Autism Risk Greater Among Siblings

A new study reveals that younger siblings of children with autism have a 20% greater risk of autism than their peers. The risk is even greater among younger brothers than sisters, which is not surprising considering autism spectrum conditions are more prevalent among males. I’m not a scientist but this study leads me to believe that genetics may play a prominent role in autism spectrum conditions.

Here is an excerpt from a story on USA Today about the study:

Autism was even more common in the younger brothers of autistic children, the study says. In general, about 80% of autistic kids are boys.

In this study, risk of autism in younger brothers was nearly three times greater than in younger sisters: 26% of brothers of autistic kids also had the disorder, vs. 9% of sisters. Scientists don’t know why autism is more common in boys, but they’re investigating, says Alycia Halladay, director of environmental research at Autism Speaks.

Given their higher risk, younger siblings of autistic kids should get careful screening, Halladay says. Studies show intensive behavioral therapy is most effective when begun as early as possible.

Read the entire article: Siblings of autistic children at a 20 times higher risk.

About Melissa

Melissa is the mother of two children on the autism spectrum and strives to provide information about all aspects of autism through her blog, The Autism Education Site. Follow Melissa on Twitter. Like me on Facebook.

© Melissa Hincha-Ownby and The Autism Education Site, 2008-2014.


  1. Oops! It’s not “20% greater risk” but “20 times higher risk”, which means about 20% of possibilities of having ASD (1% for general population).