There is not just one cause of ASD. There are many different factors that have been identified that may make a child more likely to have ASD, including environmental, biologic, and genetic factors.
Although we know little about specific causes, the available evidence suggests that the following may put children at greater risk for developing ASD:
- Having a sibling with ASD
- Having certain genetic or chromosomal conditions, such as fragile X syndrome or tuberous sclerosis
- Experiencing complications at birth
- Being born to older parents