The general understanding of genetic disease is not great. There are people who believe that there is a moral duty to dissolve a marriage if the parties are even distantly related or if there is genetic disease involved. One of the most widely publicized cases involved a biologic brother and sister who were adopted by different families as small children. They met in adulthood, married, and had three healthy children. Another person who knew of their earlier relationship tried to force them to divorce. They quite rightly refused.

Couples should understand the genetic problem they face and the likelihood that children will be affected. Once they understand their options, the parties to the marriage will have to make their own choices. Whatever a physician may advise, strong marriages will tend to survive; weak ones may not, and genetic compatibility is often only a small part of the equation.