How very sad, it's an horribly cruel disease.
My father in law had early onset and my husband worries terribly that it's his fate too which isn't helped by my mother in law frequently mentioning that his grandfather also had it.
Slightly on subject, it annoys me so much that there are people who seem to think it's acceptable to make jokes about Alzheimer's. It's a disease that's just as horrendous as cancer yet no one jokes about that.