Many causes of Autism have been proposed, but understanding the theory of causation of Autism and Autism Spectrum Disorder is incomplete. Research indicates that genetic factors predominate. The heritability of Autism is, however, quite complex and it is still unclear which gene or multitude of genes are responsible. Eventhough the exact cause of Autism is not known, research has pointed to several other possible factors such as metabolic and neurological factors, certain types of infections and problems occuring at birth. In some children, environmental factors may play a role. Studies of people with Autism also showed some abnormalities in the brain development and in several regions of the brain.
There is no direct cause for Autism, this disorder is multifactorial and until now no research established a clear and reliable causation of Autism.