Siblings of children with autism more likely to have mild traits of ASD
by Beth
Our friends at the Autism Society of America have posted an article on their web site about a recent study led by researchers at Washington University School of Medicine in St. Louis. The study found mild traits (not strong enough to get an ASD diagnosis) present in the siblings of children with autism at significantly higher rates than seen in the general population. From the ASA article:
“Mild symptoms, called quantitative traits, may be confounding studies that compare children with autism to their siblings,” says first author John N. Constantino, M.D. “Researchers presume one child is affected, and the other is not, but our findings suggest that although one child may have autism while the other does not, it’s very possible both children are affected to some degree by genes that contribute to autism.”
The study It also found that while many female siblings had subtle traits, few were diagnosed with ASD.
Boys are thought to be affected four times more often than girls. But when the researchers used standardized methods to account for the presence of quantitative traits, the rate looked more like three affected boys for every two affected girls.
“The gender difference may not be as pronounced as we once thought it was,” Constantino says. “If we rely only on a professional diagnosis of autism to determine who is affected, then boys vastly outnumber girls. But it may be that many girls are being missed.”
More information on the study is available now from a Washington University press release, and the findings will be published in the November issue of the American Journal of Psychiatry.