October 3, 2006
Diagnosis and Symptoms, Genetics and Heredity
Question from Quality, Kentucky, USA:
My 18 year old son was diagnosed with diabetes two years ago. His blood sugar at diagnosis was 420 mg/dl [23.3 mmol/L]. The diabetes was a surprise because he does not have any ancestors, on either side, with diabetes. He was first diagnosed as a type 1, but the diagnosis was later changed to idiopathic glucose intolerance. My son was dismissed from the children's diabetic clinic because he turned 18 this year. His type of diabetes has always been unclear. He is able to maintain decent glucose levels with diet and exercise. He has been a cross country runner for eight years, so exercise has not been a problem. He recently saw blood sugar levels reach 380 mg/dl [21.1 mmol/L] when his family doctor gave him steroids for poison ivy, but the sugar levels are much better now. I worry about how long his good control will last and the type of diabetes he has. Last week, I was diagnosed with pernicious anemia. I tested positive for the antibodies. I am in my 40s. I was told there is a link between some types of diabetes and pernicious anemia. Does a parent with pernicious anemia make a child more likely to have a certain type of diabetes? I also would like to know if idiopathic glucose intolerance gets worse with time?
Anyone with pernicious anemia, a type of autoimmune disorder, is more likely to have type 1 than type 2 since type 1 is also autoimmune. Exactly what type of diabetes your son has is something to discus with his diabetes team. There are specific antibody tests, islet cell and GAD-65, for instance, that could help figure this out, but they are not perfect tests. And, 18 years is a difficult time to try to figure this out. Checking for other autoimmunity issues such as celiac and thyroid disorders could also help in classification. There are also specific genetic tests that could be run for different types of type 2 (i.e., MODY). If your son is not working with a diabetes team, this should be a priority to help figure out how he should be eating, monitoring, when his diabetes changes and what type of therapy should be considered. This is not something that should be handled by most family or general physicians, in my opinion.