Column 3 min read

Genome Culture: DNA Testing of Athletes, a Disaster in the Past, May Be Required of Future Olympians

Defining what normal DNA is for an athlete may be impossible.

By Laura Hercher featured image Dmitry Fisher / Getty Images

The athletes in South Korea — twisting, turning, and dropping out of the sky — seem almost superhuman. Is it possible that they are? Is it possible that they are the product of genetic engineering — faster, higher, and stronger by design?

No, it is not. But what’s impossible today may be plausible tomorrow, and the gatekeepers to Mt. Olympus, the World Anti-Doping Agency (WADA), have been thinking ahead. Their list of forbidden enhancements has been modified to include  “the use of gene editing agents designed to alter genome sequences and/or the transcriptional or epigenetic regulation of gene expression.” And as a recent article in Wired suggests, future Olympians may be required to submit their genetic code for analysis as a part of the agency’s effort to prevent athletes from tinkering with their own genes.

Analysis of the genetic code to catch cheaters? Time to ask Genome Culture’s favorite recurring question!

What could possibly go wrong?

Genetic analysis of athletes is not new. It began in 1968, in response to suspicions that a few of the female athletes were actually men in disguise. Genetic testing was suggested as a more highbrow alternative to the first generation sex test, which involved eyeballing genitalia. But checking for X chromosomes turned out to be even more fraught.

Over the course of the next 30 years, never — not once — did genetic testing for sex do what it was designed to do, which was catch cheaters. What it did achieve, in a clumsy and often cruel manner, was identify individuals with disorders of sexual development and other genetic conditions, most of which had no bearing on their athletic performance.

Checking for two X chromosomes was supposed to be a definitive identifier of femaleness. But women with Turner’s syndrome have only a single X, and women with androgen insensitivity syndrome (AIS) have an X and a Y chromosome. AIS affects the body’s ability to perceive testosterone, so women with this condition produce high levels of male hormones to which their bodies are oblivious. They may not even know they have AIS. It certainly does not benefit them athletically.

Still, in 1986, the 60-meter hurdles champion of Spain, a woman named Maria Jose Martinez-Patina, faced public shaming and discrimination when a test revealed her to have XY chromosomes. She was counseled to feign injury and retire. When she refused, she was stripped of her national title, lost her athletic scholarship, and was kicked out of the athletes’ residence.

“I knew I was a woman,” Martinez-Patina wrote in 2005, describing her experience. “I could hardly pretend to be a man; I have breasts and a vagina. I never cheated.”

The take-home point, Olympic organizers, is that “normal” is a very slippery concept when it comes to genetics. Defining one version of the genetic code as “normal” is like putting Jell-O in a box and claiming it’s a cube. And by definition, Olympic-level athletes are outliers. Whatever normal is, they are not.

Theoretically, having genetic information may help WADA track athletes over time, so the agency can identify changes to their genes or gene expression patterns. This sounds like it makes sense, but again, it assumes a narrow band of normal. A test looking for engineered genetic variation may be just as likely to pick up mosaicism or other natural genetic phenomena. The genome is not a clean, well-lighted place; it is more of a dusty attic. Go looking for one thing, and you are likely to find something else.

One thing is certain: introduce genetic testing of athletes, and mistakes will be made. If it happens at the Olympics, these mistakes will occur in a context of high stakes and intense media attention. It will be almost impossible to protect the athletes’ privacy or to contain rumors and innuendo. They may find evidence of cheating but they will also find variations we cannot explain; history suggests we may not always be able to tell the difference.