Autism Spectrum Miscelleany & TBD
The genetic evidence is also confusing. A large number of genes appear to be associated with the autism spectrum, but none seem to be definitive. In some cases, it appears that genetic changes not shared with the parents are involved. Others have peculiar behavior, in that an allele inherited from father may act differently than one inherited from the mother.
Bottom line: this is not yet understood, but evidence is accumulating rapidly.
My guess is that it will turn out to be several independent conditions that are only catastrophic when to many of them occur together.
Finally, Arun has suggested, probably in jest, that the reason several commentators (himself included), object to the topic is that they might have AS. You can still take the test and find out!