Genetics researchers at The Children’s Hospital of Philadelphia have found 25 “high impact” gene variants that occur in some patients with autism. Although rare individually, each genetic variant has a strong effect in raising a person’s autism risk. These findings could be incorporated into clinical tests for evaluating children for autism spectrum disorders.
Autism spectrum disorders, often called ASDs, are a group of childhood neurodevelopmental disorders that cause impairments in verbal communication, social interaction and behavior. As many as one in 88 children in the U.S. are affected, according to the Centers for Disease Control and Prevention. Family studies show that autism disorders are strongly influenced by genetics.
Hakon Hakonarson, MD, PhD, director of the Center for Applied Genomics at Children’s Hospital led the recent study on autism spectrum disorders. He and his colleagues from the University of Utah and the biotechnology company Lineagen, Inc. identified 25 additional copy number variations — missing or duplicated stretches of DNA — that occur in some patients with autism spectrum disorders.
The researchers first analyzed DNA from 55 people from Utah families with multiple members diagnosed with autism spectrum disorders. They identified 153 copy number variations as potentially specific to autism.
They then custom-designed a DNA array with probes for those 153 copy number variants, as well as for another 185 others previously reported to be associated with autism. The variants the researchers found, Dr. Hakonarson said, occur in genes involved in neuronal development and signaling pathways. The findings reinforced similar ones found by Dr. Hakonarson and his colleagues in 2009.
“Many of these gene variants may serve as valuable predictive markers,” said Dr. Hakonarson. “If so, they may become part of a clinical test that will help evaluate whether a child has an autism spectrum disorder.”