Autism spectrum disorder affects children of all races and nationalities, but certain factors increase a child's risk. They include:

  • Your child's sex. Boys are about four times more likely to develop ASD than girls are.
  • Family history. Families who have one child with ASD have an increased risk of having another child with the disorder. It's also not uncommon for parents or relatives of a child with ASD to have minor problems with social or communication skills themselves or to engage in certain behaviors typical of ASD.
  • Other disorders. Children with certain medical conditions have a higher than normal risk of ASD or ASD-like symptoms. Examples of these conditions include fragile X syndrome, an inherited disorder that causes intellectual problems; tuberous sclerosis, a condition in which benign tumors develop in the brain; the neurological disorder Tourette syndrome; and Rett syndrome, a genetic condition occurring almost exclusively in girls, which causes slowing of head growth, intellectual disability and loss of purposeful hand use.
  • Extremely preterm babies. Babies born before 26 weeks of pregnancy may have a greater risk of ASD.
  • Parents' ages. There may also be a connection between children born to older parents and ASD, but more research is necessary to establish this link.
June 03, 2014