Previous reports have shown a lower proportion of the ACTN3 X/X genotype (R577X nonsense polymorphism) in sprint-related athletes compared to the general population, possibly attributed to impairment of muscle function related to alpha-actinin-3 deficiency. In the present study, we examined the frequency of the X/X genotype in both Black and White elite-level bodybuilders and strength athletes in comparison to the general population. A reference population of 668 Whites (363 men and 305 women) and 208 Blacks (98 men and 110 women) was genotyped for the ACTN3 R577X polymorphism. Strength athletes (52 white and 23 black; 4 women) consisting predominantly of world class and locally competitive bodybuilders, and elite powerlifters were recruited and similarly genotyped. Significantly lower X/X genotype frequencies were observed in the athletes (6.7%) vs controls (16.3%; P=0.005). The X/X genotype was significantly lower in White athletes (9.7%) vs controls (19.9%; P=0.018). No black athletes (0%) were observed with the X/X genotype, though this finding only approached statistical significance vs controls (4.8%; P=0.10). The results indicate that the ACTN3 R577X nonsense allele (X) is under-represented in elite strength athletes, consistent with previous reports indicating that alpha-actinin-3 deficiency appears to impair muscle performance.

中文翻译：

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ACTN3 R577X 无意义等位基因在精英水平的力量运动员中代表性不足。

先前的报告显示，与普通人群相比，短跑相关运动员中 ACTN3 X/X 基因型（R577X 无意义多态性）的比例较低，这可能归因于与 α-actinin-3 缺乏相关的肌肉功能受损。在本研究中，与普通人群相比，我们检查了黑人和白人精英级健美运动员和力量运动员的 X/X 基因型频率。针对 ACTN3 R577X 多态性对 668 名白人（363 名男性和 305 名女性）和 208 名黑人（98 名男性和 110 名女性）的参考人群进行了基因分型。力量运动员（52 名白人和 23 名黑人；4 名女性）主要由世界级和当地有竞争力的健美运动员组成，并招募了精英举重运动员并进行了类似的基因分型。在运动员中观察到显着较低的 X/X 基因型频率 (6. 7%）与对照（16.3%；P=0.005）。白人运动员 (9.7%) 的 X/X 基因型显着低于对照组 (19.9%；P=0.018)。没有观察到具有 X/X 基因型的黑人运动员 (0%)，尽管这一发现与对照组相比仅接近统计显着性 (4.8%；P=0.10)。结果表明 ACTN3 R577X 无意义等位基因 (X) 在精英力量运动员中代表性不足，这与之前的报告一致，表明 α-actinin-3 缺乏似乎会损害肌肉性能。