A specific gene mutation appears to be tied to the severity of social deficits in kids with autism spectrum disorder (ASD), according to a new pilot study conducted by the Children’s National Health System in Washington, D.C.

The findings, published in the journal Autism Research, may be the first step toward identifying a novel biomarker to help guide interventions for children with autism.

As many as 1 in 40 children are affected by ASD. Early social symptoms of the disorder may include not making eye contact, not responding to one’s name when called, an inability to follow a conversation of more than one speaker or incessantly repeating certain words or phrases.

These symptoms often appear by the time a child turns 3.

The developmental disorder is believed to be linked, in part, to disrupted circuitry within the amygdala, a brain structure integral for processing social-emotional information.

In the new study, the researchers found that a particular gene, known as PAC1R, is expressed during key periods of brain development when the amygdala — an almond-shaped cluster of neurons — develops and matures.

A properly functioning amygdala, along with brain structures like the prefrontal cortex and cerebellum, is crucial to the development of a child’s social-emotional processing.

“Our study suggests that an individual with autism who is carrying a mutation in PAC1R may have a greater chance of more severe social problems and disrupted functional brain connectivity with the amygdala,” said Joshua G. Corbin, Ph.D., interim director of the Center for Neuroscience Research at Children’s National Health System and the study’s co-senior author.

“Our study is one important step along the pathway to developing new biomarkers for autism spectrum disorder and, hopefully, predicting patients’ outcomes.”

The research team’s insights came through investigating multiple lines of evidence, including mining publicly available genome-wide data, researching with experimental models, and conducting neuroimaging studies with ASD patients.

All told, the project is the result of six years of painstaking research and data collection, researchers said. This also includes banking patients’ saliva samples collected during clinical visits for future retrospective analyses to determine which genetic mutations were correlated with behavioral and functional brain deficits, Corbin said.

“We homed in on this project to look at about a dozen genes to assess correlations and brought in experts from genetics and genomics at Children’s National to sequence genes of interest,” he added.

“Linking the bench to bedside is especially difficult in neuroscience. It takes a huge amount of effort and dozens of discussions, and it’s very rare. It’s an exemplar of what we strive for.”

Source: Children’s National Health System