Autism is a complex neurobiological disorder that typically lasts throughout a person's lifetime. It is part of a group of disorders known as autism spectrum disorders (ASD). People who have autism have trouble communicating and interacting with other people. A child who has autism may seem very withdrawn may not make eye contact with people may not talk or play the way other children do or may repeat certain motions and behaviors over and over again. Researchers are investigating a number of theories including the link between heredity genetics and medical problems.