Middle Eastern cultures are tribal and heavily consanguineous.
Marriage between cousins has been part of the culture for millennia
leading to "founder" effect and a large number of
autosomal recessive diseases.
In Saudi Arabia like other Middle East
countries first cousin marriages account for 60 -70% of all
marriages, leading to uniquely common disorders which are either
rare by Western standards or are unknown. The practicing physician
must include these unusual disorders in his diagnostic considerations,
since cybernetic trees described for European countries or USA
may not be valid for the Middle East.
A review of the combined files of the
Armed Forces Hospital and the King Faisal Specialist Hospital
and Research Centre, Riyadh, over 10 years period, documented
more than 150 varieties of neurodegenerative disease among 2,000
children; 27 of which constitute more than half of these files
(Table 1). Some autosomal recessive disorders are common eg.
sickle cell anaemia and thalassaemia. Others are unique eg.
Sanjad Sakati syndrome and Al-Aqeel-Sewairi syndrome. In these
disorders the exact molecular defect is found. Therefore, prevention
is possible by either pre-implantation genetics diagnosis or
prenatal diagnosis according to the recommendation of our Islamic