Question:What is the risk that a child will develop diabetes if one or both parents are diabetic?
Answer: The key factor in figuring out the familial risk of diabetes is what we call first-degree relatives. The number of first degree relatives -- that is to say parents, siblings or children -- who have the disease. If you have one first-degree relative who has type 1 diabetes, you're risk is on the order of 10 to 15 times higher of getting that disease than if you don't. One the other hand, that 10 or 15 times increased risk still means that it's a low probability you'll actually get the disease. In other words, it might be 1 in 200 of getting type 1 diabetes if you're walking down the street, living in America. It might be 1 in 10 or 1 in 20 if you have a parent, or a sibling or a child who has the disease. But that still means it's unlikely because those other factors -- environment and behavior and bad luck -- play a big role.
In type 2 diabetes, if you have a sibling or a parent who has the disease, you're risk is as high as 1 in 3. And if you have two siblings or two parents who have the disease, it's higher still. But even in type 2 diabetes, where the absolute risk is higher, there's still many non-genetic factors and our behavior can change the likelihood of getting the disease.