London, Nov 4 (IANS) Scientists have edged a step closer to unravelling the riddle of autism - they have found 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, acording to the journal Science Translational Medicine.

Researcher Ashley Scott-Van Zeeland, from the University of California, Los Angeles, US, said: "In children who carry the risk gene, the front of the brain seems to mainly talk to itself," reports the Daily Mail.

"It doesn't communicate as much with other parts of the brain and lacks long-range connections to the back of the brain."

There were also fewer connections between the frontal lobe and the left side of the brain, which is key to speech and understanding language.

With its cause unclear, diagnosis is a lengthy and stressful process of hospital visits and psychological tests.

And while drugs can be given to control symptoms such as aggression or hyperactivity, there is no cure.

Researcher Daniel Geschwind, an expert in the genetics of autism, said: "This is a key piece of the puzzle we've been searching for.

"Now we can begin to unravel the mystery of how genes rearrange the brain's circuitry not only in autism but in many related neurological disorders."