Some people are just naturally good at cheating. That is, they're born with a gene that allows them to take steroids, but pass traditional tests—without any of the designer masking agents that many athletes have turned to. And in a lot of leagues, that's as good as a license to dope your brains out.
The Daily Mail has a good writeup of the gene, UGT2B17, from over the weekend. It's found in varying amounts of the population—an estimated* one in ten caucasian people, 22 percent of people of African descent, over 66 percent (!!) of Asians—and can totally mask the use of some of the most common performance-enhancing drugs.
Here's how it works: The standard drug test in sports is called a T/E test. It compares the level of testosterone in your body to the level of epitestosterone, another hormone. Typically, the upward limit in sports is 4-to-1, testosterone to epitestosterone. But UGT2B17 keeps the ratio of T and E low naturally—even while testosterone levels rise. Meaning anyone with the gene could load up on testosterone and not worry about the tests.
Testosterone is a convenient thing for an athlete's body to mask, since it flat out works. There are reams of stories and data about the effects of testosterone—the hormone all the original steroids affected—and its effect on muscle density and recuperative benefits. Simply, muscle growth, endurance, and recovery all get a boost. We've known this forever, but it bears repeating since sports leagues and committees have spent the past several years explaining how there is now testing in place, and PEDs are being stamped out. And now here's a gene, a basic, unalienable part of a huge portion of humans, that negates the test many leagues choose to use.
Of course, this gene isn't the only way to beat the T/E test. The standard upward limit of a four-to-one ratio is relatively easy to beat if you have a mind to. For example, the BALCO system—"the clear" and "the cream"—involved a paste (the cream) that was just testosterone mixed with epitestosterone. It worked, and the elevated levels were never picked up. That's especially easy in sports, where many athletes have naturally high levels of testosterone anyway—it's part of what makes them exceptional. So to test positive, they need to test at significantly higher levels than other professional athletes, who are already higher than most humans. This leaves a ton of room for error.
There are better tests, and testing methods, though. They just aren't widely used outside of the strictest regions of sports. Biological passports are probably the best. Those are, simply, a long term profile of what's in an athlete's body. They let you observe changes to a person's biological makeup over a long period of time—a longitudinal study for single athletes, essentially. So if you start screwing with this hormone or that in the middle of your career, it's going to be obvious.
There are a number of other, more complex tests that could also work. But peeing in a cup is still the industry standard, because, well, no reason really. It's easy, and doesn't require picking fresh fights with the unions. Which, again, we know. It's just now we also know that in addition to the very slightest precautions being enough to skirt by the test, there's a whole segment of people out there that can just take steroids and pass the most common steroid test in use. [Daily Mail]