Kelly,
Now you've gotten me very curious. Is the mother someone you know, or a total stranger? You are much better off having the child get the gene from the Mom and not the Dad because it is very unlikely statistically that the age of onset will be less than Mom's. I really truely believe there will be a cure or treatment within the next few years so all these concerns may be invalid. What I would be more concerned about today is the health of the mother especially during the pregnancy. Has she been abusing drugs or alcohol? Is she relatively healthy? Has she been getting good prenatal care or at is the baby at risk for birth injury or or hypoxia? Those kinds of problems can mess up a child from day one. My dear friend adopted a child a several years ago and she had been told that he would probably live less that a year because of muscular dystrophy. Anyway he is now 7 and needs a wheelchair and lives day to day, but is the joy of her life and she wouldn't have missed out on these seven years for anything. I know what advice she would give you. Enjoy every moment and don't worry about tomorrow.
I think there is some problem raising a child that you think may have less potential than others. I think there is something psycological that makes parents not set goals for their future or spend as much time nuturing and teaching. I guess its important to make sure you can treat them like any other child and not give the impression that the future wasn't available for them. I have two at risk and used to wish that I could have them tested, but truely I don't know if I would treat them the same. Maybe I wouldn't make a child with the gene study as hard with schoolwork or maybe I would spoil them more. I just think it would be difficult as a parent to know about gene status. Please let us know what happens.