From the Autism Research Institute:
Autism is a (potentially) severely handicapping disorder which begins at birth or within the first 2½ years of life. For many years autism occurred in about 5 children per 10,000 live births. However, since the early 1990's, the rate of autism has increased enormously throughout the world, so that figures as high as 60 per 10,000 are being reported. The reasons for the increase are being debated, but the most likely cause appears to be the over vaccinations of infants.
Most autistic children are perfectly normal in appearance, but spend their time engaged in puzzling and disturbing behaviors which are markedly different from those of normal children. They may stare into space for hours, throw uncontrollable tantrums, show no interest in people (including their parents) and pursue strange, repetitive activities with no apparent purpose. They have been described as living in a world of their own. Some autistic individuals are remarkably gifted in certain areas such as music or mathematics, as depicted in the film Rain Man. All need help.
What is the Cause? The causes of autism are poorly understood, although it is clear that autism is a biological brain disorder. The Autism Research Institute is investigating various possible causal factors.
What is the Outlook? In recent years there has been a marked increase in the percentage of children who have been able to attend school with normal children, and to live more or less independently in community settings. However, the majority of autistic persons remain severely handicapped in their ability to communicate and socialize with other people.