Intellectual gifts and certain brain disorders are closely related

Some people with autism have amazed experts with their outstanding memories, mathematical skills or musical talent. Now scientists have found that the genes thought to cause autism may also confer mathematical, musical and other skills on people without the condition.

The finding has emerged from a study of autism among 378 Cambridge University students, which found the condition was up to seven times more common among mathematicians than students in other disciplines. It was also five times more common in the siblings of mathematicians.

If confirmed, it could explain why autism - a disability that makes it hard to communicate with, and relate to, others - continues to exist in all types of society. It suggests the genes responsible are usually beneficial, causing the disease only if present in the wrong combinations. "Our understanding of autism is undergoing a transformation," said Professor Simon Baron-Cohen, director of the autism research centre at Cambridge, who led the study.

"It seems clear that genes play a significant role in the causes of autism and that those genes are also linked to certain intellectual skills."

Scientists have long been intrigued by the apparent association between autism and intellectual gifts in specific fields. This has made autism a hot topic in popular culture, from films such as Rain Man, which starred Dustin Hoffman and Tom Cruise, to books such as The Curious Incident of the Dog in the Nighttime.

Some people with autism have become renowned for their creativity. The British artist Stephen Wiltshire, 34, was mute as a child and diagnosed with classic autism. He began drawing at the age of five and soon completed cityscapes. One of his feats was to draw a stunningly detailed panoramic view of Tokyo from memory after a short helicopter ride. He has since opened a gallery.

Autism and the related Asperger's syndrome are among the commonest mental afflictions, affecting about 600,000 Britons. Boys are four times as likely as girls to develop it. Autistic people can have special skills but they also tend to suffer from anxiety, obsessive behaviour and other problems that far outweigh any advantages.

The fact that autism runs in families shows that it is partly genetic in origin, but evolutionary theory suggests genes causing such a debilitating conditions ought to have been weeded out of the population. The Cambridge study hints at why this has not happened, suggesting that with variations in the way they are combined, such genes are beneficial.

On their own, such studies have to be treated cautiously because the numbers involved are small. In the Cambridge study, seven of 378 maths students were found to be autistic, compared with only one among the 414 students in the control group.

Other studies, however, have found similar patterns. Baron-Cohen, whose cousin Sacha Baron Cohen is the comic actor behind the Ali G and Borat characters, said: "Separate studies have shown that the fathers and grandfathers of children with autism are twice as likely to work in engineering. Science students also have more relatives with autism than those in the humanities."

His research, set out last week in a meeting at the Royal Society, coincides with separate research showing nearly a third of people with autism may have "savant" skills.

Patricia Howlin, professor of clinical child psychology at the Institute of Psychiatry at King's College London, studied 137 people with autism; 39 of them (29%) possessed an exceptional mental skill. The most common was outstanding memory.

She said: "It had been thought that only about 5%-10% of people with autism had such skills, but nobody had measured it properly, and it seems the number is far higher. If we could foster these skills, many more people with autism could live independently and even become high achievers."

The idea that autism may have positive aspects is finding favour among some of those with the condition. Some resent being labelled disabled and have begun describing those without autism as "neurotypicals" to make the point that they could be the ones missing out.

Professor Allan Snyder, director of the centre for the mind at the University of Sydney, said: "Autism ranges from the classical picture of severe mental impairment at one end of the spectrum to Nobel prize-winning genius at the other. Both extremes have core autistic features, such as preoccupation with detail, obsessional interests and difficulties in understanding other people's perspectives."

Temple Grandin, 61, was diagnosed with autism as a child and is now professor of animal sciences at Colorado State University. She said: "People with autism have played a vital role in human evolution and culture. Before computers it would have taken someone with an autistic-type memory to design great cathedrals, while scientists such as Isaac Newton and Albert Einstein show every sign of having been autistic. The world owes a great deal to those who design and programme computers, many of whom show autistic traits."

For Baron-Cohen the next step is to find the genes linked with autism; he is working with Professor Ian Craig of King's College to scan the DNA of hundreds of autistic people - and of mathematicians.

For latest papers on autism research, go to www.autismresearchcentre.com

A concert at the Savoy Theatre in London's west end will tonight showcase musicians with autism, and an exhibition starting tomorrow at London's Institute for Contemporary Art (ICA) in the Mall features the art of people with autism. For details go to www.theambassadors.com/savoy. Autism Art and Music Details at: www.autismart.org

The Autism Research Centre has produced The Transporters, a DVD-based animation that helps autistic children to learn about emotions by looking at faces on mechanical vehicles. The Transporters DVD (aimed at children with autism) is available online at www.thetransporters.com