What are the different causes of autism?

Answers will vary. Contrary to what some theorists say or some of the public believe, scientific evidence shows that there is no connection between the development of autism and use of vaccines or deficiencies in child rearing. Various lines of evidence suggest a key role for biological factors in autism. Possible prenatal factors include exposure to lead, alcohol, mercury, misoprostol, and maternal rubella. Very low birth weight and advanced maternal age may heighten the risk of autism. Biological factors focus on neurological involvement. Many children with autism have abnormal brain wave patterns or seizures.