A child with autism spectrum disorder may have problems in three different areas -- socializing, communicating, and behavior.
Each child with an autism spectrum disorder will have his or her own individual pattern of behavior: Sometimes, a child's development is delayed from birth; other children develop normally before suddenly losing social or language skills. In some children, a loss of language is the impairment; in others, unusual behaviors (like spending hours lining up toys) predominate.
Parents are usually the first to notice something is wrong. Unfortunately, there is often a significant delay in parents bringing their concerns to the doctor and in doctors referring a child to a specialist. Parents should trust their instincts if they feel their child is not developing normally.