June 26, 2003
Genetics and Heredity, Research: Cure
Question from San Diego, California, USA:
I am six months pregnant with my first child, and even though my husband himself does not have diabetes, there is a strong family history of type 1. Could he be a carrier? How likely is it that our child will inherit type 1 diabetes given his family history? Are there any tests that can be done either before birth or after to test the likelihood of our child developing type 1 diabetes? Should we consider banking umbilical cord blood for future use if the baby does develop type 1 diabetes?
Type 1A (autoimmune) diabetes has both a genetic and a so far undefined environmental component. If you or your husband had this form of diabetes the chances of it occurring in any offspring would be of the order of only 5%. With a diabetes history only in second degree relatives, the risk is significantly less, albeit still somewhat more than for the population as a whole.
HLA antigen typing after birth somewhat increases the accuracy of prediction, but at the present, there is no known way of preventing autoimmune diabetes in those who are known to be vulnerable.The issue of banking cord blood has arisen a number of times recently, but the opinion of those who are experts in the stem cell field are still that the expense is not justified especially as techniques have now been developed for deriving islet producing cells from primitive bone marrow.