Mike, I'm sorry.
I have MS, Dad had ALS, my grandmother had alzheimers, another aunt has MS. My neuro believes bothALS and MS are auto immune and caused by a weird protein in our brains but not necessarily a gene if that makes sense. Had my dad not passed, she wanted to study my family because she thought something was going on with us.
I'm 35. Knowing what I know, I'm glad I have only 1 child. I also want to earn as much as I can for as long as I can and get as much life insurance as I can (difficult for those with MS). I would die if I passed MS or ALS on to my child. Knowing we might have this quirk I know I might possibly have to take care of my brother at some point (his wife is a piece of crap). I don't live my life differently per se but I travel a lot with my family, I don't live in the biggest house. I want to focus on making memories for her because I know my time could very well end like my fathers did. I think they deserve to know, but, only when they are at the age when they can process it. Typically, after college, before they meet "the one" and waaaay before kids. Not that it happens like that anymore but you get the idea.