ACTN3 R/X gene polymorphism across ethnicity: a brief review of performance gene

Abstract

Alpha-actinin-3 (ACTN3) gene is one of the most extensively investigated genes associated with human physical performance. The ACTN3 gene via ACTN3 R/X gene polymorphism codes the ACTN3 protein proteins that are localized at the boundaries of sarcomeres in the contractile apparatus of muscle Z disk. The ACTN3 R allele codes for functioning ACTN3 gene that results in the production of ACTN3 protein, while incomplete sequence in the ACTN3 X allele, preventing the production of that protein. Given these different physiological functions, possession of the ACTN3 R and X alleles may grant beneficial effects of strength/power and endurance activities, respectively. It has remained uncertain if human physical performance is indeed influenced by ACTN3 R/X gene polymorphisms as some studies have failed to demonstrate positive findings. It has been speculated that the inconsistencies observed in the present findings may be due to ethnicity differences as the distributions of ACTN3 R/X gene polymorphism has been reported to vary across ethnic groups in general populations worldwide. Therefore, the aim of this review is to provide a brief review of ACTN3 R/X gene polymorphism, including distribution pattern across ethnicity and its association on human physical performance based on population studies. Therefore, this review could serve as the basis for future research towards a better comprehension of the involvement of the ACTN3 R/X gene polymorphism on human physical performance across different ethnic groups.