The risk that an infant with an older sibling with autism also will develop the disorder, previously estimated at between 3 and 10 percent, is substantially higher at approximately 19 percent, a large, international, multi-site study led by researchers at the UC Davis MIND Institute has found. While the study found a combined estimated risk for all participants of nearly19 percent, it found an even more elevated risk of recurrence of over 26 percent for male infants, and over 32 percent for infants with more than one older sibling with autism.
The study is the largest prospective investigation of autism spectrum disorder and sibling recurrence to date. It is published online today and will appear in print in the September issue of the journal Pediatrics.
The study has important implications both for genetic counseling for parents and for referral to early intervention for the infant siblings of children with autism if concerns arise about their development, said Sally Ozonoff, professor of psychiatry and behavioral sciences at the MIND Institute and the study's lead author.
"This is the largest study of the siblings of children with autism ever conducted," Ozonoff said. "There is no previous study that identified a risk of recurrence that is this high," she said.
Autism is a complex disorder that affects a child's ability to think, communicate, interact socially and learn. The U.S. Centers for Disease Control and Prevention places the incidence of autism at 1 in 110 children born today.
The participants in the study were enrolled in separate studies that are part of the Baby Siblings Research Consortium, an international network supported by Autism Speaks that pools data from individually funded research sites to facilitate the study of infants at high risk of developing autism because they have an older sibling with the condition. There is strong evidence that genetic factors play a critical role in vulner
|Contact: Phyllis Brown|
University of California - Davis Health System