設(shè)在波士頓的優(yōu)越風險管理公司的一名常務(wù)董事史蒂夫·格蘭斯和他的同事胡安·恩里克斯7月18日在英國《自然》雜志網(wǎng)站撰文指出,，有越來越多證據(jù)表明,，世界頂級運動員都或多或少攜帶有一些特殊的“增強表現(xiàn)”的基因。例如，幾乎每個接受測試的奧運會男性短跑選手體內(nèi)都有a-輔肌動蛋白3（ACTN3）基因的577等位基因,，這種基因也存在于85%的非洲人以及50%的歐洲人和亞洲人體內(nèi),，不過，其他缺乏577等位基因的數(shù)十億人可能要重新評估自己想在奧運會上獲得獎牌的“美夢”是否切實可行了,。
未來的奧運會將出現(xiàn)三幅圖景,。第一幅場景是，奧運會將繼續(xù)成為那些天生擁有遺傳優(yōu)勢的運動員集中大展示的“舞臺”,。第二幅場景是,，利用讓步賽（給強者不利條件或使弱者略占優(yōu)勢的）——目前幾個非奧運項目的運動中也采用了這種比賽，來讓那些天生并不具備優(yōu)勢基因的運動員在賽場上獲得更加公平的競爭機會,。第三幅圖景是,，如果被證明是安全的，通過基因療法讓那些天生并不攜帶某些基因的運動員“升級”,，但“基因摻雜”這一醫(yī)學實踐目前被禁止使用,。
在未來的幾百年內(nèi)，我們可能都將生活在第一幅圖景中,?？茖W家們已經(jīng)證實，20多種基因變異與運動能力有關(guān),。例如,，攜帶有ACE基因的“I”變異的運動員，比沒有攜帶該變異的運動員更容易在爬上8000米高峰的比賽中取得成功,。尼泊爾加德滿都谷地雪爾帕人中,，有94%的人擁有“I”變異；而其他種族的人群中,，僅僅45%到70%的人擁有該變異,。這一變異會提高人的耐受力。對英國跑步運動員進行的研究發(fā)現(xiàn),，這種基因變異在那些耐力較好的運動員中最常見,。
但是，這樣的變異在人群中出現(xiàn)的幾率比較大,，因此，運動員們可能需要某些特定的基因變異才能獲得精英地位,。隨著越來越多的個人基因組被排序,，研究人員開始探究一些罕見的變異，這些變異會真正將超級運動員和世界級的運動員區(qū)分開來,。例如,，芬蘭的越野滑雪選手、七枚奧運會獎牌得主埃羅·門蒂蘭塔的紅細胞生成素受體（EPOR）發(fā)生的一種基因突變讓他能比正常人多產(chǎn)生25%的紅細胞，這就讓他的血液中攜帶著比普通人更多的氧氣,，因此,，有助于他在運動比賽中脫穎而出。(生物谷Bioon.com)
doi:10.1038/487297a
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Olympics: Genetically enhanced Olympics are coming
Juan Enriquez& Steve Gullans
Olympians can run faster, leap higher and lift more than 'normal' humans. Of course, such elite athletes earn their titles with an astonishing amount of hard work and support. But many also have some unearned advantages: the right genes.
There is growing evidence that world-class athletes carry a minimum set of particular 'performance-enhancing' genes. For instance, almost every male Olympic sprinter and power athlete ever tested carries the 577R allele, a variant of the gene ACTN3. About half of Eurasians and 85% of Africans carry at least one copy1 of this 'power gene'. The billion or so other people who lack the 577R allele might wish to reconsider their Olympic aspirations..
More and more genes are now being linked to athletic prowess, and future Olympic officials will have to wrestle with the implications. Are the games in fact a showcase for hardworking 'mutants'? And if Olympic rule-makers admit that the genetic landscape is uneven, should they then test every athlete and hold separate competitions for the genetically ungifted?
There are three basic scenarios for future Olympics. First, the competition could continue as a showcase of athletes born with genetic advantages. Another option would be to use handicaps — similar to those that are now used in several non-Olympic sports — to level the playing field for athletes who do not carry beneficial genes. A third option, if safe, would be to allow athletes who did not win the genetic lottery to 'upgrade' through gene therapy — a practice that is now banned as 'gene doping'.
We have been living in the first scenario for centuries. More than 200 gene variants are already associated with athleticism2. For example, carriers of the 'I' variant of the gene ACE are more likely than non-carriers to successfully climb an 8,000-metre peak3. The I variant is present in 94% of Sherpas in the Kathmandu Valley of Nepal4, but in only 45–70% of people of other ethnicities5. It is associated with increased endurance. A study of British runners found that it is most common in those who race the longest distances6.
Such variants occur frequently in the human population, and athletes probably need a subset of them to achieve elite status. As more individual genomes are sequenced, researchers will begin to detect some rare variants that differentiate truly superior champions from mere world-class athletes. Eero M?ntyranta had a mutation in the gene EPOR that caused him to produce extra red blood cells, boosting his oxygen-carrying capacity by 25–50% (ref. 7), which probably helped him to earn seven Olympic cross-country ski medals.
But how easily could scientists detect whether a variant is natural or introduced? Even 'gender-verification' testing to confirm the sex of female competitors has been problematic, given the natural biological variation among individuals8.
Olympic traditions change glacially, but eventually, what was once unthinkable becomes commonplace. Once upon a time, women were allowed to compete only in Olympic tennis, golf and croquet. Until the 1970s, paid athletes were banned from Olympic competition — now, professional basketball players compete for medals. And 'extreme sports' such as snowboarding and bicycle motocross have now become Olympics-worthy.
As officials struggle with the implications of genetic data and upgrades, we will probably see, initially, a set of draconian rules against gene modification. Will a competitor who was cured of sickle-cell anaemia by gene therapy as a child be excluded? How about someone cured of an EPOR defect through use of Eero M?ntyranta's natural variant?
Just as Oscar Pistorius, the Paralympic champion runner who was once banned from the Olympics because he uses leg prostheses, will now compete in London on the South African relay team, we expect that as genetic modification becomes more common, a gradual acceptance of safe genetic enhancements will follow. After all, we watch the games today to marvel at athletes who are 'faster, higher, stronger' — whether man or woman, amateur or professional, 'disabled' or not.
