Gene-a-dope

Science gives us a “policy forum” this week on gene doping. The lead author, Theodor Friedmann, is the chair of the “Gene Doping Expert Group” at the World Anti-Doping Agency.

The essay describes the current potential of gene doping, and is a good short review. I found the paragraphs on “marketing gene doping” very interesting:

Athletes are an especially vulnerable population in the marketing of performance enhancement (31). Reputable athletes or coaches with little knowledge of genetics are at a disadvantage in assessing "scientific" claims that appear in advertisements. Marketing is particularly worrisome when the science is still a work in progress, when a person's health can be adversely affected, and when consumer knowledge about genetics is low. Although advertisements promoting products that promise to enhance athletic performance have pervaded the Internet for many years, recently it has become home for advertisements that promote products to "alter muscle genes...by activating your genetic machinery" (32), or that state "your genetic limitations are a thing of the past!" (33) or "Finally, every bodybuilder can be genetically gifted!" (34).

These are people who make easy targets for nutrigenomics and other questionable areas of “health enhancement.” A large number of amateur bodybuilders and fitness enthusiasts create a “gray market” supporting questionable products, and these products themselves support the ecosystem of effective performance enhancement drugs. They also create a lot of biochemical noise for those who want to find new tests for performance enhancers.

The essay includes a few paragraphs that describe the prospects of future detection of gene doping. It may be very difficult. Detecting some synthetic performance-enhancing agents requires the cooperation of primary producers, who add tracers to their products. Gene doping might enhance performance for periods months or years after the vector is administered, and may not require dosage that would significantly alter isotopic or chemical signatures, even if they contained such tracers. The authors suggest that the incidental biochemical effects of gene doping might enable the identification of a “signature” of such products:

For instance, exposure of murine myoblasts to IGF-1 has been shown to induce transcriptional and proteomic changes that may eventually constitute a "signature" specific for exogenous IGF-1 exposure (29, 30). Of course, the application of these kinds of global assays would require rigorous validation of a connection with specific doping agents or methods.

I am very skeptical – it’s likely that the “signature” of a doped individual will not differ appreciably from the normal variability of tissue metabolism, particularly in the subset of high-performance athletes. Still, it may be possible to find one particular tissue type that provides a high-information-content message about normal versus doped processes. I just think that a lot of innocent athletes are likely to get snared in this net as it closes in on clinical validation.

References:

Friedmann T, Rabin O, Frankel MS. 2010. Gene doping and sport. Science 327:647-648. doi:10.1126/science.1177801