Diabetes Question?

[Britt]

I am doing a project on genetically linked diseases and the one I chose was diabetes. I have to explain how it is passed down through genes but i'm not sure I understand myself. My boyfriend has a little brother that has Type 1 or juvenile diabetes but neither one of his parents do. He is not overweight and has had it since he was very young, my boyfriend doesn't have diabetes either so how in the world does his brother have it? My grandmother also has Diabetes but none of her kids do. Please help me understand!
Thanks =]

[yippie]

type 1 isnt from being overwieght, thats type 2. type 1 is usually from genetics. but it can come from other. and just because one person in a family has it doesnt mean that everyone will have it. its just a luck of the draw type thing. it runs in my family but only my uncle and cousin have it that i'm aware of. i'm being tested for it.

[christmasx2]

I have Type 1, but no one in my family has it. I understand that the causes are not really known, although there is a gene that makes you predisposed to Type 1 diabetes. In other words, if you have the gene, you may or may not develop diabetes, but if you don't have the gene, you will not get Type 1 diabetes. Type 2 is very different in nature, although it shares the same symptoms as Type 1. They are really two different diseases. Those who are susceptible to Type 1 are also susceptoble to other auto-immune disorders.