Family History

High risk of autism among siblings

It's the first question parents ask when their child is diagnosed with autism: Will his future brothers or sisters have a higher risk of developing it too?

According to the largest study of siblings in families with autism, the answer is yes. Among 664 children who had at least one older sibling with the developmental disorder, the average risk of autism was nearly 19%, dramatically higher than previous sibling-recurrence estimates that were anywhere from 3% to 10%. Kids with more than one older autistic sibling had an even higher risk of the disorder: 32%.

The results underscore the fact that genes...

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