Association between ACTN3 (R577X), BDKRB2 (-9/+9) and AGT (M235T) polymorphisms and physical performance in Brazilian junior handball players

Team handball performance relies on physical and technical abilities, influenced by environmental and genetic factors. Variants in ACTN3 R577X (rs1815739), BDKRB2 -9/+9 (rs5810761), and AGT Met235Thr (rs699) genes are associated with athletic performance, but their relevance in handball remains unclear. Therefore, this study aimed to investigate the association of these polymorphisms with physical performance in Brazilian junior handball players. The study included 91 junior male handball players (16.4 +/- 0.7 years) and 74 age-matched non-athletes. Genotypes for ACTN3 (R577X), BDKRB2 (-9/+9), and AGT (M235T) were identified using PCR-based techniques. Physical tests assessed upper limb strength (medicine ball throw) and lower limb strength (standing long jump). Genotypic and allelic frequencies were compared using Chi-square tests, while performance data were analyzed using ANOVA and t-tests (p <= 0.05). No significant differences were found in genotypic or allelic frequencies between athletes and controls for ACTN3 (R577X), BDKRB2 (-9/+9), and AGT (M235T) polymorphisms. Among athletes, ACTN3 RR carriers displayed significantly better upper limb strength (p = 0.049, d = 0.48). However, no genotype significantly influenced lower limb strength or anthropometric traits. Additionally, the study found no significant associations between BDKRB2 and AGT polymorphisms and physical performance parameters. This study demonstrates that specific genetic variants of the ACTN3 (R577X) gene may influence individual traits, such as upper-body strength, in Brazilian junior handball players. However, we found limited influence of BDKRB2 (-9/+9), and AGT (M235T) polymorphisms on overall performance. This lack of association may be attributed to the small sample size and the genetic heterogeneity of the studied population, encouraging further research with larger cohorts.