It’s not easy being the brother or sister of an autistic child. “Typical” siblings sometimes feel embarrassed by or responsible for their autistic sib, or may feel jealous of all the attention he gets. Now researchers have found that the siblings of autistic children are affected in another way: up to 20% of these brothers and sisters may have subtler autism-related symptoms of their own. (More on Time.com: Autistic Kids: The Sibling Problem).
The new study involved nearly 3,000 children in 1,235 families with at least one autistic child. All the families had participated in a larger online registry of 35,000 autism-affected families called the Interactive Autism Network.
Of the families included in the current study, 10.9% had more than one child diagnosed with an autism spectrum disorder (ASD). This is consistent with previous research showing that siblings of autistic children are at much higher risk of having an ASD than other children — 22 times higher than children without affected siblings.
But what surprised the researchers was that an additional 20% of the siblings of autistic children showed language delays, and half of these kids had subtle speech problems that are characteristic of autism, such as reversing pronouns or using invented words.