What with certain people delaying childbirth more and more (afluent anglos, some hispanics), I've been wondering if, along with the known risks of Down's Syndrome, there isn't a respectively higher risk of unseen genetic problems. Perhaps problems that don't manifest themselves as obviously as Down's. Perhaps even genetic problems that wont show up at all in the individual offspring, but which may show up in subsequent generations.
I've often wondered if perhaps this will lead to a dumbing down of the population in general. This genetic damage is passed down by smarter, more affluent people, and causes fertility, survivability, and breedability problems. Whereas the "dumber" folks who breed early, have healthy offspring with no breeding problems.
Just idle speculation, and a note, I am NOT saying ALL older parents are smart, or that ALL young parents are dumb, of course.
Maybe you might be interested in some of these links on older fathers and risks of problems for offspring????????
http://press.psprings.co.uk/jech/october/851_ch45179.pdf Many problems have been associated with having children,later not earlier. 35 for both men and women is beginning to be later. See James F.Crow
http://www.pnas.org/cgi/content/full/94/16/8380 This information about risks of older parenting is not new,but it has been hidden for some reason.
http://humrep.oxfordjournals.org/cgi/reprint/13/9/2371.pdf
There is research to look at if one has an open mind and if one realizes that autism is not one thing, or one gene, or if the genes exists mildly already in a person one can have an more autistic child at 20. So, maybe the older a man the more mutations in his sperm and the less ability to kill off the mutated sperm.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T6K-4B52S86-P&_coverDate=12%2F31%2F2003&_alid=481273960&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5033&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=113136870c266c7b8005023fc27a06d8 Yes, young engineer types will tend to have more autistic children, but maybe also 36 +++ men who are lawyers, and not scientists. This all does not mean that there aren't plenty of very non-autistic people with fathers who were in theirlate 30s, 40s, 50s, 60s ++. This information is not meant to blame older fathers, but knowledge is power. It takes a lot of time and will to begin to sort this issue out.