Consanguinity and major genetic disorders in Saudi children: a community-based cross sectionalstudy

BACKGROUND AND OBJECTIVES: There is a high rate of consanguinity in Saudi Arabia; how ever, informationon its relationship with genetic disorders is limited. The obj ective of thi s cross-sectional study was to explore therole of consanguinity in genetic disord ers.SUBJECTS AND METHODS: The study sample was determined by a mul tistage probability random samplingprocedure. Consanguinity status was obta ined during household visits. Primary care physicians perform ed ahistory and physical exami nation of all chi ldren and adolescents younger than 19 years, and all cases of geneticdiseases were record ed. The chi-square test was used to compare proportions.RESULTS: During the two-year study period (2004-2005), 11 554 of 11 874 (97%) moth ers answered the questionon consanguinity, and 6470 of 11 554 (56%) were consanguineous. There was no signifi cant associ ationbetween first-cousin consanguinity and Down syndrome (P= .55). Simil arly, there was no significant associ ationwith either sickle cell disease (P= .97) or glucose-6-phosph ate dehydrogenase defi ciency (P= .67) for first-cousinconsanguinity. A bord erline statistical significance was found for major congenital malformation s (P= .05).However, the most signifi cant association with first-cousin consanguinity was congenital heart disease (CHD)(P= .01). Finall y, no signifi cant associa tion was found for type 1 diabetes mellitus (P= .92) . For all types of consanguinity,simil ar trends of assoc iation were found , with a definite statisticall y signifi cant association onl y withCHD (P=.003 ).CONCLUSION: The data suggest a significant role of parental consanguinity in CHD. However, a relationshipbetween consanguinity and other genetic diseases could not be established. The effect of consanguinity on geneticdiseases is not uniform and thi s should be taken into consideration in genetic counseling.