Scientists have shown how a single protein may trigger autistic spectrum disorders by stopping effective communication between brain cells.
The team from Duke University in North Carolina created autistic mice by mutating the gene which controls production of the protein, Shank3.
The animals exhibited social problems, and repetitive behaviour – both classic signs of autism and related conditions.
The Nature study raises hopes of the first effective drug treatments.
Autism is a disorder which, to varying degrees, affects the ability of children and adults to communicate and interact socially.
While hundreds of genes linked to the condition have been found, the precise combination of genetics, biochemistry and other environmental factors which produce autism is still unclear.
Each patient has only one or a handful of those mutations, making it difficult to develop drugs to treat the disorder.
Shank3 is found in the synapses – the junctions between brain cells (neurons) that allow them to communicate with each other.
The researchers created mice which had a mutated form of Shank3, and found that these animals avoided social interactions with other mice.