A new study showing that gene therapy can increase both muscle bulk and power in monkeys has increased fears that such treatments could be abused in sport.
According to a report in Science Translational Medicine, gene therapy was used to suppress the production of the catabolic protein myostatin. Janaiah Kota and other researchers at the Nationwide Children's Hospital in Columbus, Ohio, found that monkeys treated in this way showed size and power increases in their muscles.
They are hoping that such therapies could correct the muscle weaknesses linked to neuromuscular disorders like muscular dystrophy and multiple sclerosis.
Drug companies are already conducting trials by using myostatin inhibitors in humans; early indications are that the results are promising.
The difficulty of testing for such therapies makes gene doping a serious issue for professional sports such as cycling. The practice has already been banned by WADA, but finding a test is likely to take some time.
The long-term effects of gene doping on the body are unknown, but theoretical risks include heart abnormalities and other potentially fatal consequences.