Gene Doping: The Hype and the Harm

Methods of gene therapy or doping

The general goal of gene therapy is to promote expression of a functional gene in an unhealthy individual to correct a disease caused by an underlying genetic mutation. The ideal gene therapy candidate is a monogenic condition caused by a nonfunctional or aberrant gene product, such as in Duchenne muscular dystrophy (DMD). In DMD, mutations in the dystrophin gene lead to absent, decreased, or dysfunctional dystrophin protein production. “Classic” gene therapy in this case would be the mechanism

Candidates for gene doping

What makes a gene a good candidate for doping? Obviously, the targets for gene doping would depend on the desired effect. Overexpression or underexpression of the gene product should enhance traits that are desirable for peak athletic performance. For endurance sports, such as long distance running or swimming, genes that bolster oxygen production or usage and delay fatigue would be the likely candidates. For sports in which strength or agility provide the competitive advantage, genes involved

Gene doping in practice—animal models

Animal models of gene doping have provided a wealth of information on the positive and negative effects of this procedure. Methods of successful gene transfer to adult animal cells have been demonstrated, and the successes of these transfers have been documented.¹⁵ For example, gene doping with IGF-1 has proven successful in mouse models, whereby a discernible increase in muscle mass and strength was noted even months after the treatment concluded. These same studies showed that combining gene

Gene doping in theory—human models

Although animal studies have been successful in demonstrating gene doping effects, the transfer of this technology to humans is met with considerable logistical and practical limitations. In mouse models, high vector doses were required to induce significant effects. It is not clear how high a vector dose would be required for human gene doping or if humans have a similar capacity to tolerate these vector doses safely and effectively.⁵ Are current laboratory techniques and resources capable of

Risks of gene doping

The risks associated with gene therapy in a regulated, controlled setting are still being defined. Results of gene therapy trials performed in the 1990s indicated both a substantial variability in response to vectors and a nonlinear relationship between vector dose and toxicity. The death of an 18-year-old volunteer in a pilot study of gene therapy was attributed to systemic inflammatory response syndrome caused by an immune response to the adenoviral vector used.²⁴ Therefore, the risks

Detection strategies

The only way to address the possibility of gene doping detection is to stay current with scientific techniques and potential avenues for abuse of gene therapy. WADA included gene doping in their list of banned methods in 2003, continues to monitor developments in this area closely, and sponsors research into detection strategies.³ To be successful, doping detection needs to be accessible, fast, and reliable: 3 significant challenges when dealing with gene doping. For example, if a gene doping

Summary

The advancement of genetic technologies that have lead to the exciting treatment possibilities of gene therapy has also opened the door for their abuse as a performance-enhancing agent. Although gene doping may be a desirable cheating method because of the inherent detection challenges, its effects are still largely unknown and potentially lethal.

The physical, ethical, and societal pitfalls of performance-enhancing doping are numerous. Gene doping adds another level of concern not only in the