The Olympic Games and Genes

Just two weeks before the scheduled start of the Beijing Olympics, a German film crew caught a Chinese doctor on film offering to give athletes stem cell treatments to enhance their performance.

The reporter has since refused to identify the doctor on the tape and China has vehemently denied the documentary’s claims about the availability of so-called “gene doping” in this year’s Olympics host country. Still, the specter of a new kind of cheating hovers over the Games.

For years it’s been known that some athletes have resorted to using performance-enhancing drugs to live up to the Olympic motto of “faster, higher, stronger.” But the possibility of a new, undetectable kind of cheating made possible by advances in gene therapy has the World Anti-Doping Agency (WADA) worried.

Take for example the case of Italian cyclist Riccardo Ricci, who was recently thrown out of the Tour de France after tests showed he’d injected the hormone erythropoietin (also known as EPO) to get more oxygen into his bloodstream. In a world where gene doping is a reality, Ricci could have gotten away with enhancing his oxygen capacity by inserting the EPO-producing gene into his genome, gifting him with what would have appeared to doping tests to be a natural advantage.

WADA is taking steps to counter potential gene doping cheaters at the 2012 Olympics by funding researchers around the world to develop tests that could determine if athletes are using gene therapy techniques to improve their performance.

For example, researchers in Canada are working on a test that checks changes in gene activity to find out if athletes have tinkered with their genome, inserting the EPO-producing gene to increase their bodies’ oxygen production. They hope to be able to have a sample test ready by next year.

French and American researchers are also working on a test to determine if athletes have doped their DNA. Their test is expected to compare the number of copies of a specific gene in an athlete suspected of gene doping against the number of copies of the same gene in the average person. A preliminary survey on the practicality of their idea is due this year.

Even as they work on countering gene doping, scientists and sports officials alike are finding that genetics may already have an impact on current drug doping tests.

In the July issue of the Journal of Clinical Endocrinology & Metabolism, Swedish researchers identified a variation of the UGT2B17 gene found in two-thirds of Asians and 10 percent of Caucasians that caused a negative result on the standard testosterone doping test, even if the men tested were actually taking the steroid.

This latest finding suggests that even if athletes don’t resort to gene doping, they may have genes that allow them to dope with drugs and not get caught.