I think my son's AS could be a mixture of many things. But I don't think it came from him having the MMR. Looking back on the way he was when he was smaller, and comparing my 1 year daughter with him, she seems to be that bit more advanced than he was at the same age.
I think the causes could be a difficult birth, my pregnancy was wonderful but I was 11 days overdue, and had to be induced. I was pushing for well over an hour before they decided I needed help. My son was delivered by ventouse (suction) and his head was very mis-shapen and he still has a "strange" shaped head. The cord was also wrapped around his neck, although he didn't need oxygen.
I also think it could be genetic, coming from my side of the family. I have a half brother that has had an awful lot of problems in his life and I'm wondering now if he could have AS. But one thing I'm learning is, to stop going over and over what could have caused it. I think I could be driven mad wondering about the cause. Unless like lisapow you are certain of the cause.
My son had good Apgar scores, but he didn't crawl until he was 12 months old and he didn't walk until he was 16 months old. His speech has always been ok. But he does seem older beyond his years, which I think is a trait of AS. I'm still learning what is and isn't AS!