CAUSES OF AUTISM
There is no definitive explanation as to what causes autism, but research is ongoing. There is general consensus among most mainstream researchers that genetics plays a large role and may be responsible for up to 90 percent of the occurrences. Researchers have identified as many as 10 or more genes that may play a role in determining whether a child develops autism.
Scientific research also suggests that other factors may increase the likelihood of autism. Prenatal risk factors such as diabetes or the use of psychotropic drugs by a mother during pregnancy may play a role in determining whether a child develops autism. Children born to older than average parents may be at greater risk. Babies born prematurely and those who experience hypoxia during birth may face a greater risk of autism. Prenatal viral infections may be the principle non-genetic cause of autism.
Numerous studies have been conducted to explore this hypothesis. Researchers have concluded that there is no scientific evidence to support the hypothesis that vaccines or immunizations cause autism.