Marriages Among Cousins Increasing

A survey found that 50.5 per cent of UAE marriages were between cousins, and 26 per cent of those were
first cousins.

However, that figure represents a rise from previous studies, said Dr Ahmad Teebi, a professor of paediatrics at Weill Cornell Medical College in Qatar.

“While this trend has been declining elsewhere, we are seeing an increase in the UAE,” he told Khaleej Times in a phone interview. “However, the increase is still relatively small.”

Teebi said that the practice of cousin marriages had decreased in Jordan, Lebanon, Morocco, Mauritania and the Palestinian population in Israel.

At a conference in Doha on Wednesday, Teebi spoke of potential problems of first cousin marriages.

“In the case of first-cousin marriage, a couple’s chance of having a baby with a birth defect rises from three per cent, which is the non-cousin marriage rate, to between 4.5 and six per cent,”
said Teebi.

“In the case of second-cousin marriages, the risk increases only slightly above that of the general population.

“The frequency of a normally-rare disease can increase among populations that marry within the family,”
he added.

“This is known as founder effect and can be observed in geographically isolated areas and among populations that practice intermarriage based on circumstances, customs, beliefs or economics. We also see an increase in the number of miscarriages as a result of this practice.”

It is estimated that up to 20 per cent of marriages worldwide today are between first cousins, said Teebi. Reasons for the practice include geographical isolation, social or psychological support, convenience and tradition,
he added.

“Avoiding cousin marriage will result in a real reduction of the frequency of birth defects and genetic diseases in general,” Dr. Teebi said. “But if marriage between a close relative is unavoidable, I encourage premarital genetic counselling. This may include carrier testing and would help the couple and their doctor create a plan for prevention.”

Fast Facts

• Cousin marriage is common around the world; up to 20 per cent of couples world-wide are first cousins
• Genetic problems attributed to cousin marriage are major concerns world-wide
• In Arab countries, cousin marriages range between 20 and 70 per cent; across the Arab world, the overall average is 40 per cent
• First cousins share about 1/8 of their genes. The probability that their children inherit identical gene copies from both of them is 1/16
• Second cousins share 1/32 of their genes. The probability that their children inherit identical gene copies from both of them is 1/64
• Any relationship beyond second cousin is considered similar to random marriages in terms of gene sharing (except for marriages within an isolated tribe with traditional practice of cousin marriage)
• The reasons for cousin marriages are many and may include social, cultural, economical, psychological and religious
• Any person could carry three to five deleterious recessive genes that may cause disease if the two copies of the mutated gene are there. This is more likely to occur as a result of cousin marriage because of the similarity of the genes carried
by the couple
• First cousin couples are expected to produce a .5 to 1 per cent increase in the frequency of birth defects and genetic problems. In other words, any couple has a three per cent chance to have a baby born with a birth defect or genetic disease, while first cousin couples have 4.5 to 6 per cent risk
• Avoidance of first cousin marriage will decrease the frequency of birth defects and genetic problems
• Genetic counseling and other means for prevention of birth defects is essential for those entering cousin marriage

Public education is essential to increase awareness of problems associated with cousin marriages and ways to avoid them.

martin@khaleejtimes.com