"Autism" is such a broad term that it's probably wise to not ascribe any one cause to all of it. There are cases where you can argue about whether this is autism or not. And there are cases where there is no doubt. You can be a slightly odd well-functioning member of society, or you can be so crippled you require special care 24/7.
ETA: I feel pretty bad at the moment, so I won't participate unless there's something truly egregious.