& genetic disorders. show the genetic history of a family “genetic family tree“ shows...
TRANSCRIPT
Pedigrees& Genetic Disorders
Show the genetic history of a family
“Genetic Family Tree“
Shows phenotypes one generation to the next
Sometimes shows genotypes from one generation to the next;and sometimes you can figure out the genotype
based on your knowledge of inheritance
What is a Pedigree?
http://nd05.jxs.cz/776/087/f51a5cac71_86805403_o2.png
The Weasley Family Tree
each generation is represented using a Roman Numeral circles are females, squares are males a line connecting two shapes indicated a mating shaded in areas indicate an individual affected by the
trait
Pedigree Example FF= Free hanging earsFf= Free hanging earsff= Attached ears
Ff Ff
FfFfff
ff
FFFf
FfFF FF FF Ff
What do you see?
Pedigree Example
Pedigrees tell the phenotypic/genotypic story:◦ Who bred with who? (i.e. Any new traits
introduced?)◦ What was the relationship between relatives?
(i.e. Third cousins once removed)◦ What traits were passed on? (i.e. Hanging ears or
Sickle Cell Anemia)
So who would cares?
Who cares about pedigrees?
A genetic disorder is a disease that is caused by an abnormality in an individual's DNA. Abnormalities can range from a small mutation in a single gene to the addition or subtraction of an entire chromosome or set of chromosomes. (The University of Utah, 2013)
What is a genetic disorder?
Common Misconception Alert!
Genetic disorders are all
inherited.
– NOT TRUE!
Level 1: Single Gene Disorders◦ Mutation of a single gene cause protein to be
altered or deleted
Level 2: Chromosome Abnormalities◦ Entire chromosomes or large segments are
deleted, duplicated or altered
Level 3: Multifactorial Disorders◦ Mutations in multiple genes, often coupled with
environmental factors
Levels of Genetic Disorders
(The University of Utah, 2013)
(The University of Utah, 2013)
Factors of Genetic Disorders
Environmental Stress Diet Physical/Mental Abuse Drugs and Alcohol Exposure to Radiation,
Pathogens, Toxins and Chemicals
E.g. A person exposed to head injuries may be more likely to develop Alzheimer’s.
Heredity
Family Medical History
◦ 1st, 2nd and 3rd generation
◦ Skipped Generations
◦ Carriers Autosomal Dominant/ Recessive X-Linked Dominant/ Recessive Mitochondrial (paternal mtDNA)
E.g. Huntington’s Disease is an Autosomal Dominant disease, and thus every generations will be affected by it.
Down’s Syndrome: Trisomy 21
Klinefelter Syndrome: XXY
Turner Syndrome: XO
Fragile-X Syndrome: X-Linked Dominant ( FMR1)
Duchenne Muscular Dystrophy: X-Linked Recessive (DMD
gene)
Huntington’s Disease: Autosomal Dominant (HTT gene)
Tay Sachs: Autosomal Recessive (HEXA gene)
Cystic Fibrosis: Autosomal Recessive (CFTR)
Sickle Cell: Autosomal Recessive (HBB gene)
Common Genetic Disorders and Their Mutations
Royal Family Pedigree (X-linked recessive)
Autosomal Recessive Blood Disorder Some Symptoms: anemia, fever, chest pain,
increased risk of infections, especially respiratory infections, death
http://www.youtube.com/watch?v=9AHFHleYwdU
Sickle Cell
Malaria:◦ Vector-borne disease, parasites are transmitted by
mosquitoes through blood◦ Symptoms include fever, chills, flu-like illness, may
cause death◦ In 2010 an estimated 216 million cases of malaria
occurred worldwide and 655,000 people died, most (91%) in the African Region (CDC, 2010)
Sickle Cell◦ Carriers have increased resistance against malaria◦ 60% protection against overall mortality
◦ http://www.youtube.com/watch?v=1fN7rOwDyMQ&playnext=1&list=PLD371690519F378F5&feature=results_main
Sickle Cell and Malaria
Sickle Cell Anemia
= Carriers of the disease= Unaffected Individuals
= Affected by the Disease