InThe Medical Genetic Unit of King Abdulaziz University in Jeddah was established by the author in February 2005. It contains the first genetic clinics in the Western region of the Kingdom of Saudi Arabia. Jeddah, the commercial capital and the second largest city of Saudi Arabia, has a population of over 3.5 million people with a 2.06% growth rate and the median age of 21.4 years. Referrals are received from Jeddah and surrounding cities and towns in the Western Region including among others Makkah, Taif, and Al-Baha. The objectives of this prospective study were to study the pattern of genetic disorders over a 4 year period, elucidate their inheritance patterns, set up a platform for a genetic database in the region and identify the relevant risk factors for genetic conditions in our population, especially those which are potentially preventable. Nine hundred and four patients with genetic disease have been assessed. Each patient received a full genetic assessment including s dysmorphological examination. Imaging and laboratory testing (including genetic testing) were done as appropriate. The most likely inheritance pattern was based on the diagnosis and analysis of family pedigree. The most common form of genetic disease was autosomal recessive followed by chromosomal disorders and then autosomal dominant disorders. Unlike some other reports from Saudi Arabia, consanguinity was more likely to be present in individuals with autosomal recessive disorders than with any other form of genetic disease including isolated congenital malformations. Recommendations to decrease the burden of genetic disease in this region including our experience with the current Premarital Screening in our student population are discussed.

Population of Saudi Arabia is a mixture of ethnic groupsSpecific genetics and cultural factors Consanguinity rates: 2560%-Diminished awareness of the importance of genetic counseling in preventing malformations

Study the pattern of genetic disorders at the western region of KSA over a 24 month periodElucidate the inheritance patterns for these genetic disordersDetermine the relevant risk factors for genetic conditions in this population- especially those that are potentially preventableProvide recommendations for reduction of genetic disorders- role of genetic counseling and feasibility of antenatal diagnosis

Cosmopolitan cityPopulation >3 millionCommercial capital of Saudi ArabiaWestern coast of the Red SeaMulticultural societyHeterogeneous population

Comparison of advanced maternal age between individuals with trisomies vs. all other groups :Trisomies: 60% of mothers were of AMA.Others: 27.6% of mothers were of AMA.

Unlike some other reports from Saudi Arabia, consanguinity was more likely to be present in individuals with autosomal recessive disorders (56.25% ) than with any other form of genetic disease ( 22.9%)including isolated congenital malformationsIn 38.8% of infants with congenital malformations the parents were consanguineous.

Estimated recurrence risk of genetic disorders is > 1% in almost all cases and more than half RR ≥ 25%.Overall 32.61% of all cases had a RR >1% AND Antenatal diagnosis was possible and feasibleThe need for genetic counseling is underscored by the fact that 55.4% of mothers were <36 years and likely to have further children.Factors amenable to premarital and preconception counseling and more common in the region are consanguinity and advanced maternal age.A condensed public education program in addition to education of all health care providers who can play an essential role will be highly cost effective in reducing the burden in genetic disorders in the KSA.

BACKGROUND

JEDDAH

ABSTRACT

Distribution of Underlying Etiology

OBJECTIVES

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0

10

20

30

40

50

60

70

80Types of Chromosomal Disorders

DS (N

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DS (t

ranslo

catio

n)Tri

somy 1

8Tri

somy 1

3De

letion

Microd

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n

other

05

101520253035

Most common Autosomal Dominant Disorders

Noon

an sy

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e

Achon

dropla

siaEh

ler-da

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Marfan

Synd

rome

CDL

Coste

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Rubin

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other

233329

141111

DMD Fragile X

X-linked hydrocephalusAicardi syndrome

Simpsom-Golabi-Behmel syndromeLesch Nyhan syndrome

Retinitis pigmentosa (x-linked type)orotic aciduria

X-linked Thalassemia with mental retardationRett syndrome

Oro-facial digital syndrome (OFD) type II

Diagnosis No.

X-linkd Disorders

Cerebellar Dygenesis

CDP

Cockayne syndrome

Collodion baby

Congenital Adrenal hyperplasia

Congenital myopathy

Congenital nephrotic syndrome

Sonada-Kaouna

Dubowitz syndrome

JEB

Ehlers-Danlos syndrome,

type VI

Familial hypermagnesemia

GSD type III

Hurler syndrome

Jarcho-levin syndrome

Joubert syndrome

Neimann-Pick Disease

Neurodegenerative disease

O. I. type 3

O. I.

PKU

Retinitis pigmentosa

RCDP type 1

Russel Silver syndrome

Sanjad-Sakati syndrome

SCA

Seckel syndrome

SMA

Spinocerebellar Ataxia

Tay-Sach Disease

Walker-Warburg syndrome

Wolcott-Rallison syndrome

Xeroderma pigmentosa

The Most Common Autosomal Recessive Disorders

CONSANGUINITY

CONCLUSIONS:

Genetic Disorders: Experience in Saudi Arabia Jumana Y. Al-Aama, Alaa Y.Edrees

Princess Al Jawhara Center of Excellence in the Research of Hereditary Disorders,King Abdul-Aziz University, Jeddah, Saudi Arabia