Type 1 diabetes in various sources includes: A Family history of Type 1 diabetes - but a family history of Type 2 diabetes is not an extra risk Personal history of autoimmune diseases Risk factors for Type 1 diabetes are factors that do not seem to be a direct cause of the disease, but seem to be associated in some way. Having a risk factor for Type 1 diabetes makes the chances of getting a condition higher but does not always lead to Type 1 diabetes. Also, the absence of any risk factors or having a protective factor does not necessarily guard you against getting Type 1 diabetes. Babies harmed by mother's weighty issues Blood protein concentration may determine heart disease risk Children increasingly face adult diseases Diabetes: the simple facts Diabetic children need to use continuous glucose monitoring to achieve good control of their condition Eating disorders can greatly increase the risk of complications in people with type 1 diabetes International research aims to determine if cow’s milk increases risk of type 1 diabetes Long-term offspring health may be affected by mother’s diet during pregnancy New diagnostic technique for pre-diabetes Poor glucose control in teenage diabetics may compromise their bone formation Pregnant diabetics at higher risk for birth defects

Firebrand do any of the adults you know with DT1 have these risk factors http://cat.inist.fr/?aModele=afficheN&cpsidt=16480235 There are some factors in studies that are not commonly discussed. I don'tknow why this posted as an answer it is not an answer but a comment

Tantric is right, however they are looking at the aspect of not all Type 1's are due to genetic heredity of the disease. I have had Type 1 diabetes since the age of 12 and taken 4-6 shots a day since then. I have had a very hard time controlling and maintaining the disease. I have quite a few of the disabling conditions from having the disease for so long. I have had the opportunity to work with world renowned Endocrinologists and still have complications. I monitor carefully, but still fall in the "brittle" diabetic category. Some of the side effect diseases include: Chronic Fatigue syndrome Fibromyalgia Neuropathy Retinal detachment Liver and Kidney failure Of which I have all. I also have a daughter who was born Hyperinsulinemic. This means she must take medication to slow the release of insulin from her pancreas, and will end up diabetic. That does not mean there are not new drugs or treatments that will make the Type 1 diabetic's life easier. I go to a diabetes treatment class, and they are in hopes of in the next 20 years finding a cure. I hope this is true, it will make many lives easier.