A leading scientist has made a breakthrough in understanding the causes of autism, prompting hopes that new tests and treatments could be made available.
Research from the University of California, Los Angeles, shows for the first time how a gene linked to autism rewires the brain's connections.
In children with the gene, the brain's frontal lobe, which plays a key role in learning, is poorly linked to the rest of the brain, says a report in the journal Science Translational Medicine.
Autism and related conditions such as Asperger's syndrome affect more than one in 100 British children – 10 times more than 30 years ago.
The condition is still little understood, and at the moment diagnosis is a lengthy and stressful process of hospital visits and psychological tests. While drugs can be given to control symptoms such as aggression or hyperactivity, there is no cure.
Talking about the new findings, researcher Ashley Scott-Van Zeeland said: 'In children who carry the risk gene, the front of the brain seems to mainly talk to itself.
'It doesn't communicate as much with other parts of the brain and lacks long-range connections to the back of the brain.'
There are also fewer connections between the frontal lobe and the left side of the brain, which is key to speech and understanding language.
The new findings have been hailed as a key piece in the autism puzzle, and experts believe that learning more about how the gene (CNTNAP2) is linked to autism could lead to new tests for the condition and could also help with the design of drugs that strengthen the connections between brain regions.
It is thought that more than 30 genes contribute to autism, with some combinations setting the scene for the condition to be triggered by environmental factors such as pesticides and infections.