The anxiety level of an athlete is important. The serotonin transporter protein is encoded by the SLC6A4 gene. Serotonin is one of the most important members of anxiety metabolism. Serotonin transporter protein plays a role in bringing serotonin back from the synaptic space to the presynaptic neuron. We aimed to determine the genotype and allele distributions of the SLC6A4 promoter L/S polymorphism in football players and compare it with the control group. For this purpose, 20 football players participated in our study. Genotyping was performed by PCR after DNAs were isolated from buccal epithelial cells. When we examined the genotype distributions, the LL, LS and SS were found as 4 (20%), 8 (40%) and 8 (40%), respectively. In the control group, the same genotype number and percentages were determined as 10 (23%), 25 (57%) and 9 (20%), respectively. In terms of genotype distribution, no statistically significant significance was found between the two groups (p = 0.2493). When allelic distributions were examined in the athlete group, the L allele was counted as 16 (40%) and the S allele as 24 (60%). In the control group, the L allele 45 (51%) and the S allele were counted as 43 (49%). When the two groups were compared statistically in terms of allelic distribution, no statistically significant difference was found (p = 0.2423). As a result, LS and SS genotype were co-dominant and at the same time higher than LL genotype. At the same time, when we compared the S allele with the L allele, it was found that the S allele was more in percentage. Studies have found that the S allele is associated with anxiety. Sports psychologist can support athletes with S allele who are prone to anxiety problems. This is the first study to report that S allele is more common than L allele in Turkish football players.

One of the most important members of serotonin metabolism is serotonin transporter (5HTT), which takes the serotonin back from the synaptic cavity into the presynaptic neuron (reuptake). This protein is encoded by the SLC6A4 gene and the functional deletion / insertion mutation in the promoter region of this gene affects the transcription rate. The “S” allele is referred to be the short form of the gene and studies in this field reported its relationship with anxiety. In the present study, we aimed to determine the distribution of the short (S) and long (L) alleles of SLC6A4 gene in 44 young, successful and healthy Turkish male soccer players. Genotyping process was completed by conventional polymerase chain reaction (PCR) after DNA isolation. According to the results, 10 (23%) of the players had LL, 25 (57%) had LS and 9 (20%) had SS genotypes. In the allele distributions, L allele was counted as 45 (51%) and S allel as 43 (49%). It has been reported that SLC6A4 alleles show large variation in individuals with neuropsychiatric disorders compared to the healthy individuals. This is the first study to report that LL genotype and L allele are more frequent than SS genotype and S allele in Turkish young professional soccer players

Studies to date have shown the contribution of an athletes’ genetic endowment in athletic performance. Although these studies revealed that cognitive abilities influence athletes’ competitive performance, there are only a few studies trying to investigate the association between genetic polymorphisms, which is associated with cognitive ability, and athletic performance. In the present study, we aimed investigate the link between dopamine receptor-2 (DRD2) gene rs1800497 polymorphism, which is known to exert influences on brain dopaminergic system and athletic performance of volleyball players and bodybuilders. In this regard, we enrolled 9 female volleyball players and 15 active bodybuilders in the study. Real-time PCR methodology was used for genotyping. The respective numbers and percentages of A1A1, A1A2 and A2A2 genotypes in bodybuilders were 2 (13%), 1 (7%) and 12 (80%). All the volleyball players had A2A2 genotypes. The results have revealed that addiction related A1 allele is underrepresented in volleyball players and bodybuilders. These first findings indicate that the polygenic or multifactorial mechanism may explain effect of cognitive abilities in athletes’ performance.