There is strong evidence that the cause of autism has a genetic component. A pair of identical twins is 60-92% likely to both have autism. The interaction of at least ten genes contributes to autism. There are countless numbers of genes linked to autism. Though it has been found that overall there is no single genetic cause of autism but rather a number of rare mutations. Autism is an epidemic and a genetic epidemic does not exist.

Other causal factors that have been recognized are conditions of the pregnancy including the mother’s age and susceptibility to infections that are associated with autism. Environmental factors exposed during pregnancy, such as increased testosterone exposure, medications, and toxins that have a significant relationship with the degree of autism. In summary autism is a phenomenon that results from more than one cause, with different manifestations in different individuals that share common symptoms.