From the Wikipedia entry:
Autism is a brain development disorder that impairs social interaction and communication, and causes restricted and repetitive behavior, all starting before a child is three years old. This set of signs distinguishes autism from milder autism spectrum disorders (ASD) such as Asperger syndrome.[2]
Autism has a strong genetic basis, although the genetics of autism are complex and it is unclear whether ASD is explained more by multigene interactions or by rare mutations.[3] In rare cases, autism is strongly associated with agents that cause birth defects.[4] Other proposed causes, such as childhood vaccines, are controversial and the vaccine hypotheses lack convincing scientific evidence.[5] Most recent reviews estimate a prevalence of one to two cases per 1,000 people for autism, and about six per 1,000 for ASD, with ASD averaging a 4.3:1 male-to-female ratio. The number of people known to have autism has increased dramatically since the 1980s, at least partly due to changes in diagnostic practice; the question of whether actual prevalence has increased is unresolved.[6]
Autism affects many parts of the brain; how this occurs is poorly understood. Parents usually notice signs in the first two years of their child’s life. Early behavioral or cognitive intervention can help children gain self-care, social, and communication skills. There is no cure.[7] Few children with autism live independently after reaching adulthood, but some become successful,[8] and an autistic culture has developed, with some seeking a cure and others believing that autism is a condition rather than a disorder.[9]
