What are the chances of a child getting diabetes if the father has insulin dependent diabetes and marries his first cousin? Are the risks greater?

The chances of a child getting diabetes when the father has type 1 is slightly more than when the mother is affected, and in a Caucasian family would be around 7%. You might however get a clearer estimate if you both were DQB typed for susceptibility genes, but even then the environmental trigger would be imponderable. There is a National trial in England called ENDIT, which is assessing the role of the vitamin nicotinamide in delaying insulin dependence in high risk infants. If the occasion arises, you might talk to your doctor about this. At any event, the treatment of type 1A or autoimmune in the young is advancing so rapidly that this small a risk would not seem to justify avoiding having a wanted child.

DOB