Background:  Understanding how genetic variation leads to changes in brain circuitry underlying social behaviour is a critical issue in autism research.  A common variant in the autism-linked gene known as MET has been identified as a genetic factor that may increase both the risk and severity of ASD. The autism-linked MET variant can be found in both unaffected individuals and people with Autism Spectrum Disorder (ASD).

What’s new:  Researchers in Los Angeles, CA imaged the brains of 75 children and adolescents with ASD and 87 unaffected individuals, some of whom carry the risk variant of the MET gene, to determine if the presence of this risk variant affects brain circuitry. The researchers reported in the 6 September 2012 issue of Neuron that both unaffected individuals with the MET risk variant and those with ASD who harbor the same variation in the MET gene showed noticeable changes in how the brain responded to social stimuli. The researchers also identified abnormalities in brain connectivity, both in terms of function and structure.  These effects were significantly more pronounced in individuals with ASD.

Why it’s important:  The results of this study offer insight into how genetic variation affects brain circuitry in children with ASD as well as unaffected individuals. The circuitry changes caused by the MET risk variant can lead to an increased risk or increased severity of ASD.

How Do Autism Risk Genes Affect Brain Function?

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