We've established that autism is not a vaccine related illness. What exactly do we know about how it's caused?
Scientists are currently searching for a unifying theory of autism, and the only thing that's clear so far is that it will need to be a complex, multi-hit hypothesis.
This is a far from comprehensive review, just a few thoughts of mine. As always, the best advice is not to be found on the Internet. A licensed physician or health care professional is always better than a blog, vlog, or forum.
1. Lancet. 2009 November 7; 374(9701): 1627–1638. "Autism"
2. Front Hum Neurosci. 2010 Dec 21;4:224. "The Intense World Theory – a unifying theory of the neurobiology of autism"
3. J Neurodev Disord. 2012; 4(1): 7. "Infant siblings and the investigation of autism risk factors"
Do not support Autism speaks