotide repeat mutation within the DAB1 gene dysregulates cerebellar Reelin- DAB1 signalling in the spinocerebellar ataxia type 37.
Abstract 32 _ POLR3A-related spastic ataxia: clinical-genotype correlation and identification of a novel large 3-exon deletion mutation in 3 unrelated Spanish families. Corral-Juan M1, Farré-Ribas X1, Serrano-Cárdenas KM2, Marco de Lucas E3, Berciano J2, Sánchez I1, Infante J2, Matilla-Dueñas A1. 1 Functional and Translational Neurogenetics Unit. Department of Neuroscience. Germans Trias i Pujol Research Institute (IGTP), Universitat Autònoma de Barcelona- Can Ruti Campus, Badalona, Barcelona, Spain. 2 Neurology Service. University Hospital Marqués de Valdecilla and Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED). IDIVAL. University of Cantabria (UC). Santander, Spain. 3 Radiology Department, Neuroradiology Section. University Hospital Marqués de Valdecilla, Santander, Spain.
POLR3-related disorders comprise a number of clinically overlapping disease entities including POLR3A related hereditary ataxia and spasticity. Recently, a novel and milder phenotype consisting of adolescent-onset spastic ataxia was proposed to be caused by an intronic mutation (c.1909+22G>A) in compound heterozygosity with missense and small nonsense mutations within the POLR3A gene. In this study, we aimed to further extend the clinical and genetic correlations associated with the POLR3A-spastic ataxia phenotype. Four affected patients from three unrelated Spanish families presenting with clinical spastic ataxia were candidates to present POLR3A mutations were included. NGS sequencing was performed with a custom targeted panel containing 187 related ataxia and spastic paraplegia genes on an Illumina HiSeq 2500 sequencer. Our custom pipeline Variant-Swepper bioinformatic algorithm was implemented for data analysis. CytoScan Xon microarray assay was used to identify exon deletions in candidate genes. Deletion breakpoints were characterised by PCR along with Miseq and Sanger sequencing. All four affected patients presented the c.1909+22G>A mutation in compound heterozygosity with a novel 3-exon deletion (c.646-687_1185+844del) in POLR3A. The phenotype combined
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variable cerebellar ataxia, gait and lower limb spasticity, involvement of central sensory tracts and tremor with MRI hyperintensities, as previously reported. Distinctly, we identified genu recurvatum in all patients and distal lower-limb acrocyanosis in three of them as signs not previously reported in POLR3A-related phenotypes. In conclusion, our study identified a novel large 3-exon deletion mutation in the POLR3A gene with genu recurvatum and distal lower-limb acrocyanosis as distinctive signs not previously described in POLR3A-related spastic ataxia phenotypes.
Abstract 34 _ Spastic ataxia and cerebellar features in a cohort of 59 adult patients with adult genetic leukoencephalopathies Roberta La Piana (1,2), Karine Choquet (2,3), Chelsea Smith (2), Paul Steven Giacomini (4), Yves Lapierre (4), Jack Antel (4), Donatella Tampieri (5), Bernard Brais (2). (1) Department of Neuroradiology, Montreal Neurological Institute, McGill University, Montreal, QC, Canada; (2) Laboratory of Neurogenetics of Motion, Montreal Neurological Institute, McGill University, Montreal, QC, Canada; (3) Harvard Medical School, Boston, USA; (4) Department of Neurology, Multiple Sclerosis Unit, Montreal, Neurological Institute, McGill University, Montreal, QC, Canada; (5) Queen’s University, Kingston, ON, Canada.
Introduction White matter abnormalities are documented in several forms of spastic ataxias and genetic cerebellar ataxias such as SPG11 and SPG35. Our goals were: a) to select subjects with spastic ataxia or predominant cerebellar features from our cohort of patients with genetic leukoencephalopathies, and b) to characterize their clinical and neuroradiological findings, as well as their genetic basis. Methods Since 2013, we have recruited 59 adult patients with suspected genetic leukoencephalopathy referred to our specialized white matter disease multidisciplinary team at the Montreal Neurological Institute. We assessed them with an integrated approach combining clinical phenotyping, advanced MRI imaging analysis and gene panel and whole exome next generation sequencing. Results We identified 27 subjects (27/59; 45.8% of our cohort) presenting with spastic ataxia (10) or cerebellar features without pyramidal signs (17). White matter abnormalities were multifocal in ten subjects and confluent in ten; signal changes were predominant in the posterior fossa in seven subjects. Nine individuals presented a various degree of cerebellar atrophy. We uncovered causal mutations in 4 subjects (4/27; 14.8%) in the FA2H, ITPR1, GALC, PEX16 genes and identified variants of unknown significance or candidate genes in 9 (9/27; 33.3%). Conclusions White matter changes are a common finding in complex ataxias and spastic ataxias as observed in 45.8% of our cohort. Though white matter changes may help in the diagnosis of some forms, our data support the high degree of genetic heterogeneity and indicate that there are still many genes to be uncovered for spastic ataxias associated with leukoencephalopathy.
Abstract 35 _ Age of symptoms onset is a major determinant of intrinsic functional brain architecture in Friedreich ataxia Naeije G1,2, Wens V1,3, Coquelet N1, Sjøgård M1, Serge Goldman1,3, Pandolfo M2, De Tiège X1,3
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1Laboratoire de Cartographie fonctionnelle du Cerveau, ULB Neuroscience Institute (UNI), Université libre de Bruxelles (ULB), Brussels, Belgium. 2Department of Neurology, CUB Hôpital Erasme, Université libre de Bruxelles (ULB), Brussels, Belgium. 3Department of Functional Neuroimaging, Service of Nuclear Medicine, CUB Hôpital Erasme, Université libre de Bruxelles (ULB), Brussels, Belgium.
Background: Friedreich ataxia (FRDA) is the commonest hereditary ataxia in Caucasians. Most patients are homozygous for expanded GAA triplet repeats in the first intron of the frataxin (FXN) gene, involved in mitochondrial iron metabolism. Here, we used magnetoencephalography (MEG) to characterize the main determinants of FRDA-related changes in intrinsic functional brain architecture.
Methods: Five minutes of MEG signals were recorded at rest from 18 right-handed FRDA patients (mean age 27 yrs, 9 females; mean SARA score: 21.4) and matched healthy individuals. The MEG connectome was estimated as resting state functional connectivity (rsFC) matrices involving thirty-seven nodes from six major resting-state networks and the cerebellum. Source-level rsFC maps were computed using leakage-corrected broad-band (3-40 Hz) envelope correlations. Post-hoc median-split was used to contrast rsFC in FRDA patients with different clinical characteristics. Non-parametric permutations and Pearson rank correlation test were used for statistics.
Results: High correlation rank indexes were found between rsFC and age of symptoms onset in FRDA mostly between the ventral attention, the default mode and the cerebellar networks; patients with higher rsFC developing symptoms at older age. Increased rsFC was found in FRDA with later age of symptoms onset compared to healthy subjects. No correlations were found between rsFC and other clinical parameters.
Conclusion: Age of symptoms onset is a major determinant of FRDA patients' intrinsic functional brain architecture. Higher rsFC in FRDA patients with later age of symptoms onset supports compensatory mechanisms for FRDA-related neural network dysfunction and position neuromagnetic rsFC as potential marker of FRDA neural reserve.
Abstract 36 _ Electrophysiological evidence for limited progression of the proprioceptive loss in Friedreich ataxia Naeije G 1,2, Bourguignon M1, Wens V1,3, Goldman S1,3, Pandolfo M1,3, and De Tiège X1,3.
1Laboratoire de Cartographie fonctionnelle du Cerveau, ULB-Neuroscience Institute (UNI), Université libre de Bruxelles (ULB), Brussels, Belgium
2Neurology Department, CUB Hôpital Erasme, Université libre de Bruxelles, Brussels, Belgium 3Department of Functional Neuroimaging, Service of Nuclear Medicine, CUB Hôpital Erasme, Université libre de Bruxelles, Brussels, Belgium
Aim:
To assess the developmental vs progressive impairment of proprioceptive pathways in Friedreich ataxia (FRDA) with a longitudinal study of the cortico-kinematic coherence (CKC) that reflects proprioceptive tracts integrity.
Method:
CKC was evaluated for active (aCKC; n=15) and passive (pCKC; n=16) right forefinger flexion–extensions movements using magnetoencephalography in 16 FRDA patients (10 females, mean age: 27±14y, mean SARA score: 21,15±8,72, mean GAA1: 698±203) in two sessions
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performed at about one-year interval (mean 13.25±4 months). CKC maps were computed at group-level and differences in group-level aCKC and pCKC between sessions were evaluated with nonparametric permutation test. Movement frequency and regularity in aCKC, and the Scale for the Assessment and Rating of ataxia (SARA) scores between the two sessions were compared using T-test.
Results:
SARA score significantly deteriorated at one-year (21±8,7 vs 22,9±8,3; p = 0,0063). Movement frequency and regularity in aCKC remained stable (respectively 1,87 Hz ± 0,61 vs 1,92 Hz ± 0,63; p=0,78 and 0,44±0,06 vs 0,46±0,08; p = 0,58). At group level, at one-year no significant difference in CKC values was found at movement frequency (F0) and first harmonic (F1) both for aCKC (F0: 0,08 vs 0,07; p = 0.4 F1: 0,04 vs 0,05; p = 0,69) and pCKC (F0: 0,08 vs 0,05; p = 0,08 F1: 0,05 vs 0,03; p = 0,39).
Conclusion:
No changes in CKC values was observed at one-year follow-up of FRDA patients, while the SARA score significantly worsened suggesting that cerebellar dysfunction is mostly responsible for ataxia progression in FRDA, while proprioceptive loss appears to be stable.
Abstract 37 _ CONFIDENTIAL
Abstract 39 _ CONFIDENTIAL
Abstract 40 _ De novo dominant TFG variant causes complex hereditary spastic parapaplegia type 57 Simona Petrucci 1,2,3, Fabrizia Stregapede4,5, Gina Ferrazzano 6, Aldo Germani1,2, Maria Piane1,2, Maria Rosaria Torrisi1,2, Francesco Nicita4, Enrico Bertini4, Giovanni Fabbrini6,7, Lorena Travaglini4. 1 Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy; 2 S. Andrea University Hospital, Rome, Italy; 3 Division of Medical Genetics , IRCCS-Casa Sollievo della Sofferenza , San Giovanni Rotondo, Italy; 4 Unit of Muscular and Neurodegenerative Disorders, Ospedale Pediatrico Bambino Gesù, Polo di Ricerca S. Paolo, Rome, Italy; 5 Department of Sciences, Roma Tre University, Rome, Italy; 6 Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy; 7 Neuromed Institute IRCCS, Pozzilli, Italy.
The tropomyosin-receptor kinase fused gene (TFG, NM_006070), encoding a protein involved in the regulation of vesicular trafficking between endoplasmic reticulum and Golgi apparatus, has recently been identified as a causative gene for dominant hereditary sensory-motor neuropathy and a recessive form of complex hereditary spastic paraplegia (HSP) (i.e., SPG57). SPG57 is characterized by early-onset spastic paraplegia, optic atrophy, and polyneuropathy. We describe the first SPG57 patient harboring a dominant TFG mutation. In this 30-year-old man a childhood-onset spastic paraplegia was complicated, during years, by optic atrophy and mild cognitive impairment. Full neurological instrumental investigations were unremarkable. A deep-sequencing NGS targeted panel of 113 HSP-related genes, identified a novel de novo heterozygous missense variant c.80A>G (p.H27R) in TFG. This variant was predicted to be damaging by several bioinformatics tools (e.g., SIFT, Provean). Since all the few reported SPG57 patients have an autosomal recessive inheritance, a supposed
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quantitative alteration in the other TFG allele was investigated by qRT-PCR assay. The dosage analysis of all exons and 5′-UTR of TFG excluded deletions and/or duplications of one or more exons. Moreover, the RT-PCR analysis of the full-length cDNA failed to detect alternative splicing isoforms possibly caused by a deep intronic mutation on the other allele. Although functional studies are needed to confirm the pathogenic effect of the H27R mutant protein, this novel variant is likely to be the unique cause of the phenotype of our patient. We hypothesize that both heterozygous and recessive TFG mutations cause SPG57, as rarely described for other types of HSP.
Figure 1. Sanger sequencing of TFG from genomic DNA, showing the heterozygous c.80A>G substitution in the
proband but not in his patents (A). Molecular analysis on cDNA that confirms the presence of the heterozygous mutation (Sanger sequencing, B), excludes both exonic deletions/ duplications (quantitative Real Time, C) and rules out deep intronic splice site alterations (agarose electophoresis of TFG full length cDNA, D).
Abstract 41 _ SPG8: clinical data and follow-up of a series of 34 patients Cecilia Marelli (1), Guillaume Banneau (2), Claire Guissart (3), Lise Larrieu (3), Cyril Goizet (4), Patrick Collignon (5), Jean Pouget (6), Christel Thauvin-Robinet (7), Pierre Labauge (1), Giovanni Stevanin (8), Michel Koenig (3), Alexandra Durr (8), and the collaborators of the SPATAX network: JP Azulay, A. Brice, JP Camdessanché, G. Carelli, G. Castelnovo, P. Charles, E. Delmont, S. Fenu, F. Mochel, S Moutton, K. Nguyen, V. Plante-Bordeneuve, F. Sedel, G. Taieb, C. Tallaksen.
(1) Department of Neurology, Gui de Chauliac University Hospital, Montpellier, France (2) APHP, Genetic Department, Pitié-Salpêtrière University Hospital, Paris, France (3) Laboratoire de Génétique Moléculaire, IURC, CHRU de Montpellier, Montpellier, France; Equipe Accueil EA7402, Université Montpellier, Montpellier, France; (4) CHU Bordeaux, Service de Génétique Médicale, Bordeaux, France; Laboratoire MRGM, INSERM U1211, Univ. Bordeaux, Bordeaux, France: (5) Service de Génétique Médicale, CHI Toulon, Toulon, France; (6) APHM, Hôpital Timone, Centre de Référence des maladies neuromusculaires et de la SLA, Marseille, France; (7) Inserm UMR 1231 GAD, Genetics of Developmental disorders and Centre de Référence Maladies Rares Anomalies du Développement et syndromes malformatifs FHU TRANSLAD, Université de Bourgogne-Franche Comté, Dijon, France. (8) Sorbonne Université, Institut du Cerveau et de la Moelle épinière (ICM), AP-HP, Inserm, CNRS, University Hospital Pitié-Salpêtrière, Paris, France
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Introduction: SPG8 is a rare dominant HSP caused by mutations in KIAA0196, encoding for the protein strumpellin.
Objective: to present the clinical and genetic features of a large series of SPG8 patients.
Methods: a retrospective collection from the Neurogenetic centers of Paris and Montpellier.
Results: there were 34 patients with SPG8 (11 families; 7 sporadic cases); one more patient finally had a VUS (p.Iso106Val). The mean age at onset was 40 ± 10 years; the symptoms at onset were: leg stiffness (n= 23), unsteadiness (n= 3), cramps (n= 2), and limb pain (n= 1). A pure HSP was found in 13 patients, while 18 had complex HSP with LL superficial sensory loss (n=8), UL and LL ataxia (n=6) with cerebellar ocular alterations (n= 7), dysarthria (n=4), swallowing difficulties (n=3), cognitive alteration (n=4), and UL weakness (n=3) and/or amyotrophy (n= 3). The EMG showed an axonal neuropathy only in 2/8, while a central SSEP alteration was found in 3/6 patients. The mean follow up duration was 16 ± 12 years. All the patients with a disease duration > 10 years (n=16) had a disability score (DS) ≥ 3 (=unable to run, limited walking without aid); after 15 years 10/13 patients at least required one stick to walk (= DS ≥ 4); after 20 years 8/9 required at least two sticks (DS ≥ 5); after 25 years 6/8 were wheelchair bound (DS =6) or confined to bed (DS= 7). We found mostly missense mutations and two nonsense mutations, occurring in different protein domains; some recurrent mutations (p.Gly696Ser; p.Ser591Pro; p.Val626Phe) were found. Conclusion: SPG8 did show is a slow but progressive, and finally severe, disease course. Although described as limited to pyramidal signs in the lower limbs, most of the patients developed with time a multisystem involvement. Some recurrent missense mutations were detected but a genotypic/phenotypic correlation could not be established.
Abstract 42 _ A rare type SPG77 in Czech Roma patient with uncomplicated HSP phenotype Anna Uhrova Meszarosova (1), Pavel Seeman (1), Renata Cibochova (2), Jana Drabova (3), Dana Safka Brozkova (1)
(1) DNA laboratory, Department of Paediatric Neurology, 2nd Faculty of Medicine Charles University and University Hospital Motol, Prague, Czech Republic
(2) Department of Neurology, 2nd Faculty of Medicine Charles University and University Hospital Motol, Prague, Czech Republic
(3) Department of Biology and Medical Genetics, 2nd Faculty of Medicine Charles University and University Hospital Motol, Prague, Czech Republic
SPG77 is very rare type of hereditary spastic parapalegia (HSP) caused by pathogenic variants affecting the FARS2 gene. FARS2 gene is a nuclear gene encoding mitochondrial phenylalanin-tRNA-syntetase. Defects in genes coding mitochondrial aminoacyl-tRNAsynthetases are usually manifested with the severe complicated phenotype (leukoencephalopathy, pontocerebellar hypoplasia or neurological impairement). Pathogenic variants in the FARS2 gene causing SPG77 have yet been described in only four families worldwide – two with severe complicated, two with pure uncomplicated phenotype.
We describe a 22-years old Czech man of Roma origin manifesting with pure HSP. Family history is negative. First gait problems appeared at 5 years of age. The progression has been very mild and slow, he is still able to walk without support after 17 years of disease duration. He has no additional clinical signs. We detected two most likely pathogenic variants in FARS2
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gene both in heterozygous status. Missense variant c.1082C>T (p.P361L) was detected using NGS of a gene panel sequencing. Variant has a low frequency 0.014 % in European non-Finnish population and was described recently with thecomplicated spastic paraplegia phenotype. CNV analysis of NGS data of a patient revealed gross deletion encompassing the first two exons of the FARS2 gene with introns included extended to first exon of neighbouring LYRM4 gene. The healthy mother carries only the c.1082C>T missense variant in heterozygous status. Father´s DNA is not available, we suppose the gross deletion to be inherited from father or occured de novo.
The harmfull impact of disrupted FARS2 gene has been confirmed repeatidly by several authors. All these facts lead us to assume that the combination of these two variants in FARS2 gene are the cause of HSP in our patient.Our patient is the fifth with SPG77 worldwide and from the third family described with pure phenotype.
Supported by Ministry of Health of the Czech Republic AZV 15-31899A.
Abstract 43 _ Patients with Hereditary Spastic Paraplegia exhibit reduction in spinal cord Katiane R. Servelhere (1), Raphael F. Casseb (2), Thiago J. de Rezende (1), Luciana P. Ramalho (1), Marcondes C. F. Junior (1). (1) School of Medical Sciences (FCM), University of Campinas, Campinas, Brazil; (2) Seaman Family MR Research Center, University of Calgary, Calgary, Canada
Introduction: Hereditary spastic paraplegias (HSP) are a heterogeneous group of neurodegenerative disorders characterized clinically by slowly progressive lower limb weakness and spasticity [1]. Corticospinal tract is the key target of damage in the disease and novel MRI techniques and software’s for assessment of the spinal cord (SC) can quantify gray (GM) and white (WM) matter areas separately, contributing to identify potential biomarkers for the disease [2]. Objective: To compare GM and total SC area in axial MR images of the cervical SC (Figure 1). Methods: We analyzed 25 HSP patients (3 SPG3A, 9 SPG7, 7 SPG4 and 6 SPG11; 10 men; mean age 50 years ± 17 years), and 17 healthy controls (4 men; mean age 44 ± 13 years). Image acquisition was performed in a 3T MRI scanner and T2*-weighted 2D images, which were assessed by the Spinal Cord Toolbox (SCT) [3]. Area metrics from GM and transversal cervical spinal area (CSA) were compared between groups. Statistical analyses were performed in SPSS using analysis of covariance and Bonferroni-corrected p-values<0.05. Results: Using age and gender as covariates, we found a significant atrophy in the patient group for the total transversal SCA and GM area (p=0.002 and p<0.001, respectively) Discussion and Conclusion: We were able to show that HSP significantly impacts the cervical SC structure, and the longitudinal investigation of SC area metrics can help characterize our findings and perhaps pave the way to make it useful as a biomarker. Acknowledgements: PNPD/CAPES.
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Figure 1. Transversal slices of the spinal cord. Original image (left), spinal cord mask (center) and gray matter mask (right.)
References
1. Boutry M, Morais S, Stevanin G. Update on the Genetics of Spastic Paraplegias. Curr Neurol Neurosci Rep 2019; DOI: 1007/s11910-019-0930-2.
2. da Graça FF, de Rezende TJR, Vasconcellos LFR, et al. Neuroimaging in Hereditary Spastic Paraplegias: Current use and future perspectives. Front Neurol 2019; DOI: 10.3389/fneur.2018.01117.
3. De Leener B, Lévy S,Dupont SM, et al. SCT: Spinal Cord Toolbox, an open-source software for processing spinal cord MRI data. Neuroimage 2017; 145:24-43.
Abstract 46 _ A case report of a Novel homozygous missense mutation in ARG1 gene in a Sudanese family Liena Elsayed,1* Inaam Mohammed,1 Ahlam Hamed,1 Maha Elseed,1 Mustafa Salih,2 Ashraf Yahia,1,7 Rayan Siddig,1, 1 Mahmoud Koko3,8, Amal Abd Allah1, Mustafa Elbashir,1 Muntaser Ibrahim,3 Alexis Brice, 4,6 Ammar Ahmed,1 and Giovanni Stevanin. 4, 5, 6 *Correspondence: Dr. Liena Elbaghir Omer Elsayed, Faculty of Medicine, University of Khartoum, Qasr Street,11111 Khartoum, Sudan. Emails: [email protected] 1Faculty of Medicine, University of Khartoum, Khartoum, Sudan. 2Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia. 3Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Sudan. 4Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Sorbonne Universités, UPMC Université Paris VI UMR_S1127, 75013 Paris, France. 5Ecole Pratique des Hautes Etudes, EPHE, PSL research university, 75014 Paris, France. 6APHP Pitié-Salpêtrière Hospital, Department of genetics, 75013 Paris, France. 7Department of Biochemistry, Faculty of Medicine, National University, Sudan. 8Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, Tuebingen, Germany.
Background: Arginases catalyze the last step in the urea cycle. Hyperargininemia is a rare autosomal recessive disorder of the urea cycle. It presents after the first year of age with regressions of milestones and evolves gradually into progressive spastic quadriplegia and cognitive dysfunction. Genetic studies reported various mutations in ARG1 gene that resulted in hyperargininemia due to a complete or partial loss of arginase activity. Case presentation: Five patients from an extended Sudanese family presented with regression of the acquired milestones, spastic quadriplegia, and mental retardation. Two patients had epileptic seizures and one patient had stereotypic clapping. Disease onset ranged from one to three years of age. Genetic testing using whole exome sequencing, done for the patients and a healthy parent, confirmed the presence of a novel missense variant in the ARG1 gene [Exon 4: g. 131902487T>A, c.434T>A, p.(Val145Glu)]. The variant was predicted pathogenic by four algorithms. It resulted in a change of the highly conserved hydrophobic amino acid valine located in the protein domain Ureohydrolase, Arginase subgroup to the acidic amino acid glutamate. Sanger sequencing of 13 sampled family members revealed complete co-segregation between the variant and the disease distribution in the family in line with an AR mode of inheritance. Biochemical analysis confirmed hyperargininemia. Conclusion: This study reports the first Sudanese family with ARG1 mutation. The reported variant is a loss of function missense mutation. Its pathogenicity is strongly supported by the clinical phenotype,
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the computational functional impact prediction, the complete co-segregation with the disease, and the biochemical assessment. Keyword Hyperargininemia, ARG1 gene, Whole exome sequencing, Sudan.
Abstract 47 _ The HIPK2 kinase/spastin axis in Hereditary Spastic Paraplegia (HSP): functional roles and potential therapeutic applications Francesca Sardina1, Gianmarco Dalla Zanna2, Alessandra Pisciottani1, Manuela Ferrara1, Marco Crescenzi3, Silvia Soddu4 , Andrew J. Grierson5, Carlo Casali2 , Cinzia Rinaldo1,4 1Institute of Molecular Biology and Pathology-CNR, Rome, Italy; 2Department of Medical and Surgical Sciences and Biotechnologies (DSBMC), Polo Pontino-University of Rome "Sapienza", Latina, Italy; 3Istituto Superiore di Sanità, Rome, Italy; 4Regina Elena National Cancer Institute, Rome, Italy. 5Sheffield Institute for Translational Neuroscience, University of Sheffield (UK)
The most common type of Hereditary spastic paraplegia (HSP) is due to heterozygous mutations in the SPG4 gene, encoding spastin, a microtubule severing protein involved in cytokinesis and intracellular/axonal transport. Recently, it has been shown that to increase spastin levels rescues the pathological phenotypes in HSP-patient-derived cells suggesting that intervening to modulate spastin levels may be a valid therapeutic strategy in neurodegeneration characterized by spastin misregulation. We found that spastin is regulated by the kinase HIPK2 in neural compartment. HIPK2 depletion leads to spastin downregulation in a proteasome-dependent manner and impairs axonal-transport. Mechanistically, we observed that HIPK2 specifically phosphorylates spastin at S268 and this phosphorylation stabilizes spastin protecting it from K48-poly-ubiquitination and proteasome degradation. Notably, HIPK2 overexpressio/activation increases spastin protein levels and rescues neuronal swelling defects in a spastin-deficient cell model that recapitulates HSP neurite defects. This finding provides the proof of principle that the manipulation of HIPK2/spastin axis might be a successful strategy to develop new therapeutic approaches to treat HSP. Furthermore, we are analyzing whether HIPK2-mediated spastin regulation has a role in SPG4-HSP variability by generating linphoblastoid cell lines derived from Italian SPG4-family harboring spg4 c751insA mutation with high intra familial clinical variability. Preliminary analyses show that early-onset patients present levels of spastin lower than controls and late-onset individuals of the same family.
Abstract 48 _ The cerebellar pathophysiology of Autosomal Recessive Cerebellar Ataxia 2 (ARCA2). Ioannis MANOLARASs1-4, Laurence REUTENAUER1-4, Helene PUCCIO1-4
1Départment de Médecine Translationnelle et Neurogénétique, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France. 2INSERM, U596, Illkirch, France. 3CNRS, UMR7104, Illkirch, France. 4Université de Strasbourg, Strasbourg, France.
Coenzyme Q10 (CoQ10) is an important lipid present in all membranes. CoQ10 is a strong antioxidant, and its most well characterized function is the channeling of electrons to complex III in the mitochondrial respiratory chain. CoQ10 biosynthesis occurs in the mitochondria. Mutations in genes coding for CoQ10 biosynthesis complex (complex Q) enzymes are causing
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CoQ10 deficiencies, a heterogeneous group of autosomal recessive conditions. ARCA2 is a rare form of early onset mild ataxia due to mutations in the COQ8A gene, coding for an ATPase involved in CoQ10 production by regulating complex Q. We previously demonstrated, in a constitutive COQ8A KO mice model, Purkinje cell (PC) specific dysfunction in the cerebellum. In order to uncover the molecular mechanism underlying the disease, we aimed at identifying dysregulated pathways in cerebellum. Using a candidate-based approach, we identified elevated glutamate neurotransmission which we hypothesize that leads to excitotoxicity and increased Ca2+ levels in PCs. Furthermore, a transcriptomic analysis on laser-dissected PC identified several pathways that are currently being explored. Finally, to further validate the role of PCs in ARCA2, we generated a PC-specific conditional KO mice. These mice are ataxic in agreement with PC specific dysfunction in the constitutive KO model, and also show dysregulated Ca2+ metabolism.
Abstract 49 _ The ataxia protein sacsin impacts on focal adhesion dynamics and cell migration Lisa E.L. Romano1, Tatiana V. Novoselova1, Ginevra Chioccioli Altadonna1, Abubakar Hatimy2, Konstantinos Thalassinos2 and J. Paul Chapple1 1William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, Charterhouse Square London, EC1M 6BQ, UK. 2Institute of Structural and Molecular Biology Division of Biosciences Darwin Building, University College London, Gower Street London, WC1E 6BT UK.
Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS) is a childhood-onset neurological disease with pyramidal spasticity and cerebellar ataxia. ARSACS results from mutations in the SACS gene that encodes sacsin. Previously we identified that loss of sacsin results in reduced mitochondrial health and altered organization of the intermediate filament cytoskeleton. Sacsin is a modular protein with conserved domains that suggest a proteostasis associated function. We hypothesized that loss of sacsin would alter solubility of its client. Using proteomics approaches, we identified sacsin interactors that accumulated in an insoluble fraction from sacsin knockout cells. These included cytoskeletal and focal adhesion associated proteins. Confocal microscopy revealed that the number and structure of focal adhesions was altered in sacsin knockout cells (generated by CRISPR/Cas 9 genome editing). Moreover, fluorescence recovery after photobleaching demonstrated that focal adhesion dynamics were reduce. We next identified the mechanisms underlying the altered focal adhesion dynamics and demonstrated directional migration is impaired in sacsin knockout cells. We are currently investigating if sacsin knockout cells differentiated along neuronal lineages exhibit altered migration, as this could be relevant to understanding the neurological phenotype of ARSACS patients.
Abstract 50 _ Multiple components of the intermediate filament cytoskeleton show altered organisation in sacsin deficient cells Ginevra Chioccioli Altadonna, Lisa E.L. Romano, J. Paul Chapple The William Harvey Research Institute, Charterhouse Square Barts and the London School of Medicine and Dentistry, Queen Mary University of London, EC1M 6BQ, UK.
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Autosomal Recessive Spastic Ataxia of Charlevoix Saguenay (ARSACS) is caused by a mutation in the SACS gene that encodes the protein sacsin. Based on domains that link it to molecular chaperones and the ubiquitin proteasome system it is hypothesised that sacsin functions in protein quality control. Previous studies have identified that loss of sacsin function disrupts the normal organisation of the vimentin filaments and neuofilaments. This includes the formation of perinuclear accumulations of vimentin in sacsin knockout (KO) SH-SY5Y cells and ARSACS patient dermal fibroblasts, as well as abnormal bundling of non-phosphorylated neurofilament in neurons from sacsin knockout mice. As loss of sacsin perturbs both vimentin and neuofilaments organisation we hypothesized that other types of intermediate filaments (IFs) may also be affected. We therefore used immunofluorescent labelling and confocal microscopy to investigate the organisation of desmin, lamin B2, α-internexin, and peripherin in sacsin knockout and control SH-SY5Ycells. With the exception of lamin B2 all other IFs exhibited altered localisation in sacsin KO cells relative to controls. We also analysed levels of soluble IFs in sacsin KO cells, identifying that insoluble IF proteins accumulated in sacsin KO cells. These data indicate that loss of sacsin impacts on multiple classes of IFs. We are currently investigating if specific IFs become trapped in abnormal accumulations because of IF:IF interactions or because of a more direct effect of loss of sacsin.
Abstract 51 _ Variants acting as SARS2 eQTLs modify spastic paraplegia type 4 age of onset. Livia Parodi1, François-Xavier Lejeune1, Mathieu Barbier1, Alexis Brice1, Giovanni Stevanin1,2 and Alexandra Durr1
1.Institut du Cerveau et de la Moelle épinière (ICM), INSERM, CNRS, Assistance Publique-Hôpitaux de Paris (AP-HP), Sorbonne Université, Pitié-Salpêtrère University Hospital, Paris, France 2.Ecole Pratique des Hautes Etudes (EPHE), Paris Sciences et Lettres (PSL) Research University, Neurogenetics Group, Paris, France
Introduction: Hereditary Spastic Paraplegias (HSPs) are rare neurological disorders caused by the progressive distal degeneration of the corticospinal tracts. Mutations in SPAST, encoding Spastin, are the most frequent cause of HSP. Recently, through the analysis of 842 SPAST mutated patients, we showed that mutation nature accounts for some of the age at onset variability and that sex influences the disorder penetrance. To identify additional age at onset modifiers, a GWAS analysis was performed on 134 SPAST truncating mutations carriers.
Materials and Methods: Patients were genotyped using Illumina InfiniumOmni2.5Exome-8 kit. Single variant test was performed using a logistic mixed model for binary traits available with GMMAT R package, adjusted for sex and patients’ relatedness. Patients with very discordant age at onset were compared (≤15 years versus ≥45 years).
Results: A group of SNPs in linkage disequilibrium (r2>0.8) reached a p-value suggestive for association (top p-value = 10e-6). The 7 suggestive SNPs are located on chromosome 19 and are described as eQTLs of SARS2 gene in GTEx database. Among the genotyped patients, a significantly lower age at onset (p<0.0001, Mann-Whitney test) was associated with the minor allele at all SNPs, as well as a tendency to a decreased disorder severity. Increased SARS2 protein levels (p = 0.03, paired t-test) were detected by Western immunoblotting in primary blood lymphoblasts of minor alleles carrier patients, furthermore confirming their role as eQTLs.
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Conclusions: Pathogenic mutations affecting SARS2, encoding a mitochondrial seryl-tRNA synthetase, have already been linked to progressive spastic paraparesis onset, suggesting it as a good candidate. iPSCs-derived neurons and Drosophila model are being used to further confirm its role as SPAST-HSP age of onset modifier.
Abstract 53 _ Hallmarks of Purkinje cell degeneration and transcriptional deficits in a new SCA7 140Q/5Q knock-in mouse model
Anna Niewiadomska-Cimicka (1), Celine Keime (1), Aurelie Eisenmann (1), Chantal Weber (1), Frédéric Doussau (2), Antoine Hache (1), Nadia Messaddeq (1), Philippe Isope (2), Yvon Trottier (1)
(1) Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC); INSERM, U1258; CNRS, UMR 7104; Université de Strasbourg; 67404 Illkirch Cedex, France (2) Institut des Neurosciences Cellulaires et Intégratives (INCI); CNRS UPR 3212; Université de Strasbourg; 67084 Strasbourg, France
Spinocerebellar Ataxia Type 7 (SCA7) belonging to ADCAs is pathomechanistically related to polyglutamine expansion disorders, which include SCA 1-3, 6 and 17, and Huntington’s disease. SCA7 is caused by a polyglutamine expansion in ATAXIN-7, a subcomponent of transcriptional coactivator SAGA and affects primarily brainstem, retina and cerebellum. Our new SCA7140Q/5Q KI mouse model remarkably recapitulates cardinal features of SCA7 and bears the potential for pre-clinical trials. SCA7 mice show motor dysfunctions already starting at 16 weeks and die after 1 year of disease duration. Purkinje cells (PC) showed several degenerative signs including alteration of their size and circularity, impairment of cerebellar glutamate input and electrophysiological spiking dysfunction. Ultrastructural analysis revealed a dilated Golgi apparatus and abnormal mitochondria. At late stage, many PC showed dark degeneration. RNA-seq of SCA7 cerebellum indicated that transcriptional alterations precede motor dysfunction, and coincide with the abnormal accumulation of mutant Ataxin-7. Using publically available cell-type specific gene expression datasets, we found that PC-specific genes are largely downregulated. Interestingly, we identified PC-specific transcriptional signature commonly downregulated in SCA1, SCA2 and SCA7. Searching for mechanisms underlying PC-specific gene downregulation, we pointed out the differences in PC promoter composition in comparison to cerebellar granule cells. We identified several microRNAs as potential regulators of PC-specific downregulated genes, which were otherwise shown to be deregulated in the plasma of SCA7 patients. Moreover, we identified Jun/Fos as potential transcription regulators of PC-specific downregulated genes. Our results point out toward preferential downregulation of PC-specific genes that share common regulatory mechanisms.
Abstract 58 _ Expanding the spectrum of AP5Z1 mutations (SPG48): a phenotypic, genotypic and functional analysis Marianthi Breza1*, Jennifer Hirst2*, Viorica Chelban3,4*, Thomas Bourinaris3, Jana Vandrovcova3, Georgios Velonakis6, Efstratios Karavasilis6, Chia-Ju Lee3, Sondos Alikhwan3, John Tzartos1, Chrisoula Kartanou1, Leonidas Stefanis1, Nicholas Wood3,5, Georgia Karadima1, Henry Houlden3,5, Georgios Koutsis1
*equally contributed
1 Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece. 2 University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom. 3Department of Neuromuscular Disease, Institute of Neurology, University College London, London WC1N 3BG, UK. 4Department of Neurology and Neurosurgery, Institute of Emergency Medicine, Toma Ciorbă 1, 2052 Chisinau, Republic of Moldova.
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5Neurogenetics Laboratory, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK. 62nd Department of Radiology, National and Kapodistrian University of Athens, Medical School, Attikon Hospital, Athens, Greece
Introduction
Biallelic mutations in the AP5Z1 gene are known to cause a very rare complex form of hereditary spastic paraplegia (HSP) referred to as SPG48. SPG48 follows an autosomal recessive inheritance pattern. To date, only 4 pathogenic mutations in the AP5Z1 gene have been reported. The aim of this study was to investigate a Greek HSP cohort for mutations in the AP5Z1 gene.
Methods
We performed whole exome sequencing (WES) in 38 probands with HSP phenotype negative for variants in common HSP genes. Functional studies were conducted on fibroblast cell lines derived from the patient identified.
Results
We identified a Greek patient carrying a novel homozygous frameshift pathogenic variant c.1719delG (p.Gly573fs*) in the AP5Z1 gene (NM_014855.2), confirmed by Sanger sequencing. The patient was a 65-year-old man with known epileptic seizures (generalized tonic-clonic) since he was 30 years old that presented at the age of 48 years with a progressive spastic gait disorder, complicated by peripheral neuropathy. Brain MRI findings included thinning of corpus callosum and ears-of-the lynx. Functional studies performed on fibroblast cell lines support and expand previous findings from SPG48 cell lines showing defects in endosome/lysosome homeostasis.
Conclusion
Insights from the present report expand the clinical and genetic spectrum of SPG48 and our understanding of the underlying pathomorphological processes. The exact pathomechanism of AP5Z1-associated complicated HSP remains, however, to be elucidated.
Abstract 59 _ Hereditary Spastic Paraplegia: clinical spectrum and genetic landscape in Greece Marianthi Breza1, Viorica Chelban2,3, Thomas Bourinaris2, Jennifer Hirst4, Jana Vandrovcova2, Chia-Ju Lee2, Sondos Alikhwan2, Nour Haridd2, Chrisoula Kartanou1, Stephanie Efthymiou2, David S Lynch2, Arianna Tucci2, Marios Panas1, Nicholas Wood 2,5, Georgia Karadima1, Henry Houlden2,5, Georgios Koutsis1
1 Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece. 2Department of Neuromuscular Disease, Institute of Neurology, University College London, London WC1N 3BG, UK. 3Department of Neurology and Neurosurgery, Institute of Emergency Medicine, Toma Ciorbă 1, 2052 Chisinau, Republic of Moldova. 4University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom. 5Neurogenetics Laboratory, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK.
Introduction
Hereditary spastic paraplegia (HSP) is a group of rare, inherited disorders characterized mainly by a progressive gait disorder. HSP can present as pure or complicated by other neurological manifestations and all types of inheritance are reported. To date, more than 80 different genes
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are reported to cause HSP. The aim of this study was to investigate the clinical spectrum and genetic landscape of HSP in the Greek population.
Methods
We analyzed the clinical and genetic characteristics of 87 index HSP patients referred to the Neurogenetics Unit, Eginition Hospital, University of Athens over a 22-year period. Probands were screened with a combination of next generation sequencing (NGS) techniques, MLPA and Sanger sequencing.
Results
A genetic diagnosis was reached in 53 index cases (60.9%), identifying 21 novel variants in known HSP genes. Pathogenic mutations were found in SPAST, SPG11, KIF5A, CYP7B1, ATL1, REEP1, NIPA1, SPG7, PLP1, ABCD1, PSEN1 and AP5Z1. Mutations in SPAST, KIF5A and ATL1 were the most common causes of autosomal dominant HSP and in SPG11 and CYP7B1 of autosomal recessive HSP. Interestingly, we identified variants of SPG11 in five late-onset index patients, which are unique to the Greek population, a PSEN1 mutation (T291P) presenting as spastic paraparesis and a novel homozygous AP5Z1 mutation.
Conclusion
Our results provide comprehensive genetic data on the Greek HSP population, confirming findings in other European populations and supporting the early use of whole exome sequencing as a diagnostic tool in these patients.
Abstract 60 _ Characterization of speech patterns in Hereditary Spastic Paraplegias Laís Alves Jacinto-Scudeiro (6), Gustavo Dariva Machado (1), Annelise Ayres (9), Daniela Burguêz (1), Marcia Polese-Bonato (7), Carelis González-Salazar (11), Marina Siebert (3,8), Marcondes Cavalcante França Junior (10,11), Marina Martins Pereira Padovani (12), Maira Rozenfeld Olchik (5), Jonas Alex Morales Saute (1,2,4,6) (1) Medical Genetics and (2) Neurology services, and (3) Unit of Laboratorial Research /Experimental Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil; (4) Departments of Internal Medicine and (5) Surgery and Orthopedics, (6) Graduate Program in Medicine: Medical Sciences, (7) Biochemistry and (8) Gastroenterology and Hepatology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil. (9) Graduate Program in Health Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre, UFCSPA, Porto Alegre, RS, Brazil. (10) Department of Neurology, Faculdade de Ciências Médicas and (11) Postgraduate program in Medical Physiopathology, Universidade Estadual de Campinas, Campinas, SP Brazil. (12) Faculdade de Ciências Médicas da Santa Casa de São Paulo, São Paulo, SP, Brazil.
Introduction: Hereditary spastic paraplegias (HSP) is a heterogeneous group of genetic diseases, which little is known about abnormalities of speech. We aim evaluating the frequency and clinical characterization of dysarthria in the most prevalent forms of HSP. Methods: We carried out a case-control study in two Brazilian hospitals. Patients with genetic diagnosis of HSP were evaluated by the Protocol for the Evaluation of Acquired Speech Disorders (PADAF) and by objective measures of speech using Praat software. Clinical evaluation was performed through the consensus of five speech therapists with experience in the area. Results: Thirty-six patients with spastic paraplegia type 4 (SPG4), five with SPG11, four with SPG5 and cerebrotendinous xanthomatosis, three with SPG7, two with SPG3A and 30 healthy controls participated in the study. To date, 10 patients with SPG4 and 5 patients with SPG11
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have been analyzed. Patients with SPG11 had a higher prevalence of dysarthria (100% of patients) with changes in breathing, phonation, resonance, articulation and prosody. Patients with SPG4 presented phonation (2/10 hoarse and breathy voices; 4/10 alterations in vocal intensity) and articulation alterations with greater impairment in the tasks of diadochokinesia (6/10) and tongue movement (3/10). Acoustic analysis of speech showed changes in the maximum time of phonation, fundamental frequency, shimmer and diadochokinesia for both groups. Conclusions: Patients with SPG4 and SPG11 presented mild dysarthria, but with a greater impact on speech intelligibility for SPG11. Detailed characterization of speech patterns in the different forms of HSP will assist in the diagnosis and treatment of these diseases.
Abstract 62 _ Biallelic expansions in RFC1 can be detected by clinical routine short read whole genome sequencing Linda Säll1, Luca Verrecchia2, Tatjana Tomanovic2, Per Svenningsson1,3, Daniel Nilsson4, Martin Paucar 1,3
1Department of Neurology, Karolinska University Hospital, 2Department of Otorhinolaryngology, Karolinska University Hospital, 3Department of Clinical Neuroscience, Karolinska Institutet, 4Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
Objective: To characterize the underlying genotype in a Swedish 53-year-old man affected by cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS).
Background: CANVAS is a rare ataxia syndrome. Only recently, a biallelic intronic AAGGG repeat expansion in the replication factor C subunit 1 (RFC1) was described as the genotype associated with CANVAS.
Methods: Oral and written consent were obtained from the patient who went through clinical examinations, structural neuroimaging, neurophysiological tests, evaluation of the vestibular system and genetic analyses.
Results: The main features in this case consist of adult-onset axial ataxia, paresthesia in hands and feet as well as dizziness. The rate of ataxia progression is slow, his vestibulo-ocular reflex (VOR) was abnormal. This patient is also affected by paroxysmal cough. ENeG demonstrated sensory axonal polyneuropathy and neuroimaging a severe atrophy of the vermis and superior cerebellar peduncles. Taken together the patient meets the current criteria for CANVAS. After ruling out the most common trinucleotide expansions associated with ataxia a short read whole genome sequencing (WGS) was applied. This analysis demonstrated the patient harbors the bialleic AAGGG repeat expansion in RFC1.
Conclusions: Our findings illustrate the utility of short read WGS. To our knowledge this is the first genetically proven case of CANVAS in Scandinavia. What lies ahead is to dissect the underlying mechanism of disease.
References:
1. Szmulewicz DJ, et al. Proposed diagnostic criteria for cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS). Neurol Clin Pract. 2016;6(1):61-68.
2. Cortese, A. et al. Biallelic mutations of an intronic repeat in RFC1 is a common cause of late-onset ataxia. Nature Genetics 2019; 51(4): 649-658.
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Abstract 63 _ Natural History of Movement Abnormalities on Hereditary Spastic Paraplegias: validation of timed-gait measuring functional instruments Gustavo Dariva Machado (1), Ana Paula Janner Zanardi (5), Valéria Feijó Martins (5), Daniela Burguêz (1), Laís Alves Jacinto Scudeiro (4), Leonardo Alexandre Peyré-Tartaruga (5), Jonas Alex Morales Saute (1,2,3,4). (1) Clinical Genetics and (2) Neurology services, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil; (3) Department of Internal Medicine, (4) Postgraduate Program in Medicine: Medical Sciences, (5) Exercise Research Laboratory (LAPEX), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
Introduction: Hereditary Spastic Paraplegias (HSP) are a group of diseases characterized by progressive spastic paraparesis, which natural history is little known. We aim defining validity of timed-gait measuring instruments and subsequently their sensitivity to change and Minimal Clinically Important Difference (MCID). Methods: The MOVESPAST study has two phases: cross-sectional and cohort study. All individuals with HSP molecular diagnosis from a Brazilian hospital were recruited. We applied 6-minute walk test (6MWT), 10-meter walk test (10MWT), Timed Up and Go test (TUG), Locomotor Rehabilitation Index (LRI) and semi-quantitative Spastic Paraplegia Rating Scale (SPRS) on baseline and will reapply after 18 and 30 months, defining sensitivity to change and MCID. Healthy controls (age and sex-matched) were recruited for cross-sectional phase. Results: Timed-gait instruments were applied on 25/32 HSP patients and 25 control individuals. Patients presented worse performances than controls in all evaluated instruments (p<0.001 for all comparisons). We found a difference of 313.8m on 6MWT, 34% on IRL, 0.99log (seconds) on 10MWT and 0.944log (seconds) on TUG (self-selected speed). All instruments presented significant (p<0.001) moderate to strong correlations to SPRS (R=0.683-0.803) and disease stage (R=0.666-0.935). Baseline MCID was estimated by the distributive method. Conclusion: Timed-gait instruments presented discriminatory and construct validity for HSPs, and are theoretically sensitive to change due to their quantitative nature. The study will be complemented by space-time parameters of gait analysis. Interim analysis data at 18 months will be presented. Results on longitudinal phase of the study will help understand natural history of HSPs and design future clinical trials.
Abstract 64 _ Are Cognitive Changes in Hereditary Spastic Paraplegias Restricted to Complicated Forms? Laís Alves Jacinto-Scudeiro (6), Gustavo Dariva Machado (1), Annelise Ayres (9), Daniela Burguêz (1), Marcia Polese-Bonato (7), Carelis González-Salazar (11), Marina Siebert (3,8), Marcondes Cavalcante França Junior (10,11), Maira Rozenfeld Olchik (5), Jonas Alex Morales Saute (1,2,4,6) (1) Medical Genetics and (2) Neurology services, and (3) Unit of Laboratorial Research /Experimental Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil; (4) Departments of Internal Medicine and (5) Surgery and Orthopedics, (6) Graduate Program in Medicine: Medical Sciences, (7) Biochemistry and (8) Gastroenterology and Hepatology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil. (9) Graduate Program in Health Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre, UFCSPA, Porto Alegre, RS, Brazil. (10) Department of Neurology, Faculdade de Ciências Médicas and (11) Postgraduate program in Medical Physiopathology, Universidade Estadual de Campinas, Campinas, SP Brazil.
Introduction: Hereditary Spastic Paraplegias (HSP) is a heterogeneous group of genetic diseases, which little attention has been given to cognitive abnormalities. We aimed characterizing cognitive functions of patients with pure and complicated forms of HSP.
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Methods: A two-center cross-sectional, case-control study was performed. All individuals underwent cognitive assessments by a single evaluator through screening tests (Mini Mental State Examination - MEEM and Montreal Cognitive Assessment - MOCA) and tests to assess specific cognitive functions (Verbal fluency with phonological restriction – FAS; Verbal categorical fluency - FAS-cat and Rey's Verbal Auditory Learning Test –RAVLT). Wechsler Intelligence Scale for Children (WISC III) was applied to patients under 17 years-old. Results: Fifty four patients with genetically confirmed HSP diagnosis, 36 with spastic paraplegia type 4 (SPG4), 5 SPG11, 4 SPG5, 4 cerebrotendinous xanthomatosis (CTX), 3 SPG7 and 2 SPG3A, and 10 healthy, unrelated control subjects, with similar age, sex and education participated in the study. SPG4 patients had worse performances in MOCA, FAS, FAS-cat and RAVLT when compared to controls. Most SPG4 patients presented cognitive changes not compatible with dementia, performing poorly in memory, attention and executive functions. SPG5 patients scored lower in executive functions and memory, and SPG7 patients performed poorly on memory tasks. All evaluated cognitive functions were markedly altered in CTX and SPG11 patients. Conclusions: Cognitive abnormalities are frequent in HSP, being more severe in complicated forms. Impairments of cognition on pure HSPs might affect patients’ lives, decreasing families´ socioeconomic status and contributing to the overall disease burden.
Abstract 66 _ Clinical, imaging, biomarker, and molecular delineation of COQ8A-ataxia: a multicenter study of 64 patients Andreas Traschütz (1,2), Lucia Laugwitz (3), Mathieu Anheim (4, 5, 6), Jonathan Baets (7, 8, 9), Nazli Basak (10), Alexandra Durr (11, 12), Rita Horvath (13), Thomas Klopstock (14, 15, 16), Renato Munhoz (17), Filippo M. Santorelli (18), Bart van de Warrenburg (19), Hélène Puccio (20, 21, 22, 23), Felix Distelmaier (24), Ginevra Zanni (25), Dave Pagliarini (26), Matthis Synofzik (1,2); for the COQ8A research consortium (1) Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany (2) German Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Tübingen, Germany (3) Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany (4) Service de Neurologie, Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, Strasbourg, France (5) Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France (6) Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964/CNRS-UMR7104/Université de
Strasbourg, Illkirch, France (7) Neurogenetics Group, University of Antwerp, Antwerp (8) Institute Born-Bunge, University of Antwerp, Antwerp, Belgium (9) Department of Neurology, Antwerp University Hospital, Antwerp, Belgium (10) Suna and Inan Kiraç Foundation, Neurodegeneration Research Laboratory, KUTTAM, Koç University Med School, Istanbul (11) Brain and Spine Institute (ICM), Sorbonne Université, Pitié-Salpêtrière University Hospital, Paris, France (12) AP-HP, Department of Genetics, Pitié-Salpêtrière University Hospital, Paris, France (13) Department of Clinical Neurosciences, University of Cambridge, Cambridge (14) Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University of Munich, Munich (15) German Center for Neurodegenerative Diseases (DZNE), Munich, Germany (16) Munich Cluster for Systems Neurology (SyNergy), Munich, Germany (17) Department of Pediatrics and Neuromuscular and Neurometabolic Clinic McMaster University Medical Center Hamilton
Ontario (18) IRCCS Fondazione Stella Maris, Pisa (19) Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology,
Nijmegen (20) Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch (21) INSERM, U1258, Illkirch, France (22) CNRS, UMR7104, IIllkirch, France (23) Université de Strasbourg, Strasbourg, France (24) Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital Duesseldorf,
Medical Faculty, Heinrich Heine University, Duesseldorf
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(25) Unit of Neuromuscular and Neurodegenerative diseases, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome
(26) Morgridge Institute for Research, Madison, WI 53715, USA; Department of Biochemistry, University of Wisconsin-Madison, Madison, WI
Background: The rapid expansion of autosomal-recessive ataxia (ARCA) genes needs to be translated into preparation of first treatment trials. ARCA due to mutations in COQ8A (ADCK3) might be particularly susceptible to treatment, e.g. by coenzyme Q10 (CoQ10) compounds. We here map the phenotypic, molecular and neuroimaging spectrum of COQ8A-ataxia, and provide first progression data including response to CoQ10, leveraging a large multicenter cohort of 64 patients. Results: COQ8A-ataxia presents as a multisystemic, early-onset cerebellar ataxia (median onset: 7 years, IQR 4-15), with complicating features ranging from epilepsy (32%) and intellectual disability (49%) to exercise intolerance (25%) and hyperkinetic movement disorders (41%), including dystonia and myoclonus as main presenting symptoms. Missense variants were more frequently associated with multisystemic damage than loss-of-function variants (83% vs 53%, p = 0.044), suggesting gain of function mechanisms. Protein modelling and molecular analysis of purified variants demonstrated a wide range of detrimental effects of different COQ8A variants. Cerebellar atrophy was universal on MRI, with cerebral atrophy or remarkable dentate and pontine T2 hyperintensities in up to 28%. Cross-sectional (n = 34) and longitudinal (n = 7) assessments consistently indicated a mild to moderate progression of ataxia (SARA: 0.45/year). CoQ10 led to improvement by anecdotal report in 14/30 patients, and in 8/11 with quantitative longitudinal assessments (SARA: -0.88/year).
Sample size calculations demonstrate that 20 patients are required to demonstrate efficacy for interventions to at least stabilize disease. Conclusions: This comprehensive characterization of COQ8A-ataxia provides a deeper understanding of the disease and paves the way towards large-scale natural history studies and upcoming treatment trials in COQA-ataxia.
Abstract 67 _ From bench to bedside: STN-deep brain stimulation is effective in SCA3 with parkinsonian symptoms Martina Minnerop (1,2), Peter Pieperhoff (1), Sabine Fliegen (2), Christian Johannes Hartmann (2), Alexia-Sabine Moldovan (2), Tomke Müttel (3), Ulrike Kahlen (3), Ullrich Wüllner (4,5), Thomas Klockgether (4,5), Lars Wojtecki (2), Svenja Caspers (1,6), Katrin Amunts (1,7), Jan Vesper (8), Alfons Schnitzler (2), Stefan Jun Groiss (2)
(1) Institute of Neuroscience and Medicine (INM-1), Research Centre Juelich, Juelich, Germany (2) Center for Movement Disorders and Neuromodulation, Department of Neurology and Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany (3) Department of Neurology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany (4) Department of Neurology, University Hospital Bonn, Germany (5) German Center for Neurodegenerative Diseases, Bonn, Germany (6) Institute for Anatomy I, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany; JARA-BRAIN, Juelich-Aachen Research Alliance, Juelich, Germany (7) C. and O. Vogt Institute for Brain Research, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany (8) Department of Functional and Stereotactic Neurosurgery, Center for Neuromodulation, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany.
Spinocerebellar ataxia type 3 (SCA3) is characterized by cerebellar ataxia. There is pronounced involvement of the striatonigral system, including the subthalamic nucleus (STN), but Parkinsonian symptoms (PDsymptoms) are rarely observed. We wanted to quantify STN atrophy in SCA3 patients by MR morphometry. The question arises whether DBS of the STN is an effective therapy for SCA 3 patients presenting PDsymptoms.
We investigated the STN volume on T1-weighted MR images by applying cytoarchitectonic maps (JuBrain) and deformation-based morphometry in eleven SCA3 patients (7 males, age
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41.7±9.1 years), one of them also presenting PDsymptoms. The volumes were compared to age- and sex- matched controls and 196 elder participants of the 1000BRAINS study. Additionally, the effects of DBS in one SCA3 patient with PDsymptoms are reported.
SCA3 patients exhibited a reduction of the STN volume compared to controls and both groups showed an age related volume decline. Remarkably, the STN volumes of patients with lower repeat lengths (≤ 70 repeats, N=4) were closer to the normal range. This applied also to the single SCA3 patient with PDsymptoms. During the disease course he developed L-dopa-related fluctuations. After DBS of the STN, he showed an excellent benefit. His gait, however, was still impaired by cerebellar ataxia and polyneuropathy.
SCA3 patients have a lower STN volume compared to controls. Pronounced atrophy of the STN in SCA3 could prevent the development of PDsymptoms. Conversely, our SCA3 patient presenting with PDsymptoms showed less STN atrophy, supporting the notion that these very patients may be suitable candidates for DBS.
Abstract 68 _ EUROHSP: mission and goals
Marina Zapparoli (Italy) President EURO-HSP, Jean Benard, Président ASL- HSP France, Scientific Advisor Euro HSP
EUROHSP represents 10 national HSP patient associations: Austria, Denmark, France, Italy, Netherlands, Norway, Spain, Sweden, Switzerland and United Kingdom. Our federation provides a unified European voice for people of any age affected by HSP throughout Europe.
The mission of EUROHSP is; to empower its members, to promote patient-centric research on HSP and to take collective action to address the challenges people with HSP face in accessing an accurate diagnosis and optimal treatment and care.
Our strategic goals are to:
1) Provide a strong voice for HSP patients at a European level
2) Support member organisations to be more effective and sustainable
3) Influence the HSP research agenda so it is more focused on patient-centric outcomes
4) Secure the support of key researchers.
In detail, we seek to:
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• Push for the establishment of a harmonious European HSP patient registry which can encourage pharmaceutical companies to invest in HSP
• Put pressure on the EU via EURORDIS to make HSP a research priority
• Encourage SPATAX to involve patients when defining research priorities in HSP
• Create a forum with researchers to discuss research priorities from a patient perspective, thereby facilitating patient involvement via the EuroHSP member network.
• Develop a database identifying who is working on which HSP genes.
• Coordinate with the ERN-RND (European Reference Networks for Rare Neurological Diseases) to provide the best patient experience.
Abstract 71 _ Patients with Cerebellar Ataxia, Vestibular Areflexia and Neuronopathy Syndrome (CANVAS) of Polynesian ancestry have a novel conformation of their RFC1 repeat. Roxburgh, Richard (1,2), Beecroft, Sarah* (3), Cortese, Andrea* (4), Dyer, Zoe (1), Mossman, Stuart (5), Wu, Teddy (6), Pelosi, Luciana (1), Mulroy, Eoin (1), Leadbetter, Ruth (5), Chancellor, Andrew (7), Anderson, Tim (6,8), Cutfield Nick (9), Taylor, Rachael (2), Ravenscroft, Gina (3), Sullivan, Roisin (x), Reilly, Mary† (4), Houlden, Henry† (4), Laing, Nigel† (3)
1. Neurology Dept. Auckland City Hospital, Auckland New Zealand 2. Centre for Brain Research Neurogenetics Research Clinic, University of Auckland, Auckland, New Zealand 3. Centre for Medical Research University of Western Australia, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia 4. Department of Neuromuscular Disease, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK. 5. Neurology Dept, Wellington Hospital, Wellington, New Zealand 6. Neurology Dept, Christchurch Hospital, Christchurch, New Zealand 7. Neurology Dept, Tauranga Hospital, Tauranga, New Zealand 8. Department of Medicine, University of Otago, Christchurch, New Zealand. 9. Neurology Dept, Dunedin Hospital, Dunedin, New Zealand * these authors contributed equally, † these authors contributed equally
Cerebellar ataxia with neuronopathy and bilateral vestibular areflexia syndrome (CANVAS) is a recently recognised neurodegenerative disease with onset usually in adulthood. The genetic basis for a large proportion of Caucasian patients was recently described to be due to biallelic expansion of a pentanucleotide repeat within intron 2 of RFC1. Here, we describe CANVAS genetic testing in the Māori and Cook Island populations from New Zealand. We show a novel, possibly population-specific, configuration of the pathogenic pentanucleotide repeat in all tested patients. This demonstrates that the RFC1 locus is complex. We also describe their clinical features and compare them with our European patients.
Abstract 73 _ Expanding the clinical and genetic spectrum of PRUNE1-related disorder: another HSP gene? Stefania Magri (1), Francesca Balistreri (1), Stefano D’Arrigo (2), Cinzia Gellera (1), Chiara Pantaleoni (2), Daniela Di Bella (1), Franco Taroni (1) (1) Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
(2) Unit of Developmental Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
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The PRUNE1 gene encodes a member of the phosphoesterases protein superfamily involved in the regulation of cell migration. Bi-allelic PRUNE1 mutations cause Neurodevelopmental disorder with Microcephaly, Hypotonia, and variable Brain Anomalies (NMIHBA, #617481). Reported patients (47 individuals from 26 unrelated families) are characterized by hypotonia and severe-to-profound developmental delay, microcephaly, cerebral and cerebellar atrophy, thin/hypoplastic corpus callosum and delayed myelination, variably associated with seizures, neuromuscular signs and respiratory insufficiency. Here, we report a 15-year-old girl presenting with a congenital spastic-dystonic tetraparesis, mostly affecting lower limbs, who was initially diagnosed as cerebral palsy. At MRI, she presented an SPG11-like phenotype with thin corpus callosum and involvement of periventricular white matter. Following clinical onset of a similar phenotype in a second sib, a genetic etiology was hypothesised and mutations in all known HSP genes were excluded by NGS gene panel approach. Whole-exome sequencing in the two sibs revealed compound heterozygous PRUNE1 variants: the recurrent NMIHBA pathogenic variant p.Asp106Asn along with a novel p.Pro270Leu missense variant. The clinical presentation is overlapping between the two sibs and is significantly less severe compared to the previously reported NMIHBA patients. In particular, our patients present slowly progressive congenital spastic-dystonic tetraplegia with episodic dysarthria and dysphagia without microcephaly and seizure. They exhibit language disturbances but normal non-verbal cognitive performance. Our data suggest that bi-allelic PRUNE1 mutations may cause complex spastic tetraparesis without microcephaly, dysmorphic features, and cognitive impairment, thus expanding the clinical spectrum of PRUNE1-related disorder. (Grants: GR-2016-02363337 to S.M., RF-2016-02361285 to C.G.)
Abstract 74 _ A de novo missense mutation in the TRPC3 gene causing congenital ataxia: confirming a role for TRPC3 in spinocerebellar ataxia in humans. Daniela Di Bella (1), Stefania Magri (1), Elisa Sarto (1), Cinzia Gellera (1), Francesca Darra (2), Anna Ardissone (3), FrancoTaroni (1). (1) Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy; (2) Department of Child Neuropsychiatry, University of Verona, Italy; (3) Unit of Child Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
Introduction. The transient receptor potential channel TRPC3 is a nonselective cation channel, highly expressed in Purkinje cells. Genetic mouse models of TRPC3 dysfunction exhibit cerebellar ataxia. One heterozygous toxic gain-of-function missense variant in the TRPC3 gene was reported in a sporadic patient with adult-onset cerebellar ataxia (SCA41). Methods. A probe-based NGS panel covering >100 ataxia genes was used for genetic analysis of a 3-year-old patient with a congenital form of ataxia with cerebellar hypotrophy at MRI. Results. Genetic screening identified two novel missense variants, not present in genetic databases, in ITPR1 and TRPC3 genes. While the ITPR1 variant was inherited from the healthy mother, the TRPC3 variant (Pro>Leu in a transmembrane domain) appeared to have arosen de novo, thus allowing to classify it as likely pathogenic. The proband is the second child of healthy nonconsanguineous parents, born after an uncomplicated full-term pregnancy and was referred to the neuropsychiatryst because of global developmental delay, hypotonia
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and dysequilibrium. She progressively developed a cerebellar syndrome with gait ataxia. Interestingly, worsening of the ataxia symptomatology is reported to be triggered by febrile episodes. Brain MRI performed at age 2 year showed global cerebellar hypoplasia, in the absence of any brainstem or supratentorial abnormalities. Conclusions. Our data suggest that de-novo mutations of the murine ataxia gene TRPC3 could be a rare cause not only of adult-onset ataxia, but also of early-onset/congenital nonprogressive cerebellar ataxia in humans and that their screening should be implemented in this subgroup of disorders. (Grants: GR-2016-02363337 to S.M., RF-2016-02361285 to C.G.)
Abstract 76 _ Hereditary spastic paraplegia: massive sequencing of 70 genes in a large cohort of 812 cases Mélanie Papin (1,2),* Guillaume Banneau (3), Claire-Sophie Davoine (1,2)*, Mathilde Mairey (1,2), Laure Raymond (1,2), Liena Elsayed (1,2,4), Ashraf Mohamed Osman (1,2,4), Livia Parodi (1,2), Bophara Kol (3), Laurène Tissier (3), Sara Morais (1,2,5), Giovanni Vazza (6), Alexandra Durr (1,3), Eric Leguern (1,3), Giovanni Stevanin (1,2)
1 Institut du Cerveau et de la Moelle épinière (Sorbonne Universités, UPMC Université Paris 06 UMR S1127, INSERM U1127, CNRS UMR 7225), Paris, France ; 2Ecole Pratique des Hautes Etudes, Paris, France ; 3Fédération de génétique, APHP, CHU Pitié Salpêtrière, Paris, France ; 4 University of Khartoum, Sudan ; 5 UnIGENe, IBMC, Porto, Portugal ; 6 University of Padua, Italy.
Hereditary Spastic Paraplegias (HSPs) are a heterogeneous group of neurodegenerative disorders characterized by lower limb spasticity and weakness. Genetically, HSPs are complex with four modes of inheritance described, with >70 genes identified. Approximately 60% of the families remain without molecular diagnosis reinforcing their genetic heterogeneity.
This heterogeneity makes classical molecular tests time-consuming and difficult. Thus, we decided to develop a kit that couples a targeted capture and next generation sequencing to analyse 70 genes potentially involved in HSPs.
The kit has been used to sequence and analyse 812 index patients (412 patients belonging to the SPATAX cohort and 400 patients from the diagnosis laboratory of the Pitié-Salpêtrière Hospital).
DNAs libraries were prepared through KAPA library preparation kit (KAPA Biosystems). The panel included the target regions probes corresponding to all coding exons belonging to 70 HSP genes and was designed by Roche-NimbleGen (SeqCap EZ). The DNA sequencing was realized using the MiSeq or NextSeq sequencers (Illumina). Alignment and calling of variants were performed by BWA and GATK, respectively, and search for rearrangements was done by cover analysis in cases without obvious variants for the search series. A dedicated pipeline from GenoDiag was used for the diagnosis cohort. Variants were filtered and prioritized, then verified through Sanger sequencing on patients and on other family members, in order to establish the segregation patterns.
A gene responsible for the disease phenotype was identified in 35.2% of the patients overall analysed in the SPATAX cohort. For 44,4% of the patients, no pathogenic variant could be detected. One or more variants with unknown significance was identified among 20,4% of the cohort; in these cases the actual knowledge regarding the gene involved did not allow to draw a conclusion regarding a possible pathogenic effect, and therefore their role in HSP onset. Comparable results were recorded in the diagnosis cohort, including the identification of the gene responsible for the pathology in 28% of cases, a smaller frequency due to the broader phenotypic spectrum.
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Among the most frequently mutated genes in naïve cases, there were mutations in SPAST, SPG7 and KIF1A. Interestingly, we identified a series of 60 index patients carrying heterozygous variants in the motor domain of KIF1A inherited in a dominant pattern or de novo which contrast with the classical recessive transmission mode of this gene in SPG30. This form promises to be very frequent.
Through the coupling of targeted capture and next generation sequencing it was possible to increase the molecular diagnostic rate if compared to more classical strategies based on decision tree and followed by genetic analysis according to the transmission modes. The sequencing of our 812 patients cohort therefore show the importance of testing the same set of genes in patients with different transmission patterns, allowing the detection of multiple and unexpected transmission pathways.
Abstract 77 _ Unusually severe and rapid cerebellar ataxia associated with SACS variants Mansat C.1, Coarelli G.2,3, Burglen L.4, Goizet C5., Vicart S.6, Durr A2,3. 1Département de génétique clinique, University Hospital Pitié-Salpêtrière, Paris, France 2Sorbonne Université, Institut du Cerveau et de la Moelle épinière (ICM), AP-HP, Paris, France 3Inserm, CNRS, University Hospital Pitié-Salpêtrière, Paris, France 4Centre de Référence Maladies Rares »Malformations et Maladie Congénitales du Cervelet », département de génétique, Hôpital Trousseau, Paris, France 5 Centre de Référence Neurogénétique, University Hopsital of Bordeaux, and Laboratoire MRGM, INSERM U1211, Univ. Bordeaux, Bordeaux, France 6Département de Neurologie, Pavillon Paul Castaigne, Hôpital Salpêtrière, Paris, France
Introduction
SACS gene variants are responsible for autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). It is a slowly progressive neurodegenerative disease, generally of early childhood, manifesting as a triad of symptoms: cerebellar ataxia, pyramidal syndrome and peripheral axonal-demyelinating sensorimotor neuropathy. Electrophysiological anomalies, fundoscopy and brain MRI are highly suggestive of ARSACS. However, atypical presentations and novel variants in the SACS gene are frequently identified.
Clinical presentation
We report a 20 years old French woman seen at the Pitié-Salpêtrière University Hospital in Paris. Parents were not related. Gait impairment followed by dysarthria was first noticed at age 18. Cerebellar ataxia was secondarily associated with marked pyramidal syndrome and decreased vibration sense at ankles, without muscle wasting. The progression was rapid, requiring a walking device after two years of evolution, with a SARA score of 18.5/40 (+ 5 points/year). Autoimmune, carential, infectious and metabolic aetiologies were excluded. Brain MRI showed marked cerebellar and pons atrophy. CSF sampling and electrophysiology were normal. FXN and autosomal dominant spinocerebellar ataxia genes due to polyglutamine expansion were negative. Next generation sequencing found two heterozygous variants in the SACS gene: c.1373C>T/p.Thr458Ile, already reported as pathogenic and the novel variant c.10841A>G/p.Glu3614Gly. Functional tests in patient’s fibroblasts searching for impaired mitochondrial network are ongoing.
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Discussion
This case-report broadens the phenotypical presentation of ARSACS, the most common recessive spastic ataxia. This gene should be investigated also in patients with atypical clinical and paraclinical presentation, including later age at onset and rapid progression.
Abstract 78 _ Dominant negative heterozygous mutation in Erlin2 prevents degradation of IP3 receptors and is responsible for hereditary spastic paraplegia 37 Giovanni Stevanin1,2, Agnès Rastetter1,2, Typhaine Esteves1,2, Sylvain Hanein1,2, Christel Depienne1, Alexis Brice1, Alexandra Durr1, Frédéric Darios1
1.Institut du Cerveau et de la Moelle épinière (ICM), INSERM, CNRS, Assistance Publique-Hôpitaux de Paris (AP-HP), Sorbonne Université, Pitié-Salpêtrère University Hospital, Paris, France 2.Ecole Pratique des Hautes Etudes (EPHE), Paris Sciences et Lettres (PSL) Research University, Neurogenetics Group, Paris, France
Introduction: Erlin 2 is an endoplasmic reticulum protein mediating the degradation of IP3 receptors. Autosomal recessive or dominant mutations of Erlin2 have been implicated in complex motor neuron diseases with cognitive impairment, including hereditary spastic paraplegia SPG18. Materials and Methods: We analysed the exome sequencing of four patients of a large family with autosomal dominant spastic paraplegia significantly linked to the SPG37 locus, a chromosomal region containing the Erlin2 gene and overlapping the SPG18 locus. Fibroblasts of an affected patient and of a sex and age-matched control were subjected to an agonist of IP3 receptors to analyse their degradation by the proteasome. Fibroblasts were also transfected with siRNAs targeting the pathological allele to observe the reversal of the phenotype. Results: We identified the heterozygous c.194C>T (p.T65I) missense variant in Erlin2 segregating in the family. Mutated and wild type alleles were expressed at the same level in fibroblasts. Compared to controls, IP3 receptors degradation was slower in mutated fibroblasts, suggesting a degradation process blockage. To test the hypothesis that the variant acts as a dominant negative, we specifically downregulated the p.T65I variant using siRNA. While Erlin2 levels remained normal in control lines, a 50% dowregulation of the p.T65I allele was observed in the SPG37 line with reduced degradation capacities of IP3 receptors. Conclusion: We report that a heterozygous missense variant of Erlin2 accounts for SPG37 through a dominant negative effect on the IP3 receptors degradation in vitro.
Abstract 80 _ The lack of spatacsin (SPG11) disrupts postnatal synaptogenesis in mouse Liriopé Toupenet (1), Typhaine Esteves (1), Julien Branchu (1), Frédéric Darios (1), Giovanni Stevanin (1), Khalid El Hachimi (1). (1) Inserm U1127, CNRS UMR7225, UPMC UMR_S975, Institut du Cerveau et de la Moelle Epiniere, Paris, France
Hereditary spastic paraplegias are neurodegenerative motor neuron diseases characterized by rigidity and paralysis of the lower limbs. Spastic paraplegia type 11 (SPG11) is the most common recessive autosomal paraplegia, accounting for 21% of autosomal recessive forms.
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The severe motor conditions were often associated with cognitive disorders including mental retardation (low IQ <70), short-term memory impairment. We have generated a SPG11 knockout mouse which mimics the clinico-pathological features of the human disease. The mice have a motor deficit and a cognitive deficit resulting in early spatial and emotional memory disorders (Branchu et al., 2017). We investigated, the cellular basis of this cognitive deficit. We used photonic and electron microscopies on Epon included hippocampus. We analysed the post-natal developmental stages of hippocampus of Spg11-/- v/v Spg11+/+mice at P10, P14, P20 and P60 since the memory impairment manifest early. First, the number of pyramidal neurons in CA1 area of the hippocampus was quantified and the thickness of the SR measured. Then, with electronic microscopy, we quantified the synapses of the SR in CA1 area. Finally, to complete the study, we realized a morphological characterisation of the dendritic spines. We showed: I) Neither modification on neuronal density of CA1 nor on the thickness of SR; II) Decreased number of synapses in the SR of the CA1. No developmental alteration of the hippocampus was observed, but the study highlights a clear delay of synaptogenesis in Spg11-/- mice which reach 20% in comparison with Spg11+/+mice. Further studies could decipher the molecular mechanisms of this synaptogenesis delay.
Abstract 81 _ Several phenotypes one gene: AFG3L2, when genetics garble the rules. Cecilia Mancini (1), Grace Yoon (2), Amanda Carnevale (3), Marta Ferrero (1) and Alfredo Brusco(1,4).
1. Department of Medical Sciences, University of Torino, Torino, Italy 2. Division of Clinical and Metabolic Genetics, Department of Paediatrics, The Hospital for Sick Children, University of
Toronto, Toronto, Ontario, Canada 3. Division of Neurology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto,
Ontario, Canada 4. Medical Genetics Unit, Città della Salute e della Scienza University Hospital, Torino, Italy
Spastic ataxia-5 (SPAX5) is an autosomal recessive disorder, characterized by early-onset neurodegeneration, myoclonic epilepsy, dystonia, ptosis and oculomotor apraxia. The causative gene is AFG3L2, encoding a protein subunit that forms the m-AAA protease (matrix-ATPase associated with diverse cellular activities), a multimeric complex bound to the inner mitochondrial membrane, crucial component of the mitochondrial protein quality control system. Heterozygous mutations of AFG3L2 cause the autosomal dominant form spinocerebellar ataxia type 28 (SCA28). So far, only four SPAX5 patients have been described, reporting a huge clinical variability. Here, we report the first compound heterozygous SPAX5 patient reporting two in-trans variants in the AFG3L2 gene: c.1847A>G (p.Y616C) and c.1976C>T (p.A659V) (maternally and paternally inherited, respectively). The patient was brought to medical attention at eight months of age when he was unable to sit unsupported; he had oculomotor apraxia and developed myoclonic seizures at age 18 months. He showed epilepsia partialis continuans (EPC) starting at age 2.5 years. As already shown in the literature, SPAX5 patient parents did not show any sign of neurodegeneration nor oculomotor signs, despite carriers of an AFG3L2 mutant allele. We documented the mitochondrial phenotype of patient-derived primary fibroblasts, showing a slightly reduced mitochondrial membrane potential in compound-heterozygotes patient compared to healthy controls and an increased SOD2 level, suggesting an increased oxidative stress in SPAX5 cells. Muscle biopsy-derived mitochondrial enzyme analysis revealed mild
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Complex I deficiency. No alteration in mitochondrial network was remarkable, showing patient cells having mitochondrial axes length comparable with controls fibroblasts. In conclusion, we describe the first compound heterozygous SPAX5 patient, carrying one variant in exon 16 of AFG3L2, the SCA28 mutational hotspot. Our data further corroborate the idea that mutations in AFG3L2 may have a hypomorphic and variable effect, linked to the affected residual and related number of functional (or partially functional) m-AAA hexamers able to be formed.
Abstract 82 _ IRF2BPL-associated spastic-ataxic neurodegeneration is characterized by DRPLA-like pathology and polyglutamine inclusions Sunita Venkateswaran1,, Jean Michaud1, Yoko Ito1, Evan Lewis2, Michael Geraghty1, David A Dyment1, Care4Rare, Kym Boycott1, Kristen Kernohan1
1. Children’s Hospital of Eastern Ontario Research Institute, Ottawa, Canada 2. Neurology Centre of Toronto, Toronto, Canada
Background: IRF2BPL mutations have been recently been found in patients with neurological regression and developmental epileptic encephalopathy. Here we report a 10 year old patient with early onset spastic-ataxic neurodegeneration and epilepsy whose diagnosis was guided by post-mortem neuropathological findings consistent with dentatorubral- pallidoluysian atrophy (DRPLA). He was negative for the expansion in the ATN1 gene however, whole exome sequencing revealed a de novo pathogenic mutation in IRF2BPL. IRF2BPL is an intronless gene with a polyalanine (polyA) and polyglutamine (polyQ) tract.
Findings: Post-mortem neuropathological findings were reported as most consistent with DRPLA with cardinal features of neuronal loss and gliosis involving the globus pallidus, predominantly pars externa, and the dentate nucleus with secondary involvement of their projections, the subthalamic nucleus and red nucleus. Grumose degeneration of the dentate nucleus, also considered characteristic of DRPLA, was present. The anti-polyglutamine IC2 antibody revealed small intranuclear inclusions in a moderate number of neurons of the CA4 sector of the hippocampi and rare intranuclear inclusions in the substantia nigra and red nuclei.
Conclusion: Important post-mortem neuropathological findings consisted of ubiquitinated intranuclear inclusions, largely in neurons, particularly numerous in the hippocampi, cerebral neocortex and dentate nuclei of the cerebellum. This is a pathological hallmark of polyglutamine expansion diseases. We propose that that mutations in IRF2BPL may be
responsible for DRPLA-type 2, a spastic-ataxic neurodegenerative epileptic encephalopathy.
Figure 1 A. Part of the CA4 sector of the hippocampus showing severe loss of neurons and gliosis (HPS, 100x). B. p62 immunostaining of the subiculum showing several neurons with intranuclear inclusions (p62, 400x). Insert: Intranuclear inclusion in one oligodendrocyte (arrow) (p62, 400x). C. Anti-polyglutamine, N-terminus, clone 5TF1-1C2 showing positive inclusions in some neurons (IC2, 600x). D. Globus pallidus with loss of neurons and reactive gliosis (HPS, 200x).
69
List of the SPATAX Network members
Web links to the SPATAX network: https://spatax.wordpress.com/
https://www.facebook.com/SPATAX-186083254777101/
Brain and Spine Institute (ICM)
DURR Alexandra (coordinator)
STEVANIN Giovanni (co-coordinator)
BRICE Alexis
DARIOS Frédéric
FORLANI Sylvie (DNA and Cell bank, ICM)
ICM INSERM U1127 Sorbonne Université UMR S 1127
CNRS UMR7225
Pitié-Salpêtrière Hospital
Paris, France
Other French members
Site Pitié-Salpêtrière
BANNEAU Guillaume (UF de Neurogénétique
Moléculaire et Cellulaire)
CAZENEUVE Cécile (UF de Neurogénétique
Moléculaire et Cellulaire)
CHARLES Perrine (Consultation de Génétique Clinique)
DUYCKAERTS Charles
FONTAINE Bertrand
France
AZULAY Jean-Philippe (Service de Neurologie et
Pathologies du Mouvement Hôpital d’Adultes de la
Timone, Marseille)
BOESFPLUG-TANGUY Odile (Service de neurologie
pédiatrique et des maladies métaboliques – Hôpital
Robert Debré, Paris & UMR Inserm 931 Faculté de
Médecine, Clermont-Ferrand)
BURGO Andrea (Laboratoire Structure-activités des
biomolécules, Inserm 829, Université d’Evry-Val
d’Essonne)
GOIZET Cyril (Consultation de Neurogénétique CHU de
Bordeaux, Hôpital Pellegrin, Bordeaux)
HANNEQUIN Didier (Unité de Génétique Clinique
Hôpital Charles Nicolle, Rouen)
HAZAN Jamilé (INSERM U952 Université Pierre et
Marie Curie, Paris)
KOENIG Michel (Laboratoire de génétique moléculaire,
IURC - Institut Universitaire de Recherche Clinique, 641
Avenue du Doyen Gaston Giraud,
34093 Montpellier cedex 5)
LABAUGE Pierre (Service de Neurologie Hôpital
Caremeau, Place du Professeur Debré, Nîmes)
MARELLI Cecilia (Service de Neurologie
Comportementale et CMRR, CHRU Gui de Chauliac, 80,
av. A. Fliche, 34295 Montpellier cedex 05)
N’GUYEN Karine (Département de Génétique Médicale
Unité de Génétique Clinique, Hôpital d’Enfants de la
Timone, Marseille)
RODRIGUEZ Diana (Service de Neuropédiatrie et
Pathologie du Développement Hôpital Armand
Trousseau-La Roche-Guyon, Paris)
VERNY Christophe (Service de Génétique Département
de Neurologie, Unité Charcot, CHU d’Angers, Angers)
70
Others by country
Algeria
BELARBI Soraya (Service de Neurologie CHU
Mustapha, Place du 1er Mai, Algiers)
HAMRI Abdelmadjid (Service de Neurologie Hôpital
Benbadis, Constantine)
TAZIR Meriem (Service de Neurologie CHU Mustapha,
Place du 1er Mai, Algiers)
Austria
BOESCH Sylvia (Medical University, Innsbruck,
Austria)
Belgium
PANDOLFO Massimo (Service de Neurologie
Université Libre de Bruxelles, Hôpital Erasme, Route de
Lennik 808, 1070 Brussels)
Brazil
Laura Jardim (Department of Internal Medicine, Faculty
of Medicine, Federal University of Rio Grande do Sul)
Bulgaria
GUERGUELTCHEVA Velina (Clinic of Neurology,
University Hospital Alexandrovska, Sofia, Bulgaria)
TOURNEV Ivalo (Clinic of Neurology, University
Hospital Alexandrovska, Sofia, Bulgaria)
Colombia
PEDRAZA LINARÈS Olga Lucia (Departamento
Neurociencias Faculté de Médecine, Cra. 18 No. 88-17
(Cons. 305), FUCS, HIUSJ, Bogota)
Denmark
NIELSEN Jørgen E. (Department of Medical Genetics
Section of Neurogenetics, The Panum Institute,
University of Copenhagen)[email protected]
SVENSTRUP Kirsten (Section of Neurogenetics, The
Panum Institute, University of Copenhagen)
Egypt
ZAKI Maha (Clinical Genetics Department, Human
Genetics and Genome Research Division, National
Research Centre, Cairo)
Germany
BAUER Peter (Institute of Medical Genetics and
Applied Genomics, University of Tübingen, Tubingen)
SCHÖLS Lüdger (Department of Neurology and Hertie-
Institute for Clinical Brain Research University of
Tübingen)
SCHÜLE Rebecca (Department of Neurology and
Hertie-Institute for Clinical Brain Research University of
Tübingen)
Israel
LOSSOS Alexander (Department of Neurology
Hadassah-Hebrew University Hospital, Ein Kerem,
Jerusalem 91120)
Italy
BASSI Maria-Teresa (Eugenio Medea, Bosisio Parini)
BASSO Manuela (Center for Integrative Biology
(CIBIO), University of Trento, Povo)
BERTINI Enrico (Molecular Medicine & Dept. of
Neurosciences Osp. Bambino Gesù, Roma)
BRUSCO Alfredo (Department of Genetics Biology and
Biochemistry University of Turin, Torino)
CASALI Carlo (Medico-Surgical Sciences and
Biotechnologies, Sapienza University of Rome)
71
CASARI Giorgio (Vita-Salute San Raffaele University
and Human Molecular Genetics Unit San Raffaele
Scientific Institute, DIBIT, Milano)
CRISCUOLO Chiara (Clinica Neurologica, Università
Degli Studi Di Napoli Federico II, Napoli)
FILLA Alessandro (Dipartimento Di Scienze
Neurologiche Clinica Neurologica, Università Degli
Studi Di Napoli Federico II, Napoli)
ORSI Laura (Department of Neuroscience and Mental
Health- Neurological Clinic 1, Universitary Hospital
Torino)
SANTORELLI Filippo M. (Molecolare e Malattie
Neuromusculari, Neurogenetics Laboratory UOC
Neurodegenetic e Medicina, Istituto di Neuropsichiatria
Infantile (INPE), IRCCS Fondazione Stella Maris,
Calambrone)
VALENTE Enza Maria (Istituto di Genetica Medica «
CSS Mendel » Viala Regina Margherita 261, Roma)
VAVLA Marinela (IRCCS Eugenio Medea Associazione
La Nostra Famiglia, Conegliano)
VAZZA Giovanni (Università degli Studi di Padova,
Italy)
Lebanon
MEGARBANE André (Unité de génétique Médicale
Université Saint-Joseph Faculté de Médecine, Campus
des Sciences Médicales,
Rue de Damas, BP 11-5076 Riad El Solh, 1107 2180
Beirut)
Morocco
BENOMAR Ali (Service de Neurologie B Laboratoire de
Neurogénétique, Hôpital des Spécialités, Rabat Instituts,
Rabat)
The Netherlands
KREMER Berry (H.P.H. Department of Human
Genetics Radboud University Nijmegen Medical Centre,
Radboud)
VAN ROON-MOM Willeke (Leiden University Medical
Center)
New Zealand
ROXBURGH Richard (Neurology Department,
Auckland city hospital)
Norway
ERICHSEN Anne Kjersti (Department of Neurology
Ullevål University Hospital, Oslo)
TALLAKSEN Chantal (Department of Neurology
Ullevål University Hospital, Oslo)
Portugal
ALONSO Isabel (UniGENe, IBMC University of Porto,
Porto)
COUTINHO Paula (Serviço de Neurologia Hospital S.
Sebastião, Santa Maria da Feira)
LOUREIRO José Léal (Serviço de Neurologia Hospital
S. Sebastião, Santa Maria da Feira)
SEQUEIROS Jorge (UniGENe, IBMC University of
Porto, Porto)
Saudi Arabia
SALIH Mustapha (A.M. Department of Pediatrics
(39) College of Medicine and KKUH, King Khalid
University Hospital, PO Box 2925, Riyadh 11461)
Serbia
72
KOSTIC Vladimir S (Institute of Neurology Clinical
Centre of Serbia, str. Dr. Subotica 6A, Belgrade 11000)
Spain
ROUCO AXPE Idoia (BioCruces Health research center
institute, Barakaldo)
Sudan
ELSAYED Liena (Dept of Biochemistry, Faculty of
Medicine, University of Khartoum)
Sweden
PAUCAR ARCE Martin (Department of Clinical
Neuroscience, Karolinska University, Stockholm)
Syria
ROUMANI Samir (Service of Neurology PO Box 5764,
Damaseus)
Taiwan
BING-WEN Soong (National University Yang-Ming,
Taipei)
Tunisia
BOUKHRIS Amir (Unité de Neurogénétique Service de
Neurologie, Hôpital Habib Bourguiba, Sfax)
MHIRI Chokri (Unité de Neurogénétique Service de
Neurologie, Hôpital Habib Bourguiba, Sfax)
Turkey
KARABAY Arzu (Genetics Research center, Istanbul
Technical University Molecular Biology-Biotechnology
and Genetics Research center, Ayazaga campus, Maslak, Istanbul)
The United Kingdom
O’KANE Cahir (Department of Genetics, University of
Cambridge, Cambridge) [email protected]
OLIVA Megan (Department of Genetics, University of
Cambridge, Cambridge) [email protected]
REID Evan (Department of Medical Genetics University
of Cambridge, Cambridge)
SURAN Nethisinghe (UCL Institute of
Neurology London) [email protected]
WARNER Thomas (University Department of Clinical
Neurosciences Royal Free and University College
Medical School, University College, London)
WOOD Nicholas (Neurogenetics, Institute of
Neurology University Department of Clinical
Neurology, The National Hospital, Queen Square,
London)
73
List of the Ataxia Study Group- ASG-members
www.ataxia-study-group.net/
ALONSO Isabel
Instituto de Biologia Molecular e Celular
University of Porto
Porto, Portugal
BOESCH Sylvia
Department of Neurology
University of Innsbruck
Innsbruck, Austria
BÜRK Katrin
Department of Neurology
Philipps-University of Marburg
Marburg, Germany
CASALI Carlo
Department of Medico-Surgical Sciences and
Biotechnologies
University of Rome ‘‘Sapienza’
Polo Pontino, Latina, Italy
COUTINHO Paula
UnIGENe and Centro de Genetica Preditiva e Preventiva,
Institute for Molecular and Cell Biology, Universidade
do Porto
Porto, Portugal
DIDONATO Stefano
Divisione di Biochimica e Genetica
Istituto Nazionale Neurologico Carlo Besta - IRCCS
Milan, Italy
DURR Alexandra
Department of Genetics
ICM / Salpêtrière Hospital – Sorbonne Université
Paris, France
FARUQ Mohammed (Dehli)
Institute of Genomics and Integrative Biology
Delhi, India
FESTENSTEIN Richard
Clinical Professor of Molecular Medicine Department of
Medicine
Imperial College London
London, UK
FILLA Alessandro
Dipartimento Di Scienze Neurologiche
Clinica Neurologica, Università Degli Studi Di Napoli
Federico II
Napoli, Italy
GIORDANO Ilaria Anna
Klinik und Poliklinik für Neurologie
Universitätsklinikum Bonn Sigmund-Freud- Bonn,
Germany
GIUNTI Paola
Department of Molecular Neuroscience
Institute of Neurology, Queen Square
University College London
London, UK
INFANTE Jon
Department of Neurology
University Hospital “Marqués de Valldecilla,”
Santander, Spain
JACOBI Heike
Department of Neurology
University Hospital of Bonn
Bonn, Germany
KANG Jun-Suk
Department of Neurology
University of Frankfurt
Frankfurt am Main, Germany
KLOCKGETHER Thomas
Department of Neurology
University Hospital of Bonn
Bonn, Germany
KOENIG Michel
INSERM U964
Institut de Génétique et de Biologie Moléculaire et
Cellulaire (IGBMC)
Illkirch, France
KREMER Berry
Department of Neurology
University Medical Centre Groningen
Groningen, The Netherlands
74
KRYSA Wioletta
Zakład Genetyki
Instytut Psychiatrii i Neurologii w Warszawie
Warszawa, Poland
MACIEL Patricia (Minho)
Neurogeneetics
Universidade do Minho,
Minho,Portugal
MANTUANO Elide
Laboratorio di Neurogenetica
Istituto di Farmacologia Traslazionale
CNR - Dipartimento di Medicina
Roma, ITALY
MARIOTTI Caterina
Department of Biochemistry and Genetics
Fondazione-IRCCS
Istituto Neurologico Carlo Besta
Milan, Italy
MATILLA DUEÑAS Antoni
Investigator of the Spanish National Health System
Department of Neuroscience Health Sciences Research
Institute Germans Trias i Pujol (IGTP) Universitat
Autònoma de Badalona, Spain
MELEGH Bela
Department of Medical Genetics and Child Development
University of Pécs
Pécs, Hungary
MINNEROP Martina
Department of Neurology,
University Hospital Bonn,
Bonn, Germany
MÜNCHAU Alexander
Institute of Neurogenetics
University of Lübeck
Lübeck, Germany
PANDOLFO Massimo
Service de Neurologie
Université Libre de Bruxelles, Hôpital Erasme
Brussels, Belgium
PINTO BASTO Jorge
Instituto de Biologia Molecular e Celular
University of Porto
Porto, Portugal
PUCCIO Hélène
INSERM U964
Institut de Génétique et de Biologie Moléculaire et
Cellulaire (IGBMC)
Illkirch, France
RAKOWICZ Maria
Department of Clinical Neurophysiology Institute of
Psychiatry and Neurology
Warsaw, Poland
RIESS Olaf
Department of Medical Genetics
University of Tübingen
Tübingen, Germany
RINALDI Carlo
Dipartimento Di Scienze Neurologiche
Clinica Neurologica, Università Degli Studi Di Napoli
Federico II
Napoli, Italy
ROLA Rafal
Institute of Psychiatry and Neurology
Warsaw, Poland
RUEB Udo
Dr. Senckenberg Chronomedical
Institute, Goethe-University
Frankfurt/Main, Germany
SAFRANI Eniko
Pecs, Hungry
SCHMITZ-HUEBSCH Tanja
Department of Neurology
University Clinic Bonn
Bonn, Germany
SCHÖLS Lüdger
Department of Neurology and Hertie-Institute for
Clinical Brain Research
University of Tübingen
Tübingen, Germany
SCHULZ Jörg B.
75
Department of Neurology
University Hospital Aachen
Aachen, Germany
SEQUEIROS Jorge
Instituto de Biologia Molecular e Celular
University of Porto
Porto, Portugal
STRICKER Sarah
Klinik und Poliklinik für Neurologie University
Medicine Berlin
Berlin, Germany
SULEK Anna
Zakład Genetyki
Instytut Psychiatrii i Neurologii w Warszawie
Warszawa, Poland
SYNOFZIK Matthis
Department of Neurodegeneration
Hertie Institute for Clinical Brain Research and Centre of
Neurology
Tübingen, Germany
TALLAKSEN Chantal
Department of Neurology
Ullevål University Hospital
Oslo, Norway
TARONI Franco
SOSD Genetics of Neurodegenerative and Metabolic
Diseases
Fondazione IRCCS
Istituto Neurologico “Carlo Besta,”
Milan, Italy
TIMMAN-BRAUN Dagmar
Department of Neurology
University Hospital of Essen
Essen, Germany
TROTTIER Yvon
Département de neurobiologie et génétique
Institut de Génétique et de Biologie Moléculaire et
Cellulaire (IGBMC)
Illkirch, France
VAN DE WARRENBURG Bart
Department of Neurology
Donders Centre for Neuroscience
Radboud University Nijmegen Medical
Nijmegen, the Netherlands
VENEZIANO Liana
Institute of Translational Pharmacology
C.N.R.
Rome, Italy
WUELLNER Ullrich
Department of Neurology
University of Bonn
Bonn, Germany
ZAREMBA Jacek
Zakład Genetyki
Instytut Psychiatrii i Neurologii w Warszawie
Warszawa, Poland
ZIANNI Ginevra
Molecular Medicine & Dept. of Neurosciences
Osp. Bambino Gesù
Rome, Italy
76
List of the PREPARE consortium members
Project Coordinator
Matthis Synofzik_Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany
Consortium Partners (PI &Co-PIs)
Bart van de Warrenburg & Annette Schenck Radboud University Medical Center (Nijmegen, The
Netherlands)
Giovanni Stevanin & Alexandra Durr INSERM / Paris University (France)
Helene Puccio & Mathieu Anheim &Michel Koenig Institut de Genetique et de Biologie Moleculaire et
Cellulaire (Illkirch, France)
Bernard Brais & Cynthia Gagnon McGill University (Montreal, Canada)
Filippo Santorelli IRCCS Fondazione Stella Maris (Pisa, Italy)
Hasmet Ayhan Hanagasi & Ebba Lohmann University Istanbul (Istanbul, Turkey)
Associated partners
Paola Giunti University College London (London, Great Britain)
Peter de Jonghe University of Antwerp (Antwerp, Belgium)
Rita Horvarth & Patrick Chinnery Newcastle University (Newcastle, Great Britain)
Stephan Zuchner University of Miami (Miami, USA)
Faycal Hentati National Institute of Neurology (Tunis, Tunisia)
Nazli Basak _Koç University (Istanbul, Turkey)
Enrico Bertini Bambino Gesu' Children's Research Hospital (Rome, Italy)
77
List of participants to the meeting
ABD ALLAH Amal University of Khartoum, Qasr Street, Sudan [email protected] ALLISON Rachel University of Cambridge, CIMR, Cambridge, United Kingdom [email protected] AMPROSI Matthias Medical University Innsbruck, Innsbruck, Austria [email protected] ANGELINI Chloé CHU de Bordeaux, Bordeaux [email protected] AVILA-FERNANDEZ Almudena Fundacion Jiménez Diaz University Hospital, Madrid, Spain [email protected] AZZOUZ Mimoun University of Sheffield, Sheffield, United Kingdom [email protected] BADERNA Valentina San Raffaele Scientific Institute, Milan, Italy [email protected] BALAGUE Eudald Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain [email protected] BALBO Ilaria University of Torino, Torino, Italy [email protected] BARBIER Mathieu ICM Institute, Paris, France [email protected] BASAK A. Nazl Koc University, Istanbul, Turkey [email protected] BASSI Maria Teresa Associazione la Nostra Famiglia - IRCCS E. Medea, Bosisio Parini (Lc), Italy [email protected]
BENARD Jean ASL-HSP France, France [email protected] BISCHOFF Vincent DYNACURE, France [email protected] BOESCH Sylvia Universitätsklinik für Neurologie, Innsbruck, Austria [email protected] BOESPFLUG-TANGUY Odile Hopital Robert Debré neuropédiatrie UMR1141, Paris, France [email protected] BŒUF Hubert CSC, France [email protected] BONIFACINO Juan NIH, Bethesda, USA [email protected] BRAIS Bernard McGill University, MONTREAL, CANADA [email protected] BREZA MARIANTHI National and Kapodistrian University of Athens, Athens, Greece [email protected] BRICE Alexis ICM Institute, Paris, France [email protected] BRUSCO Alfredo University of Torino, Torino, Italy [email protected] CAVACA Isabel Addapters Org Cure AP4, Portugal [email protected] CHAPPLE Paul Queen Mary University of London, London, United Kingdom [email protected]
78
CHIOCCIOLI ALTADONNA Ginevra University of London, London, United Kingdom [email protected] CHRISTENSEN Lars The Danish association for Ataxia / HSP, Denmark [email protected] CORRAL-JUAN MARC Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain [email protected] COUPRY Isabelle INSERM U1211 Laboratoire MRGM, Bordeaux, France [email protected] DARIOS Frédéric ICM Institute, Paris, France [email protected] DARIVA MACHADO Gustavo Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil [email protected] DAVIES Alexandra Max Planck Institute of Biochemistry, Martinsried, Germany [email protected] DAVOINE Claire-Sophie ICM Institute, Paris, France [email protected] DE GIULI Valeria University of Brescia, Brescia , Italy [email protected] DEL BONDIO Andrea San Raffaele Scientific Institute, Milan , Italy [email protected] DELL'ERA Valentina University of Brescia, Brescia , Italy [email protected]
DEPIENNE CHRISTEL Institut für Humangenetik, UK Essen, Essen, Germany [email protected] DI BELLA Daniela Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Itlay [email protected] DINIZ Fabricio University Of Campinas, Campinas, Brazil [email protected] DURAND Christelle INSERM U1211 Laboratoire MRGM, Bordeaux, France [email protected] DURR Alexandra ICM Institute, Paris, France Department of Genetics_Pitié-Salpêtrière Hospital Paris, France [email protected] EIDHOF Ilse Radboud University, Nijmegen, The Netherlands [email protected] ELSAYED Liena University of Khartoum, Qasr Street, Sudan [email protected] ELTARAIFEE Esraa University of Khartoum, Qasr Street, Sudan [email protected] ESTEVES Typhaine ICM Institute, Paris, France [email protected] EVERS Melvin uniQure, AMSTERDAM, The Netherlands [email protected] EWENCZYK Claire Genetic departement, Paris, France [email protected]
79
FABER Jennifer DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany [email protected] FILLA Alessandro Federico II university, Napoli, Italy [email protected] FINK John University of Michigan, Michigan, USA [email protected]
FISCHER Gerald EuroHSP, Austria [email protected] FJERDINGSTAD Hege Brincker Domus Medica, Oslo, Norway [email protected] GALATOLO Daniele IRCCS Fondazione Stella Maris, Pisa, Italy [email protected] GAN-OR Ziv McGill University, Montreal, Canada [email protected] GELLERA Cinzia Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Itlay [email protected] GERBILD John Ataksi/HSP Danmark, Denmark [email protected] GEURTS Alexandre Radboud University, Nijmegen, The Netherlands [email protected] GINGLINGER Emmanuelle GHRMSA , Mulhouse, France [email protected]
GOIZET Cyril CHU Bordeaux , Université Bordeaux, Bordeaux, France [email protected] GRUNDMANN-HAUSER Kathrin Institute of medical genetics and applied genomics, Tuebingen, Germany [email protected] GUILLOT-NOEL Lena ICM Institute, Paris, France [email protected] GUISSART Claire CHU Montpellier, Montpellier , France [email protected] HACHE Antoine IGBMC, Illkirch, France [email protected] HALLEB Yosra Laboratoire de Génétique Moléculaire Institut Universitaire de Recherche Clinique, Montpellier, France [email protected] HILAB Rania ICM Institute, Paris, France [email protected] HIRST Jennifer University of Cambridge, Cambridge, United Kingdom [email protected] HOMMERSOM Marina Radboudumc University, Nijmegen, The Netherlands [email protected] HOULDEN Henry UCL, London, United Kingdom [email protected] HOXHA Eriola University of Torino, Torino, Italy [email protected]
80
HUANG Miaozhen University of Groningen, Groningen, The Netherlands [email protected] HURMIC Hortense ICM Institute, Paris, France [email protected] INDELICATO Elisabetta Innsbruck Medical University Innsbruck, Austria [email protected] JACOBI Heike University Hospital Heidelberg, Heidelberg, Germany [email protected] KESAVAN Maheswaran University college London, London, United Kingdom [email protected] KIEFFER Félicie UCA, Rombach Le Franc, France [email protected] KLEBE Stephan Department of Neurology, University Hospital Essen, Essen Germany [email protected] KLOCKGETHER Thomas German Center for Neurodegenerative Diseases, Bonn, Germany [email protected] KOENIG MICHEL Université de Montpellier, Montpellier, France [email protected] KOUTSIS GEORGIOS National and Kapodistrian University of Athens, Athens, Greece [email protected] LA PIANA Roberta Montreal Neurological Institute, Montreal, Canada [email protected]
LALLEMANT DUDEK Pauline ICM Institute, Paris, France [email protected] LARRIEU Lise CHU de Montpellier Laboratoire de Génétique, Montpellier, France [email protected] LASSERRE Jean-Paul INSERM U1211 Laboratoire MRGM, Bordeaux, France [email protected] LAWRENCE Adam UK HSP Support Group, United Kingdom [email protected] LONGO Fabiana Ospedale San Raffaele, Milan, Italy [email protected] LOUREIRO Joana IBMC, Porto, Portugal [email protected] MAAS Roderick Radboud University Medical Center Nijmegen, NIJMEGEN, The Netherlands [email protected] MAGRI Stefania Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Itlay [email protected] MALTECCA Francesca Ospedale San Raffaele, Milan, Italy [email protected] MANCINI Cecilia University of Torino, Torino, Italy [email protected] MANES Marta Antonia University of Brescia, BRESCIA – Italy [email protected]
81
MANOLARAS Ioannis IGBMC, Illkirch, France [email protected] MANSAT Charlotte Genetic departement, Paris, France [email protected] MARELLI Cecilia CHU Gui de Chauliac, Montpellier, France [email protected] MARIOTTI Caterina U.O.C. Genetica Medica e Neurogenetica, Milan, Italy [email protected] MARTINUZZI Andrea IRCCS Medea Scientific Institute, Conegliano, Italy [email protected] MATILLA-DUENAS ANTONI Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain [email protected] MESSAOUD KHELIFI Mouna FSB - USTHB, Constantine, Algeria [email protected] MESZAROSOVA Anna DNA laboratory Dept. of Child Neurology, Praha, Czech Republic [email protected] MINNEROP Martina Research Centre Juelich / University of Düsseldorf, Juelich , Germany [email protected] MOCHEL Fanny ICM Institute, Paris, France Department of Genetics_Pitié-Salpêtrière Hospital Paris, France [email protected]
MOKKACHAMY CHELLAPANDI Deepika Center for Research and interdisciplinary, Paris, France [email protected] MORALES SAUTE JONAS ALEX Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil [email protected] NAEIJE Gilles Hopital Erasme, université libre Bruxelles, Bruxelles, Belgium [email protected] NANETTI Lorenzo Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy [email protected] NIEWIADOMSKA-CIMICKA Anna Institute of Genetics and Molecular and Cellular Biology (IGBMC)
Illkirch, France [email protected] NISHANI Jeyapalan University of Cambridge, Cambridge, United Kingdom [email protected] OZ Gulin University of Minnesota, Minneapolis, USA [email protected] PAPIN Mélanie ICM Institute, Paris, France [email protected] PARODI Livia ICM Institute, Paris, France [email protected] PAUCAR ARCE MARTIN Karolinska University Hospital, Solna, Sweden [email protected]
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PELLERIN David McGill University, Montreal, Canada [email protected] PETIT Elodie ICM Institute, Paris, France [email protected] PIERGA Alexandre ICM Institute, Paris, France [email protected] PUCCIO Hélène Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch-Graffenstaden, France [email protected] REICH Selina Hertie-Institute for Clincial Brain Research, Tübingen, Germany [email protected] REID Evan University of Cambridge, Cambridge, United Kingdom [email protected] REMMELINK Hermien Muscle diseases the Netherlands and Euro HSP, The Netherlands [email protected] RENAUD Mathilde CHU Nancy, Vandoeuvre Les Nancy, France [email protected] RODGER Catherine CIMR, University of Cambridge, Cambridge , United Kingdom [email protected] ROMANO Lisa Queen Mary University, London, United Kingdom [email protected] ROTIG Agnes IMAGINE, Paris, France [email protected]
ROXBURGH Richard University of Auckland, Auckland, New Zealand [email protected] RYDNING Siri Lynne University of Oslo, Oslo, Norway [email protected] SANCHEZ IVELISSE Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain [email protected] SANTORELLI Filippo IRCCS, Roma, Italy [email protected] SARDINA Francesca IBPM-CNR, Rome, Italy [email protected] SCARLATO Marina Ospedale San Raffaele, Milan, Italy [email protected] SCHMITZ-HÜBSCH Tanja Charité Universitätsmedizin Berlin, Berlin, Germany [email protected] SCHUELE-FREYER Rebecca Hertie Institute for Clinical Brain Resarch, Tübingen, Germany [email protected] SERVELHERE Katiane University Of Campinas, Campinas, Brazil [email protected] SILVEIRA Isabel IBMC, Porto, Portugal [email protected] STEPHAN Zuchner University of Miami, Florida, USA [email protected]
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STEVANIN Giovanni EPHE, ICM institute, Paris, France [email protected] STREGAPEDE Simona Petrucci (Fabricia Stregapede) Ospedale Pediatrico Bambino Gesù, Roma , Italy [email protected] SYNOFZIK Matthis Hertie Institute for Clinical Brain Resarch Tübingen, Germany [email protected] TALLAKSEN Chantal UiO, Oslo, Norway [email protected] TARONI Franco Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Itlay [email protected] TARTAGLIA Giorgia Vi.p.s. ONlus, Italian association for HSP, Italy [email protected] TEMPIA Filippo University of Torino, Torino, Italy [email protected] TETREAULT Martine CRCHUM, Montreal, Canada [email protected] THURGOOD Carina The Maddi Foundation, Halstead, England [email protected]
TRASCHUETZ Andreas Universität Tübingen, Zentrum für Neurologie, Tübingen, Germany [email protected]
VAN DE WARRENBURG Bart Radboud University, NIJMEGEN, The Netherlands [email protected]
VAN GAALEN Judith Radboud University Medical Center, Nijmegen, The Netherlands [email protected] VAN KUILENBURG André Amsterdam UMC, Amsterdam, The Netherlands [email protected] VAN ROON-MOM Willeke Leiden University Medical Center, Leiden , The Netherlands [email protected] VANTAGGIATO Chiara Associazione la Nostra Famiglia - IRCCS E. Medea, Bosisio Parini (LC), Italy [email protected] VAZ Frederic UMC, Amsterdam, The Netherlands [email protected] Venkateswaran Sunita CHEO, Ottawa, Canada [email protected] VERBEEK Dineke University Medical Center Groningen, Groningen, The Netherlands [email protected] VERMEER Sascha UZ Leuven Campus Gasthuisberg, Leuven, Belgium [email protected] VINCENT Lucy MoodMoves Ltd., Paris, France [email protected] VOGEL Adam The University of Melbourne, Parkville, Australia [email protected]
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YAHIA OSMAN MOHAMED Ashraf ICM Institute, Paris, France [email protected] ZLAMALOVA Eliska University of Cambridge, Cambridge, United Kingdom [email protected]
ZANNI Ginevra B. Gesù Children's Hospital, Roma, Italy [email protected]
ZAPPAROLI MANZONI Marina Euro HSP, Italy [email protected]
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Venue to the Get-Together
1 Place Yves Klein 06300 Nice
Friday, September the 20th at 8 p.m.
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SPATAX membership application form
To join the SPATAX network, please fill this membership application form in:
Last name:
First Name:
Email address:
Phone:
Affiliation:
Country:
Reason for joining:
Once you have filled it in, give this application to one of the organization team member
during the meeting or send it by email to [email protected].
Your application will then be reviewed by the SPATAX scientific board.
Sincerely yours,
The SPATAX team
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