<b>Analysis of the Influence of </b><b><i>ACTN-3 </i></b><b>and </b><b><i>BDNF </i></b><b>Gene Variations</b><b>on the Performance of International-Level Athletics Athletes</b>

The purpose of the study is to investigate the genotype distribution and performance lev- 20 els according to genotypes of a-Actinin-3 (ACTN3) and brain-derived neurotrophic factor (BDNF) 21 gene polymorphisms, which are thought to be related to the athletic performance of international- 22 level athletics athletes. A total of 64 athletes, 33 women and 31 men, between the ages of 18-32, 23 voluntarily participated in the study. The athletes participating in the study were divided into four 24 groups. The first group consisted of sprint, throwing, and jumping (n = 17); the second group of 25 middle-distance (n = 15), the third group of long-distance (n = 13), and the fourth group of walking 26 athletes (n = 19). The International Association of Athletics Federations (IAAF) score was used to 27 determine the performance levels of the personal best (PB) participants. Oral swab samples were 28 taken to obtain DNA for genotyping that was performed by the real-time PCR method. The signifi- 29 cance level was determined as p < 0.05. Chi-square/Fisher’s exact test was used to compare the allele 30 frequencies within and between the groups and the study used an independent t-test to compare 31 differences between two genotypes and a one-way ANOVA to analyze differences among three 32 genotypes. The study investigated the PB scores of the athletes according to ACTN3 genotypes and 33 found no significant differences based on the genotype distribution (p > 0.05). Regarding the BDNF 34 gene polymorphism, the study did not find significant differences in middle-distance, long-dis- 35 tance, and walking groups (p > 0.05); however, a significant relationship was identified between 36 BDNF gene polymorphism and performance in sprint and power groups (p = 0.029). Accordingly, 37 the study may conclude that while ACTN3 gene polymorphism does not significantly relate to ath- 38 letic performance, BDNF gene variation shows a notable influence in sprinting, throwing, and jump- 39 ing activities, indicating its potential role in specific sports disciplines. This research could clarify 40 BDNF's association with sprint/throw/jump performance, leading to new methods in athletic train- 41 ing and enhancement.