September 9, 1999
Genetics and Heredity
Question from the state of Washington, USA:
I am a 35 year old insulin dependent diabetic. I got it at an early age. My dad’s mom had it and he got it at age 21. My wife is having a baby in several months. Is there a test that can be run to find our if my baby carries the genes or cells that can cause diabetes?
Nowadays the answer to your questions would depend, to some extent, on knowing exactly what kind of insulin dependant diabetes was in your family. Assuming though that it is the commonest form in North America which is Type 1A (autoimmune) diabetes, there are several ideas to consider. In the first place the overall lifetime risk of the baby developing this form of diabetes is quite low, that is, around 5-7%. You might though discuss with your wife’s obstetrician the possibility of amniocentesis for the purpose of HLA typing. This might give you some idea as to whether the baby would be genetically predisposed to diabetes or indeed might be very unlikely to develop the condition.
However being genetically susceptible does not predict the likelihood of environmental triggers for clinical diabetes. My guess is the obstetrician would rather strongly discourage any attempt at antenatal HLA typing.
You might however want to consider enrolling child later in a research study such as the DPT-1 which is designed to test the value of very small doses of insulin in preventing clinical diabetes in children with an affected first degree relative and a positive antibody test. The number to call to learn more about the DPT-1 is 1-800-425-8361.