to a previous study about genetic links - but I couldn't find it. It showed a connection between AS, tourettes, OCD, and I'm not sure what else.
From what I've heard - it seems that the genetic link is not direct so much as it could be a matter of a tendency to not process toxins like mercury as effectively as others. Glutatheione levels, immune systems and all that. At least that is one theory.
It is interesting to see more being figured out - what with family connections and all.
"A girl with a deletion of SHANK 3 in the third family suffered from autism while her brother, who had an additional copy of the gene, had a mild form of autism called Asperger syndrome."
Here is a different genetic study from Costa Rica:
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1084355