“Researchers don’t know the primary causes of ASD, but studies suggest that a person’s genes can act together with aspects of their environment to affect development in ways that lead to ASD. Some factors that are associated with an increased likelihood of developing ASD include:

• Having a sibling with ASD
• Having older parents
• Having certain genetic conditions (such as Down syndrome or Fragile X syndrome)
• Having a very low birth weight

Caregivers and teachers are often the first to recognize ASD symptoms in older children and adolescents who attend school. The school’s special education team may perform an initial evaluation and then recommend that a child undergo additional evaluation with their primary health care provider or a health care provider who specialize in ASD.

A child’s caregivers may talk with these health care providers about their child’s social difficulties, including problems with subtle communication. For example, some children may have problems understanding tone of voice, facial expressions, or body language. Older children and adolescents may have trouble understanding figures of speech, humor, or sarcasm. They also may have trouble forming friendships with peers.”