Consanguinity and major genetic disorders in Saudi children: a community-based cross-sectional study.
OBJECTIVE
There is a high rate of consanguinity in Saudi Arabia; however, information on its relationship with genetic disorders is limited. The objective of this cross-sectional study was to explore the role of consanguinity in genetic disorders.


METHODS
The study sample was determined by a multistage probability random sampling procedure. Consanguinity status was obtained during household visits. Primary care physicians performed a history and physical examination of all children and adolescents younger than 19 years, and all cases of genetic diseases were recorded. The chi-square test was used to compare proportions.


RESULTS
During the two-year study period (2004-2005), 11 554 of 11 874 (97%) mothers answered the question on consanguinity, and 6470 of 11 554 (56%) were consanguineous. There was no significant association between first-cousin consanguinity and Down syndrome (P=.55). Similarly, there was no significant association with either sickle cell disease (P=.97) or glucose-6-phosphate dehydrogenase deficiency (P=.67) for first-cousin consanguinity. A borderline statistical significance was found for major congenital malformations (P=.05). However, the most significant association with first-cousin consanguinity was congenital heart disease (CHD) (P=.01). Finally, no significant association was found for type 1 diabetes mellitus (P=.92). For all types of consanguinity, similar trends of association were found, with a definite statistically significant association only with CHD (P=.003).


CONCLUSIONS
The data suggest a significant role of parental consanguinity in CHD. However, a relationship between consanguinity and other genetic diseases could not be established. The effect of consanguinity on genetic diseases is not uniform and this should be taken into consideration in genetic counseling.
El Mouzan
Mohammad I
MI
Department of Pediatrics, King Saud University, Riyadh, Saudi Arabia.
Al Salloum
Abdullah A
AA
Al Herbish
Abdullah S
AS
Qurachi
Mansour M
MM
Al Omar
Ahmad A
AA
D000293:Adolescent; D003241:Consanguinity; D003430:Cross-Sectional Studies; D005260:Female; D030342:Genetic Diseases, Inborn / Q000453:epidemiology*; D006330:Heart Defects, Congenital / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D008297:Male; D012307:Risk Factors; D012529:Saudi Arabia / Q000453:epidemiology