What causes Aspergers and HFA?
Scientists don't know the exact causes of Aspergers or High-Functioning Autism (HFA), but research suggests that both genes and environment play important roles. In identical twins who share the exact same genetic code, if one has Aspergers, the other twin also has Aspergers in nearly 9 out of 10 cases. If one sibling has Aspergers, the other siblings have 35 times the normal risk of also developing the disorder. Researchers are starting to identify particular genes that may increase the risk for Aspergers. Still, scientists have only had some success in finding exactly which genes are involved. Most people who develop Aspergers have no reported family history of autism, suggesting that random, rare, and possibly many gene mutations are likely to affect a person's risk. Any change to normal genetic information is called a mutation. Mutations can be inherited, but some arise for no reason. Mutations can be helpful, harmful, or have no effect. Having increased geneti