Deciphering A Mystery: New Research Provides Clues To The Genetic, Neurological, And Molecular Basis Of Autism

In new research, scientists have found that a specific gene contributes to autism and that autistic people have fewer receptors for the brain messenger acetylcholine, as well as more tightly packed columns of neurons in the cerebral cortex. Another study found that autistic children were less able to discriminate similar sounds than were other children.
http://www.sciencedaily.com/releases/2004/10/041030131949.htm