I have two children with diabetes, a son, age 10, diagnosed at age seven and a daughter, age three diagnosed at age two. There are no other individuals with type 1 diabetes anywhere in either of our families.

I have two questions. First of all, my mother-in-law has rheumatoid arthritis. I have read that there may be a relationship between type 1 diabetes and this type of arthritis, since they are both autoimmune diseases. Could the diabetes in our children be attributed to the fact that my husband’s family has rheumatoid arthritis? Secondly, I am continually worried about my two other children. One of my non-diabetic sons had a fasting blood sugar reading of 105 mg/dl [5.8 mmol/L] this morning and has been wetting through his diapers a lot lately. Should I be worried? What are the odds of one family having three children with diabetes? Have you ever heard of anyone with more than two children with diabetes in one family?

It is possible to have familial genetic predisposition and then somewhat random as to the genes predisposing certain viral/environmental exposure and then damaging the beta cells sufficiently to produce type 1 diabetes. So, you may want to do formal islet cell and GAD65 antibody tests on the other two children and see if there is already evidence for autoimmunity in their bodies. What to do about this is less certain since most current therapy trials have been disappointing. I would ask these specific questions to your diabetes team since they know you and your family best and can give you the best specific advice. They would also be able to discover which, if any trials are in open enrollment and in which you might consider participating. The actual risks are very small, about 5% for each sibling. With two children, the risks increase slightly into approximately the 5-15% range.

SB

[Editor’s comment: See a previous question about the odds of three siblings being diagnosed with type 1 diabetes.

BH]