Let's not be confused about this...
There does not yet exists a definitive clinical link between genetic heritage and AS/Autistic syndrome - but, and this is a *big* but - there is a definite increase in the probability that a child will exhibit AS/Autistic traits if they have family members who also exhibit similar traits.
So, while the clinical jury remains out, the fact is that it probably "runs in the family". And while there's no requirement that you have a family history (genes can be recessive in both parents and yet yield a dominant trait in a child), if you've got a parent or close family member with an AS disorder then you're far more likely to have one of your own.
Bottom line - if you have AS/Autistic Spectrum problems, and you have a family member who exhibits similar symptoms, then you're got a critter that's quacking that is probably a duck, and if it looks like a duck and quacks like a duck, then it's almost certainly a duck
Nick