Question from Houston, Texas, USA:

My 15 year old daughter had some abnormal test results and was referred to a pediatric endocrinologist last summer. The first appointment available was in October, so we have just now gone for the visit. She had been extremely tired and her pediatrician ran some tests. Her A1c was 5.9. and her insulin levels were high, although her GTT (glucose tolerance test) was normal. At home, she has had some blood sugars in the 150s mg/dl [8.3 to 8.8 mmol/L] about three hours after she had eaten. Her fasting blood glucose readings are usually in the high 90s to 107 mg/dl [5.5 to 5.9 mmol/L]. After a steroid shot for an allergic reaction, the next morning, her blood sugar was 132 mg/dl [7.3 mmol/L]. She is tall, thin and very active. Her A1c in October was 5.2.

I have type 2 and Graves disease. Of the nine children in my father’s generation, six have diabetes. Three are on insulin and none are obese. Some are thin. The three who are not on insulin take oral medications. We have both type 1 and type 2 in our family. The doctor remarked that it was unusual that I am thin and have type 2 and asked if I really had type 2. (My diabetes is very mild and is diet and exercise controlled, at this point.) She also thought it was odd that my daughter had high insulin levels and is thin. She said something about this not being typical and something about a genetic trait involving a receptor that regulates insulin. I may not have understood her correctly. Can you shed any light on this? The doctor is going to repeat the tests in six months and, in the meantime, see if there is a test available for this gene, or something like that. Could our family have some weird kind of diabetes that is a combination of type 1 and type 2? Could it affect some of us worse than others?