Hello Alice,
I have no experience with genetic diseases. My son's best friend has cystic Fibrosis as well as his sister. I have tried to approach them but their father is a surgeon and they have a very strong mindset, and so far, they have been fairly well.
On the serious diseases DVDs, Gary deals with a young man who has Cystic Fibrosis, he treats the symptoms as they are and includes some challenges to the beliefs, "Even though they say I have a genetic disease and the world believes that there is nothing I can do, I choose to be open to the possibility that this is a belief"..." I choose to believe that I don't have to go down that path..."
Tap on the feelings about inheriting this disease.Work at keeping an open mind.
Bruce Lipton talks about our perception makes our physical reality (biology) (The biology of beliefs).
Best wishes,