Massidda Myosotis, Vona Giuseppe, Calò Carla M
Department of Experimental Biology, University of Cagliari, Cagliari, Italy.
Genet Test Mol Biomarkers. 2009 Jun;13(3):377-80. doi: 10.1089/gtmb.2008.0157.
The ACTN3 (R577X) gene encodes for a structural protein that is exclusively expressed in the Z-disc of type II muscle fibers. Homozygosis (577XX) for the stop codon in the ACTN3 polymorphism results in alpha-actinin-3 complete deficiency. Previous studies have shown low frequencies of the ACTN3 XX genotype in elite sprinters compared to the general population. This study tests 35 Italian elite gymnasts and 53 controls. ACTN3 XX genotype (2.8% vs. 18.8%; p < 0.04) and X allele (27.1% vs. 43.3%; p < 0.04) frequencies were significantly lower in gymnasts compared to controls. The ACTN3 XX genotype was underrepresented in female and male gymnasts compared to controls, but was only significant for males (male: 0% vs. 16.1%, p < 0.04; female: 5.5% vs. 22.7%, p = 0.39). These results suggest that alpha-actinin-3 is beneficial to skeletal muscle function in generating forceful contractions at high velocity. In conclusion, our results associated the ACTN3 R577X polymorphism with male and possibly female elite gymnastic performance.
α-辅肌动蛋白3（R577X）基因编码一种结构蛋白，该蛋白仅在II型肌纤维的Z盘表达。ACTN3多态性中的终止密码子纯合子（577XX）导致α-辅肌动蛋白-3完全缺乏。先前的研究表明，与普通人群相比，精英短跑运动员中ACTN3 XX基因型的频率较低。本研究对35名意大利精英体操运动员和53名对照者进行了检测。与对照组相比，体操运动员的ACTN3 XX基因型频率（2.8%对18.8%；p<0.04）和X等位基因频率（27.1%对43.3%；p<0.04）显著较低。与对照组相比，ACTN3 XX基因型在女性和男性体操运动员中均未充分体现，但仅在男性中具有显著性差异（男性：0%对16.1%，p<0.04；女性：5.5%对22.7%，p = 0.39）。这些结果表明，α-辅肌动蛋白-3有利于骨骼肌在高速产生强力收缩时的功能。总之，我们的结果将ACTN3 R577X多态性与男性以及可能的女性精英体操表现联系起来。
