Does Autism Run in Families?

Yes, autism runs in the family.

Autism does tend to run in families, and having one autistic child increases the risk of having another. Parents who have one autistic child have a 1 in 20 — or 5 percent — chance of having another child with autism. A younger sibling of a child with autism is 5 to 10 times more likely to have autism than a child in the general population,