According to the National Institute of Neurological Disorders and Stroke and The Tech Museum of Innovation, family and twin studies have shown strong evidence that individuals can be genetically predisposed to developing autism spectrum disorders. There is also evidence that environmental factors may contribute to the development of autism.
The Tech Museum of Innovation states that family studies indicate a link between autism and many different genes. Abnormal amounts of neurotransmitters within the brain are also linked to autism spectrum disorders, according to the National Institute of Neurological Disorders and Stroke. Brain abnormalities associated with autism begin during prenatal development.