The World Health Organization (WHO) defines close-kin marriage, or consanguineous marriage, as one between individuals who are second cousins or more closely related. In the Middle East close-kin marriage is commonplace, promoted by social factors, such as preservation of wealth and tribal traditions. However, close-kin marriages are associated with a higher frequency of genetic disorders and birth defects than marriages between unrelated individuals.
Ahmad Teebi (University of Toronto, Ontario, Canada) and Hatem El-Shanti (University of Iowa, Iowa City, IA, USA) recommend basic information on genetic diseases linked to close-kin marriage, carrier-testing for genetic disorders, and genetic counselling for secondary school children in the Middle East.
They add: "Premarital and preconception testing and counselling for common disorders, preimplantation genetic diagnosis, prenatal diagnosis, and termination of pregnancy for severely affected foetuses (within the allowed limits in religion) should also be integral parts of the strategy to reduce prevalence of genetic disorders and birth defects. The application of this strategy, however, should be accompanied by careful and well-informed counselling to avoid stigmatisation." (Quote by e-mail; exact version does not appear in the published comment)
Contact: Professor Ahmad Teebi, Hospital for Sick Children and University of Toronto, Toronto, Ontario, ON M5G 1X9, Canada. T) 416-813-8366
The Lancet