[oortoo]

I agree. Of course genes are involved... but that doesn't make it Mendelian. Autism would be caused by a combination of genetic and environmental factors.

The fact exists that there is no singular autism gene. And there could never be a genetic test for autism. It could predict the likelihood, but it wouldn't be pass/fail. Because there are many autism-related genes but no single gene trigger like a light switch. And you could still have all of those genes turned on and not have autism due to environmental factors.