A couple of noteworthy authors/speakers on the topic are Dr. Gabor Maté and Dr. Bruce Lipton.
Dr. Maté is a mainstream physician who was born into a Jewish family in Hungary just as the Nazis were occupying. Through his career he has closely studied the role of early life trauma in long-term behavioural and physiological illness. Here's an article he wrote about autism . He's written a bunch of books about links between trauma and long-term health outcomes .
Dr. Lipton was a pioneering stem cell biologist in the 70s and 80s, who became particularly interested in the role of experience/belief/trauma on behavioural and physiological outcomes. In his book, The Biology of Belief , he covers the statistical link between early life trauma and autism, and proposes a biological basis for it.
Lipton is a controversial figure who is easily ridiculed by mainstream medicine devotees as he gets handwavy about quantum physics and has become involved with the new age spirituality movement. But, having applied his ideas very successfully in my own life over the past few years, I can attest that what he's right about is more important than what he might be wrong about.