Prevalence of ACE I/D and ACTN3 R577X genetic polymorphisms in Taekwondo athletes

Background: Among genetic variants associated with physical performance, ACTN3 R577X and ACE I/D are among the most studied. However, their prevalence and functional significance in combat sports like Taekwondo remain underexplored. Objective: To evaluate the prevalence of ACTN3 R577X and ACE I/D polymorphisms in Taekwondo athletes and controls, and to investigate their association with competitive level and belt ranking. Methods: A total of 204 individuals (119 athletes and 85 controls) were genotyped via PCR using DNA from buccal cells. Genotype distributions were analyzed for Hardy-Weinberg equilibrium (HWE). Associations with performance level and belt ranking were tested. A "two loci profile" variable was created by combining genotypes into power-, endurance-, or mixed-oriented categories. Results: ACE I/D genotypes in athletes deviated from HWE due to a higher prevalence of the DD genotype (32.2%, P = 0.017). In contrast, controls were in HWE for ACE but not for ACTN3. The DD genotype was more common among national-level competitors and black belts. The ACTN3 RR genotype also showed higher frequency among black belts but without statistical significance. When combining ACE DD and/or ACTN3 RR genotypes, black belts showed significantly greater prevalence than other ranks (37.5% vs. 14.3%, P = 0.038). Conclusion: Genotypes related to strength and power appear more frequent among higher-performing Taekwondo athletes. These results contribute to the understanding of a synergetic action of two loci in combat sports and may support future applications in personalized training and talent identification.