Washington, March 3 : A specific gene variant that links increased genetic risk for autism with gastrointestinal (GI) conditions has been identified by scientists at the University of Southern California (USC) and Vanderbilt University.

Dr. Pat Levitt, director of the Zilkha Neurogenetic Institute at the Keck School of Medicine of USC and chair-designate of the Department of cell and neurobiology, says that the research team's findings suggest that disrupted signalling of the MET gene may contribute to a syndrome that includes autism and co-occurring gastrointestinal dysfunction.

Autism is a developmental disorder characterized by deficits in communication abilities, social behaviour disruption and inflexible behaviour, according to background information in an article published in the journal Pediatrics.

Levitt and lead study author Dr. Daniel Campbell say that while gastrointestinal conditions are common among individuals with autism, researchers have long debated whether co-occurring GI dysfunction represents a unique autism subgroup.

"Gastrointestinal disorders don''t cause autism. Autism is a disorder of brain development. However, our study is the first to bring together genetic risk for autism and co-occurring GI disorders in a way that provides a biologically plausible explanation for why they are seen together so often," Levitt says.

The researcher highlights the fact that the MET gene in the brain is expressed in developing circuits that are involved in social behaviour and communication, and that disturbances in its expression result in alterations in how these critical circuits develop and mature.

Levitt further says that research indicates that MET also plays an important role in development and repair of the GI system.

For their research, the team studied medical history records from 214 families in the Autism Genetic Resource Exchange (AGRE), and found that a variant in the MET gene was associated with autism specifically in those families where an individual had co-occurring autism and a GI condition.

According to Levitt, the study takes the research team a step further towards understanding the complex genetic risks for autism.

The researcher, however, concedes that further research is required, as different combinations of genes are likely to result in different types of autism features.

"We believe that there are other genes that will help identify different subgroups of individuals who have autism spectrum disorder. We also believe that there needs to be research looking at whether the children with co-occurring GI dysfunction and autism have unique features that will help us predict what treatments will be best for them," he says. (ANI)