Are siblings at greater risk for autism spectrum disorder (ASD)?

Are siblings at greater risk for autism spectrum disorder (ASD)?

The truth is that genetics do play a role in autism. When one child is diagnosed with ASD, the next child to come along has about a 20% greater risk of developing autism than normal. When the first two children in a family have both been diagnosed with ASD, the third child has about a 32% greater risk of developing ASD.