We already know what happens to the brain in autism - Dr. Manuel Cassanova

Autism is a developmental disorder caused by heterochronic division of germinal cells. Evidence for this fact is based on the presence of heterotopias and cortical dysplasias in the brains of autistic individuals. This mechanism appears to hold true for both idiopathic and syndromic autism. Dr. Casanova’s specific area of focus recently has been the identification of risk factors that can propitiate germinal cell divisions in genetically susceptible individuals with autism. At present, one of the more intriguing factors appears to be the use of prenatal ultrasound. What is most intriguing is the possibility of a triple hit in autism that could explain the observed clinical heterogeneity of autism spectrum disorders. In this regard, variations in the severity of an exogenous factor(s), timing during brain development, and genetic susceptibility of the individual may account for clinical heterogeneity.