Scientists have for the first time found direct evidence that defects in a particular type of brain receptor sometimes give rise to autism, according to research published 24 November in Molecular Psychiatry.Gamma-aminobutyric acid (GABA) receptors control inhibitory signals that calm electrical storms in the brain. Researchers have long known that improper GABA signaling plays a role in epilepsy, and emerging evidence implicates the system in autism spectrum disorders.A few studies have shown that common variants of the GABRB3 gene, which encodes a protein that helps build GABA receptors, are more widespread among people with autism than among healthy controls. But the new report is the first to find a rare, functional variant of GABRB3 in families with autism."There has been a tremendous amount of evidence linking this particular gene with autism, but it's all considered somewhat circumstantial evidence," says Timothy DeLorey, senior research scientist at the Molecular Research Institute in Palo Alto, California, who was not involved in the work. "This study shows a direct causal effect between this gene and autism."Read more at...SFARI, December 2009.