Researchers find genetic marker for autism

A team of Philadelphia researchers that included geneticists from the University of Pennsylvania School of Medicine and the Children’s Hospital of Philadelphia said Tuesday they have identified what they believe to be the first common genetic risk factors for autism and autism spectrum disorders.

The researchers, in two studies, detected variations along a genetic pathway that is responsible for neurological development, learning and memory " which appears to play a significant role in the genetic risk of autism.

Their findings, published online in the journal Nature on Tuesday, suggest there is a strong genetic component increasing the likelihood of an autism diagnosis, which afflicts one in 150 children in the United States.

“We studied more than 10, 000 children " of whom more than 4,500 had been diagnosed with an autism spectrum disorder " and found a common genetic variation that increases the risk of a child developing autism, along with a rarer genetic change that contributes to some cases of autism,” said Gerald Schellenberg, a professor of pathology and laboratory medicine at the University of Pennsylvania School of Medicine and co-senior author of the study report. “This work yields important clues on what goes awry during development in children with autism and will help us focus on what is the cause of autism at a molecular level.”

The researchers found a particular genetic variation, found on a cluster between CDH10 and CDH9, is commonly found in children with autism.

“Because other autism researchers have made intriguing suggestions that autism arises from abnormal connections among brain cells during early development, it is very compelling to find evidence that mutations in genes involved in brain interconnections increase a child’s risk of autism,” said study leader Dr. Hakon Hakonarson, director of the Center for Applied Genomics at The Children’s Hospital of Philadelphia.