The email itself is somewhat confusing -- and the fact that it;s a friend of a friend and please forward to everyone you know -- just screams urban legend.
I just googled it - -The NJ Developmental Disabilitilies Council explains it pretty welll, though it appears it's old news.
http://www.njddc.org/fam13-1-2-a.htm
The National Downs Syndrome Society kinda goes both ways on the issue
http://capwiz.com/ndss/issues/bills/?bill=2716626