The mystery of autism

US News and World Report has an article about the mystery of Autism:

eurologists and parents desperately want to unlock the mystery of autism, a brain disorder that strikes as many as 5 of every 1,000 children and causes difficulty in communication, socialization, and learning. Numerous theories have been offered to explain the baffling disease, including genetic causes, environmental factors, and an attack on the brain by an immune system gone haywire. While there is evidence of a hereditary link, the disease is increasing quickly enough to suggest other factors are also involved, so scientists are busy studying those possibilities. (The scientific studies looking at vaccination as a potential cause have largely discounted this theory.)