Few Risks Seen To the Children Of 1st Cousins

In 2002 the New York Times had an article about children born to cousin couples:

Dr. Motulsky said medical geneticists had known for a long time that there was little or no harm in cousins marrying and having children. ''Somehow, this hasn't become general knowledge,'' even among doctors, he said.

Twenty-four states have laws forbidding first cousins from marrying, and seven states have limits like requiring genetic counseling. But no countries in Europe have such prohibitions, and in parts of the Middle East, Africa and Asia, marriages between cousins are considered preferable.

''In some parts of the world,'' the report says, ''20 to 60 percent of all marriages are between close biological relatives.''

Dr. Motulsky said many immigrants from cultures where cousin marriages are common expect to continue the tradition in the United States, and doctors and genetic counselors should respect their wishes.

Laws against cousin marriage should be abolished, he said. Even though longstanding ones reflect a view that such marriages are ''really bad,'' he said, ''the data show it isn't that bad.''

Dr. Motulsky said researchers did not know why marriage between cousins was viewed with such distaste in the United States. He said some of the revulsion might have stemmed from the eugenics movement, which intended to improve the human race by deciding who should be allowed to breed. The movement flourished in this country early in the 20th century.

It is not known how many cousins marry or live together. Estimates of marriages between related people, which include first cousins and more distant ones, range from less than 0.1 percent of the general population to 1.5 percent. In the past, small studies have found much higher rates in some areas. A survey in 1942 found 18.7 percent in a small town in Kentucky and a 1980 study found 33 percent in a Mennonite community in Kansas.

The report made a point of saying that the term ''incest'' should not be applied to cousins but only to sexual relations between siblings or between parents and children. Babies who result from those unions are thought to be at significantly higher risk of genetic problems, the report said, but there is not enough data to be sure.