Genetic referrals of Middle Eastern origin in a western city: inbreeding and disease profile.

Inbreeding or consanguineous marriage is a common traditional practice in Middle Eastern cultures. Studies from various countries and communities of this region showed that the frequencies range from 20% to greater than 70%. Inbreeding is known to have adverse effects on morbidity and mortality, in particular with respect to autosomal recessive disorders. This study examined 200 couples representing all referrals of Middle Eastern origin seen at a large Clinical Genetics Unit in Montreal. They were compared with a similar sized group of different cultural backgrounds from among the same referrals. The rate of intercultural marriages and inbreeding was found to be 24% and 23.5% respectively in the Middle Eastern group, while they were 22.5% and 5% in the comparison group. Excluding the referrals for consanguinity only, the rate of inbreeding among the study group was 16.4%. Within the Middle Eastern group, autosomal recessive disorders were more than twice as common in the inbred than in the non-inbred families, the pattern of which is consistent with previous observations.