Articles : Association of the ACTN-3 Gene Polymorphism with Anaerobic Power Performance

Journal of Exercise Nutrition & Biochemistry 2004;8(3):275-280.

Abstract

The α-actinin is an actin-binding protein belonging to the spectrin protein superfamily. a-actinin-3(ACTN-3) expression is limited to skeletal muscle, especially Type Ⅱ muscle fiber. This gene has homozygosity for a premature stop codon resulting in a-actinin-3 deficiency. The deficiency in the type Ⅱ muscle is able to be compensated by a-actinin-2(ACTN-2). While that deficiency does not induce a disease phenotype, the ACTN-3 is highly conserved in evolutionary terms because of its functions independent of the ACTN2. Researchers have suggested that this trait is related to muscle function at the extremes of power performance. Therefore, we compared the relative frequencies of the ACTN-3 R577X polymorphism between anaerobic power athletes and control group. For this study, we recruited 158 sprint or power elite athletes and 414 healthy adults. The results of the current study showed significant differences in the genotype frequencies such that elite anaerobic power athletes have 4% higher of the RR genotype and 9% lower of the XX genotype than the healthy adults. With respect to the allele frequencies, the athletic group had significantly higher R allele frequency and significantly lower X allele frequency than the control group. In summary, these results suggest that the ACTN-3 R577X genotype may represent a genetic marker for anaerobic power performance.

Key Words: ACTN-3, performance-related candidate gene, polymorphism, anaerobic exercise, powerful exercise