Assuming you are talking about type 2, I can't give you a number, but I know that they are very high. My dad has a strong family history. He is one of 7 children and all but 3 have got it. My mom also has it as do her two sister. Those sound like pretty good odds, but as always and especially with type 2 diabetes lifestyle plays a huge role. I suspect that it may have a lot more to do with growing up with similar eating habits and lifestyle than genetics, but they obviously play a huge role as well. My parents grew up in the south on good old fashioned carbolicious southern treats, so whos to say. I just know that I want to at least try to dodge the bullet my living a healthier lifestyle.