Yeah, not a whole lot we can do, except keep our eyes open for the symptoms and get them help early.
My wife and I even talked to a Genetic Doctor prior to having kids, because I was so concerned about it. She showed us all this data about percentage of people with the disease, with and without HLAB27, etc., etc. But now I talk to a lot of people who passed it on! I just don't know. I guess you try not to let your worry effect the kids...