The Future (cont.)
Posted: Tuesday March 11, 2008 12:27PM; Updated: Wednesday March 12, 2008 10:52AM
Since the gene genie escaped from the bottle a decade ago, researchers have discovered dozens more genes that appear to affect athletic performance. This is old news in the rodent community. Scientists have created mice whose bodies are flooded with oxygen-carrying red blood cells, creating greater endurance. Other mice have been engineered to produce extraordinary amounts of growth hormone, while still others metabolize fat and carbs in such a way that they can live like couch potatoes yet run like marathoners.
Significant safety hurdles remain before gene therapy is widespread for humans. The most efficient means of delivering a synthetic gene is by attaching it to a virus that shuttles it into human cells. Viruses are great at that. They can also trigger the immune system in a way that can lead to fatal results. In 1999 Jesse Gelsinger, an 18-year-old with a rare liver disease who had volunteered for a gene-therapy trial, died from a massive immune response to the virus used in the treatment. And the dangers extend beyond the immune system. In a gene-therapy trial in France, 12 boys were successfully treated for X-linked severe combined immunodeficiency, commonly known as Bubble Boy syndrome, but at least three of them developed leukemia.
One delivery method -- flushing the bloodstream with the desired gene -- is simple enough, says Sweeney, that it could be achieved by a clever undergrad in a molecular biology lab. The method is not very efficient and hasn't been thoroughly tested, but it hints at the possibilities for the spread of gene tampering in sports. Despite the unknowns and the dangers, chances are good that someone at the Beijing Olympics in August, someone willing to weigh his or her mortality in gold, will have undergone gene transfer in an attempt to enhance performance. "Even when I tell them it's not safe," Sweeney says, "some athletes are willing to try anything."
The signs are ominous. In January 2006, during German track coach Thomas Springstein's trial on charges of providing performance-enhancing drugs to minors, evidence emerged indicating that Springstein had attempted to procure Repoxygen, a gene-therapy drug developed to treat anemia by prompting cells to produce EPO and, in turn, red blood cells. (He was found guilty of giving illegal substance to minors and received a 16-month suspended sentence.) In addition, Mauro Di Pasquale, the 1976 world powerlifting champion and an Ontario physician who has written several books on sports doping, says he knows that athletes are experimenting with gene doping, with the help of Chinese doctors and researchers.
Human data relating to myostatin has been hard to come by. Soon after his discovery, Lee attempted to identify potential test subjects with natural mutations in their myostatin genes. He placed an ad in Muscle and Fitness, and close to 1,000 muscle-bound men and women responded. But after collecting samples from 150 of them, he has yet to find a single one with the myostatin mutation he had engineered in his mice.
From his study of Belgian Blue cattle, Lee knew the mutation could occur naturally. A cross between the Shorthorn and the Holstein, which have been bred for some 150 years, these massive animals look as if their skin has been stuffed with watermelons. Lee got in touch with Dee Garrels, owner of the Lakeview Belgian Blue Ranch in Stockton, Mo., who sent him samples for testing. Garrels knew Belgian Blues were strong -- her 2,500-pound bull once ripped a metal restraining gate off its hinges with its horns to get at a cow in heat -- and Lee found out why. He discovered that they had mutations in their myostatin genes.
Lee didn't see the power of a human myostatin mutation until Markus Schuelke contacted him in 2003. A pediatric neurologist in Berlin, Schuelke had been summoned three years earlier to examine a jittery baby in the nursery at Charité hospital in Berlin, where he was taken aback by the newborn's chiseled calves and sculpted quads. By the age of four the boy could hold up a pair of 6.6-pound dumbbells at arm's length. Schuelke had been monitoring the boy's development, and he got in touch with Lee, who confirmed the boy had mutations on both myostatin-coding genes, leaving no detectable amount of the protein in his body.