Gene therapy could help athletes cheat

Sportsmen and women could soon be using undetectable genetic enhancement techniques to bypass the increasingly strict doping rules in world sport, it was claimed yesterday.

Unscrupulous athletes would be able to apply the latest scientific advances illicitly to enhance their performance with gene therapy injections to make their muscles bigger and stronger than those who rely on physical training alone. Lee Sweeney from the University of Pennsylvania in Philadelphia has demonstrated that the use of the injections in mice can improve muscle strength by up to 30 per cent without any additional exercise.

When he carried out similar experiments on rats, the injected muscle became almost twice as strong as the uninjected muscle - suggesting that the genetic enhancement of athletes, on top of training, would prove unbeatable.

Dr Sweeney said it was inevitable that someone would try the same on athletes in the hope of producing a doping method that cannot be detected by any test available today.

He told the American Association for the Advancement of Science in Seattle: "This is but one example of a number of potential gene therapies that are being developed with disease treatment as the goal, but if given to a healthy individual would provide genetic enhancement of some trait. As these developments go forward, they inevitably will find their way into the healthy population. The prospects are especially high that muscle-directed gene transfer will be used by the athletic community for performance enhancement, just as many drugs are used and abused today."

The technique uses a gene for insulin-like growth factor which when injected with a virus into a muscle becomes incorporated into the genes of the muscle tissue causing them to grow. In medicine the technique could prove useful in treating a range of muscle-wasting diseases, such as muscular dystrophy, and it could also be used to deal with muscle weakness in old people. One injection of the genes for the growth factor lasted a lifetime and older animals did not experience the muscle decline normally seen in ageing animals, including humans.

"The fact that we had seen not only beneficial effects in old animals and animals with muscle disease, but also muscle growth in young sedentary animals, suggested the possibility that such a treatment would lead to genetic enhancement of muscle performance," he said.

Dr Sweeney said it was unclear what the risks could be and added that they may include increased heart problems and possibly cancer. "In many cases, policing such abuse in the sports community will be much more difficult than in the case of drugs, since detection will be difficult," he said.