MONDAY, March 2 (HealthDay News) -- Researchers have identified a gene variant that is associated with both autism and gastrointestinal problems in individuals with autism.

The finding may represent early identification of a sub-type of autism.

"This association was not present in another group who have autism and don't have gastrointestinal problems," said study author Dr. Daniel B. Campbell, a research assistant professor of pharmacology at Vanderbilt University in Nashville. "We think we're subdividing types of autism in a way that's finally useful."

The report was published in the March issue of Pediatrics.

Autism is widely recognized to be not one condition, but a collection of very heterogeneous disorders. Many prefer to use the term "autism spectrum disorders" (ASD) to describe the variety.

Several studies have now shown an association between ASD and this specific genetic variant.

The study authors put this together with the fact that 30 percent to 70 percent of children with autism have GI problems and the fact that the MET C gene is involved with both brain development and how the GI system functions.

"It's involved in how well it repairs itself, how well it responds to insults, taking in foods that upset the stomach," Campbell explained. "We wondered if this MET gene variant that we'd identified two years ago might be involved specifically in a subset of these patients who have both autism and a GI problem."

The authors looked at medical histories and genetic profiles of 918 individuals with autism from 214 families.