ACTN3 Research Articles

Genetic polymorphisms and bruxism: A scoping review

BackgroundRecent studies have highlighted the multifactorial nature of bruxism, with behavioral, psychosocial, and physiological factors, including genetic predisposition, contributing to its development. However, the role of genetic markers in determining susceptibility to bruxism remains poorly understood, with limited studies offering significant findings. ObjectivesTo identify the current knowledge to investigate the susceptibility of genetic markers for sleep (SB) and/or awake bruxism (AB). Materials and methodsSeven electronic databases and two grey literature platforms were searched up to January 2024. We included studies that related different types of genes and/or genetic polymorphisms with different types of bruxism, regardless of age or sex of the participants. To be included the study must have described the form of detection of bruxism. ResultsA total of 21 reports were included. Of these, 16 were primary research reports. The remaining five articles consisted of four systematic reviews and a literature review incorporating a systematic mapping process, and network visualization. Within the pool of 16 primary study reports, seven focused on the association of genetic polymorphisms with both SB and AB, while seven concentrated solely on the association with SB. One primary study reported results related to probable AB and one article did not specify the bruxism type. Regarding all the studied genes and polymorphisms, significant association results were obtained for 15 polymorphisms from 11 different genes. Self-reported SB was associated with genes from the serotonergic (5HTR2A) and dopaminergic pathways (DRD2, DRD3, and ANKK1), as well as genes encoding enzymes (COMT and MMP9) and proteins (ACTN3 and ANKK1). Instrumentally reported SB was linked only to the reverse telomerase gene (TERT). Self-reported AB was associated with the ACTN3 and ANKK1 genes. ConclusionThis review identified 30 genes and 56 polymorphisms variations potentially associated with either SB or AB. However, few presented significant results regarding positive associations, mostly acting at neurotransmitter pathways. The authors recommend further studies to determine the susceptibility of genetic markers as a risk factor for bruxism.

Association of alpha-actinin-3 genotype with muscle mass and physical function in community-dwelling older adults.

Polymorphisms (rs1815739; R577X) in the gene encoding alpha-actinin-3 (ACTN3) are thought to be associated with body composition and physical function in older people and athletes. RR homozygotes are associated with greater expression of ACTN3 protein in muscle than the X-allele carriers. We aimed to investigate the association between ACTN3 R577X polymorphism and appendicular skeletal muscle mass, walking speed, and muscle strength in older adults. A cross-sectional analysis was performed on 265 community-dwelling older adults (mean age 74.0 ± 5.8years, 63.4% female) who provided data on ACTN3 gene polymorphisms and completed surveys in the Tarumizu study conducted between 2018 and 2019. Genetic polymorphisms were categorized as RR homozygous and X allele. Muscle mass was assessed using the appendicular skeletal muscle mass index (ASMI), and physical function was assessed based on walking speed and relative muscle strength. Those in the bottom 25% for each sex were considered "low" and the association with ACTN3 genotype was examined. Considering ACTN3 polymorphism, 72 participants were RR homozygotes (27.2%) and 193 were X-allele carriers (72.8%). After adjusting for potential confounders, RR homozygosity was associated with not having low muscle mass (odds ratio 0.39, 95% confidence interval 0.19-0.82, p = 0.013) but not with low walking speed and muscle strength. The association between ACTN3 genotype and physical function in community-dwelling older adults is not clear; however, it is considered to be associated with muscle mass.

The ACTN3 p.Arg577Ter Genetic Variants Biomarker of the Fitness Performance, in Oaxaca Amerindian Population

Backgrond. ACTN3 is primarily expressed in fast skeletal muscle fibres. A common nonsense polymorphism in this gene is ACTN3 R577X (rs1815739:C>T) results in replacement of an arginine (R) with a premature stop codon (X) at amino acid 577 in the fast muscle protein α-actinin-3, which causes an absolute deficiency of α-actinin-3 protein and alterations in muscle metabolism. A common null polymorphism in the ACTN3 gene The ACTN3 p.Arg577Ter allele (p.R577* or R577X) has undergone positive selection, with an increase in the X allele frequency as modern humans migrated out of Africa into the colder, less species-rich Eurasian climates Aim. Analized the frequency of allele or genotypes from ACTN3 p.Arg577Ter genetic variants biomarker of the fitness performance, in Oaxaca Amerindian population. Methods. From people of different ethnic groups the State of Oaxaca, DNA was extracted from peripheral blood to extract DNA using the geneKatcher kit (invitrogene), to amplify the polymorphism p.Arg577Ter was realized by qRT_PCR, using tqman probes by determined by allelic discrimination. Results. The more frequency allele is wild type R in all populations, more tan 50%. The Genotype more prevalent is heterocygote RX. In afromexican population Genotype XX o ter-X/ter-X is a allelic variant. Distribution allelic and genotype is verry heterogenus in the populations. In conclusión the ACTN3 R577X gene variant can be used as a clinical marker for the selection of sports talents in the state of Oaxaca, considering that it has already been validated at the population level, with the R allele being more frequent in the state, which is the one associated with a greater selective advantage in sports that require muscular strength and greater physical performance.

Increased prevalence of the null allele of the p.Arg577Ter variant in the ACTN3 gene in Brazilian long-distance athletes: A retrospective study.

The phenotypic consequences of the p.Arg577Ter variant in the α-actinin-3 (ACTN3) gene are suggestive of a trade-off between performance traits for speed and endurance sports. Although there is a consistent association of the c.1729C allele (aka R allele) with strength/power traits, there is still a debate on whether the null allele (c.1729T allele; aka X allele) influences endurance performance. The present study aimed to test the association of the ACTN3 p.Arg577Ter variant with long-distance endurance athlete status, using previously published data with the Brazilian population. Genotypic data from 203 long-distance athletes and 1724 controls were analysed in a case-control approach. The frequency of the X allele was significantly higher in long-distance athletes than in the control group (51.5% vs. 41.4%; p=0.000095). The R/X and X/X genotypes were overrepresented in the athlete group. Individuals with the R/X genotype instead of the R/R genotype had a 1.6 increase in the odds of being a long-distance athlete (p=0.012), whereas individuals with the X/X genotype instead of the R/R genotype had a 2.2 increase in the odds of being a long-distance athlete (p=0.00017). The X allele, mainly the X/X genotype, was associated with long-distance athlete status in Brazilians.

Differences in ACTN3 Genotype in Professional Ssireum Players Between Weight Classes and Elite/Non-Elite Status

PURPOSE This study aimed to identify ACTN3 gene polymorphisms amongprofessional ssireum players by weight class and between elite and non-elite players,and to select genotype that matches the characteristics of the sport. METHODS The subjects of this study were 148 male athletes currently working as professionalssireum players. Chi-square test cross-tabulation analysis was conducted to examinethe differences in ACTN3 genotypes between weight classes and between elite andnon-elite players. RESULTS There were no significant differences in allele or genotypebetween ssireum players, but there were significant differences in R-allele and XXgenotype. CONCLUSIONS Players with the R-allele type of the ACTN3 gene weremore often classified as elite. Using this marker as a basis for organizing a playerselection and training programs would be more effective in training those that matchthe characteristics of elite players of the game.

Evaluating the Influence of the ACTN3 rs1815739 Gene Polymorphism on the Performance of Physically Active Adult Males in the Arrowhead Agility Drill Test

The alpha actinin-3 gene (ACTN3) is a significant candidate gene among genetic markers that determine athletic ability. The ACTN3 gene is responsible for the creation of the actin protein in fast-twitch muscle fibers, which is associated with muscle power and speed. The objective of this study was to analyze the changes in performance of the arrowhead agility drill test and the distribution of genotype variants in the ACTN3 rs1815739 gene polymorphism in physically active adult males after a 6- week training period. The research will focus on a cohort of 58 male students, aged 19-24, who are enrolled in the Faculty of Sports Sciences and participate in swimming activities. Genomic DNA was extracted from swab samples obtained from participants using the Buccalyse DNA Extraction Kit from Isohelix, following the manufacturer's supplied technique. The study findings revealed that there was no statistically significant difference between all three genotypes when comparing the pre-test and post-test values of the sample group in terms of left and right foot characteristics. Within this framework, it is acknowledged that the outcomes derived from our investigation could potentially influence the research findings. These aspects include the restricted sample size and the incapacity to regulate individual variances such as concentration and motivation during the pre-test and post-test sessions. Nevertheless, it is believed that the results obtained from our study could potentially enhance future research and literary works in the same field.

The roles of ACE I/D and ACTN3 R577X gene variants in heat acclimation

Roles of genes in heat acclimation (HA, repeated exercise-heat exposures) had not been explored. ACE I/D and ACTN3 R577X genetic polymorphisms are closely associated with outstanding exercise performances. This study investigated whether the two polymorphisms influenced the response to HA. Fifty young Han nationality male subjects were selected and conducted HA for 2 weeks. Exercise indicators (5-km run, push-up and 100-m run) were tested and rest aural thermometry (RTau) was measured before and after HA. ACE gene was grouped by I homozygote and D carrier, and ACTN3 gene was grouped by R homozygote and X carrier. Results showed that there were no differences between groups in age, body mass index, exercise indicators and RTau before HA. After HA, RTau of ACE I homozygote was lower than that of D carrier [F(1, 48) = 9.12, p = 0.004, η = 0.40]. Compared with RTau before HA, that of I homozygote decreased after HA (Δ = −0.26 °C, 95 % CI -0.34–0.18, p < 0.001), while that of D carrier did not change. There was a ACE gene × HA interaction in RTau [F(1, 48) = 14.26, p < 0.001, η = 0.48]. No effect of ACTN3 gene on RTau was observed. For exercise indicators, there were no differences between groups after HA, and no gene × HA interactions were observed. There may be a strong interaction of ACE gene and HA in the change of rest core temperature. I homozygote may have an advantage on improving heat tolerance.

Which Polymorphism Is The Distinguishing Factor For Fitness Athletes: The Ace Indel or Actn3 rs1815739?

Purpose: The purpose of this research is to investigate the occurrence of ACE I/D and ACTN3 rs1815739 variations in sub-elite fitness athletes and to determine which gene is distinctive by comparing genotype and allele frequencies with sedentary individuals. Material and Methods: 41 sub-elite fitness athletes and 41 sedentary volunteers participated in the study. Genetic analyzes of the athletes were determined using molecular-based methods such as DNA isolation using a commercial kit, Real-time polymerase chain reaction (Real-Time PCR), and Polymerase chain reaction (PCR) after blood collection in EDTA tubes. The Chi-Square test was used to compare the genotype distribution and I, D, C, and T allele frequencies of ACE I/D and ACTN3 rs1815739 polymorphisms for statistical significance. Results: Analysis of data from our study revealed no statistically significant differences in ACE I/D polymorphisms between groups (p=0.4438), but statistically significant differences in ACTN3 rs1815739 polymorphisms significant difference (p=0.0313). Conclusion: In conclusion, in our study, it can be said that the ACTN3 gene is a distinguishing factor in fitness.

Exploring the nexus between sports performance and genetics: a comprehensive literature review.

Sport is a multifactorial phenomenon that is influenced by many factors. Although many factors affect sports performance, genetic factors may be important issues that need to be examined. In addition, the relationship between sports performance and genes is still unclear. Due to the developments in omics technologies, approximately 185 genetic markers have been identified for the relationship between sports performance and genes. These genes are expressed differently in metabolism according to the characteristics of sports performance. The aim of this study was to investigate the relationship between sports and genetics. Pubmed, Pubmed Central and Google Scholar internet search engines were used in current study. Additionally, the PRISMA technique was used in the study design. For this purpose, COL1A1, COL5A1, ACTN3 and ELN genes may be important regulators on soft tissues. For endurance sports, genes like ACE, ACTN3, ADRB2, HFE, COL5A1, BDKRB2, NOS3, HIF, VEGF, AMPD and PPARGC1A significantly may influence performance limits. ACE and ACTN3 genes, on the other hand, may determine power/strength and speed skills in athletes. As a result, knowing the athlete's genetic predisposition to sports can be effective in achieving success.

Meta-analysis of genomic variants in power and endurance sports to decode the impact of genomics on athletic performance and success.

Association between genomic variants and athletic performance has seen a high degree of controversy, as there is often conflicting data as far as the association of genomic variants with endurance, speed and strength is concerned. Here, findings from a thorough meta-analysis from 4228 articles exploring the association of genomic variants with athletic performance in power and endurance sports are summarized, aiming to confirm or overrule the association of genetic variants with athletic performance of all types. From the 4228 articles, only 107 were eligible for further analysis, including 37 different genes. From these, there were 21 articles for the ACE gene, 29 articles for the ACTN3 gene and 8 articles for both the ACE and ACTN3 genes, including 54,382 subjects in total, from which 11,501 were endurance and power athletes and 42,881 control subjects. These data show that there is no statistically significant association between genomic variants and athletic performance either for endurance or power sports, underlying the fact that it is highly risky and even unethical to make such genetic testing services for athletic performance available to the general public. Overall, a strict regulatory monitoring should be exercised by health and other legislative authorities to protect the public from such services from an emerging discipline that still lacks the necessary scientific evidence and subsequent regulatory approval.

Sprint and Anaerobic Power with the Soccer-Specific ACTN3 Gene: A Distintive Example

Sprint and Anaerobic Power with the Soccer-Specific ACTN3 Gene: A Distintive Example

Interaction between Habitual Green Tea and Coffee Consumption and ACTN3 Genotype in Association with Skeletal Muscle Mass and Strength in Middle-Aged and Older Adults

BackgroundRecent studies have suggested the potential benefits of habitual coffee and green tea consumption on skeletal muscle health. However, it remains unclear whether these benefits are modified by genetic factors, particularly the alpha-actinin-3 (ACTN3) genotype, which is associated with the skeletal muscle phenotype. This study aimed to investigate the interaction between habitual coffee or green tea consumption and the ACTN3 genotype in association with skeletal muscle mass (SMM) and strength.MethodsThis cross-sectional study was conducted on 1,023 Japanese middle-aged and older adults (619 females, aged 45–74 years) living in the community. SMM was gauged using a bioelectrical impedance spectroscopy device, and handgrip strength (HGS) was used to measure muscle strength. The ACTN3 genotype (RR, RX, and XX) was determined from blood samples. Sex-specific linear regression models were used to analyze the interactions between coffee or green tea consumption and the ACTN3 genotype in association with SMM and HGS.ResultsIn females, a significant interaction was observed between green tea consumption and the ACTN3 genotype in association with HGS (P interaction < 0.05). Furthermore, stratified analysis revealed a positive association between green tea consumption and HGS, specifically in females with the ACTN3 XX genotype (P trend < 0.05). In males, no significant interactions were observed between coffee or green tea consumption and the ACTN3 genotype in association with SMM or HGS (P interaction > 0.05).ConclusionOur findings suggest that the skeletal muscle strength benefits associated with habitual green tea consumption may be contingent upon sex and the ACTN3 genotype.

Genes Associated with Muscle, Tendon and Ligament Injury Epidemiology in Women’s Amateur Football Players

Background: There is a lack of specific genetic studies regarding injuries in women’s football. However, different genetic factors have been associated with tendon/ligament injuries in women football players. The aim of the study was to examine the genotypic frequencies of genes associated with injury risk and epidemiology in women’s amateur football players and the aetiology of injuries. Methods: In total, 168 women’s amateur football players from football clubs in the Spanish second division league and Caucasian descent were enrolled in this prospective observational cross-sectional study. AMPD1 (rs17602729), ACE (rs4646994), ACTN3 (rs1815739), CKM (rs8111989) and MLCK (rs2849757 and rs2700352) polymorphisms were genotyped. The characteristics of 169 non-contact injuries during the 2022/2023 season were classified following the International Olympic Committee (IOC) Consensus Statement for reporting injuries as follows: musculoskeletal, tendon/ligament, injury setting; and severity. The disequilibria of polymorphisms were estimated using the Hardy–Weinberg Equilibrium (HWE). The characteristics of the injuries were recorded, and the genotype characteristics were analysed. The genotype frequencies of all polymorphisms were compared between non-injured and injured football players and injury aetiologies. Results: The AMPD1 genotype distribution differed between tendon/ligament injured and non-injured (p = 0.003) with a higher frequency in the TT genotype and T allele. The genotype distribution was different for the CKM and MLCK c.37885C&gt;A polymorphisms in training and match injuries (p = 0.038 and p = 0.031, respectively). In the ACTN3 and AMPD1 polymorphisms, the distribution of the TT genotype in both genes showed a higher frequency in severe injuries (all p &lt; 0.001). Conclusions: Tendon/ligament injury epidemiology in women’s amateur football players was associated especially with the TT genotype of the AMPD1 gene. The TT genotype of the AMPD1 and ACTN3 genes was also associated with severity, and the CKM and MLCK polymorphisms were associated with injury settings.

Computational Prediction of deleterious mutation in ACTN3 gene in cattle

Computational Prediction of deleterious mutation in ACTN3 gene in cattle

Acute responses of strength-related gene expressions to maximum strength and force sense acuity.

Although high muscle strength worsens the sense of force, it is unknown whether there is a relationship between this deterioration and the underlying molecular mechanisms. This study examined the relationship between decreased force sense (FS) acuity and strength-related gene expressions. Maximal voluntary isometric contraction (MVIC) and FS (50% MVIC) tests were performed on the knee joints of twenty-two subjects. The expression analyses were evaluated by qRT-PCR in blood samples taken before, after MVIC, after 50% MVIC, and 15 min after the test. MVIC and FS error values were significantly correlated with each other (r = .659, p = .001). The qRT-PCR analyses demonstrated that the expressed mRNAs of the interleukin 6 (IL-6), alpha-actinin 3 (ACTN3), angiotensin-converting enzyme (ACE), brain-derived neurotrophic factor (BDNF), and ciliary neurotrophic factor receptor (CNTFR) genes dramatically increased until 50% MVIC and subsequently decreased 15 min after the exercise (p < .05). The muscle-specific creatine kinase (CKMM), myosin light chain kinase (MLCK), and G-protein β3 subunit (GNB3) genes reached their peak expression levels 30 min after MVIC (p < .05). ACE and ACTN3 gene expression increased significantly in parallel with the increased FS error (p < .05). These gene expression fluctuations observed at 50% MVIC and after the rest could be related to changes in cellular metabolism leading to fatigue. The time points of gene expression levels during exercise need to be considered. The force acuity of those whose maximal force develops too much may deteriorate.

المظاهر الوراثية لجين ACTN3 / EXON-19 وارتباطها بأداء خيول الثيربرد في العراق

The research was conducted in the Iraqi Equestrian Club (15 km west of Baghdad city center) for the period from 10/1/2021 to 11/30/2022, with the aim of revealing the ACTN3 gene/ EXON-19 region polymorphism and its relationship to the performance of Thoroughbred horses. British in Iraq. It was found that there are 3 variants (3 SNPs) in the ACTN3 gene with respect to exon 19 and in different sites , which are rs1143578253, their polymorphism are TT, TA, and AA and their distribution ratios were 15.38, 56.41 and 28.21%, and that the non-significant difference, and the frequency of the allele was 0.44 and 0.56 for the two alleles C and T, respectively, and the heterogeneity rs1141508235. It appeared that there were two genotypes of the studied piece in the ACTN3/ EXON19 gene in the thoroughbred horses, CC and CT genotype, with the absence of the TT structure, and the highly significant differences (P≤0.01) between the distribution ratios of the combinations in the British thoroughbred, as the two ratios were 87.18 and 12.82% for the two genotypes CC and TC, and the allelic frequencies for the C and T alleles were 0.94 and 0.06, respectively. The distribution percentages of ACTN3/EXON19 gene polymorphism at position rs1146645613/SNP for the horse sample in this study had high significant differences (P≤0.01) between the genotype's distribution percentages in the British thoroughbred, and the percentages were 87.18 and 12.82% for the two genotypes TT and TC, and the mutant structure did not appear. CC and the frequencies for the T and C alleles were 0.94 and 0.06, respectively. There was a significant variation (P≤0.05) in the depth of respiration after exercise according to the different polymorphism of the rs1143578253 hetero, and the highest rate was for the TT combination (84.80 ± 5.13 seconds) as well as the number of respiration times after exercise, but for the hybrid genotype TA (59.16 ± 1.81 times/min), there was There was a highly significant variation (P≤0.01) in the rate of speed according to the genotype of the thoroughbred horses, and the highest rate of speed was for horses with the mutant genotype AA and the lowest for their counterparts with the wild genotype TT. It is concluded from the study that the ACTN3 gene has a distinct role in some of the traits studied on British terrier horses in Iraq, especially the number and depth of respiration after exercise, rate of speed, and some body measurements, specifically body length, chest circumference, and frontal height, as it varied significantly with the difference in the polymorphism of some variations.

Principal components analysis to evaluate complex association of polymorphisms in ACE and ACTN3 genes and the extent of cardiovascular adaptive changes in elite athletes.

Present article aims at clarifying the association of ACE and ACTN3 polymorphisms with adaptive heart changes in elite athletes from power, endurance and mixed sport disciplines using the principal component analysis (PCA). Overall, 281 elite male athletes are divided into three groups: strength-type sports, endurance and mixed sports. After anthropometric measurements, physical and ultrasound examination of the heart, the athletes were exposed to a physical load test. All groups were analyzed for functional ACE and ACTN3 polymorphisms. In order to convert a set of examined, possibly correlated adaptive cardiovascular changes into a set of values of linearly uncorrelated variables we used principal component analysis (PCA). The type of sport significantly affects not only the athlete's anthropometric characteristics, but also on the scope and specificity of the investigated adaptive cardiovascular changes. Athletes from the mixed group of sports showed the best working efficiency of the heart. PCA showed that the type of sport, but not genetic predisposition affects the co-adaptation of complex traits. Effect of genotype, type of sport and their interaction on observed variability in morpho-functional cardiovascular adaptive changes in elite athletes can be used for a better understanding of the clinical phenomenon of athlete's heart and sudden cardiac death syndrome.

Genetic and Physiological Predictors of Bioenergetic Adaptation Skeletal Muscles in Athletes of Cyclic Sports

When performing maximum loads, an important criterion for assessing prospects is the achievement of the best result with the least metabolic changes in the body of athletes, which indicates the possibility of further increasing physical performance. The study of the mechanisms of energy supply and the reaction of body systems when testing performance under special conditions is one of the important conditions for the development of additional biochemical criteria for assessing the prospects of athletes. Purpose: To study genetic and physiological predictors of bioenergetic adaptation of skeletal muscles in athletes of cyclic sports. Methods: 76 athletes of cyclic sports (speed skating, running disciplines in track-and-field) of European origin who lived in the Southern Urals region took part in the study. The average age of the study participants was 22.1 ± 2.5 y.o. Experience in sports was at least 5 years. We used the Step One Real-Time PCR System (Applied Biosystems, USA) device for real-time polymerase chain reaction. The study of bio-energetic indicators of athletes' physical performance was carried out using the bicycle ergometry method (test with maximum load). Biochemical studies were carried out using a Lactate Scout Plus lactometer. Results: Significant differences were found in the ΔLa (%) indicator: in athletes with a dominant homozygous genotype R/R, lactate clearance during a 10-minute rest after performing a bicycle ergometer load is statistically significantly higher than in athletes with a recessive homozygous genotype X/X (20.14±12.74%, versus 11.11±3.12%; p&lt;0.05). The major allele C (R) was associated with moderate and high lactate clearance (OR = 2.25 [95% CI: 0.99 – 5.11] and OR = 2.24 [95% CI: 0.91 – 5.51], respectively). At the same time, a statistically significant association was identified between the minor allele T(X) and the homozygous genotype TT (XX) with low lactate clearance (OR = 12.14 [95% CI: 1.30 – 13.55]). High values of lactate clearance indicate the utilization of lactate from peripheral blood and more efficient recovery processes in carriers of the major allele C (R). Conclusions: lactate clearance during a 10-minute rest period after a bicycle ergometer test with maximum load and DNA profiling of the ACTN3 gene rs1815739 can be recommended as significant physiological and genetic predictors of bioenergetic adaptation of skeletal muscles in cyclical sports athletes of Caucasian origin in the Southern Urals.

The Distinguishing Factor in Soccer Players is Aerobic Performance, not the ACTN3 Gene

The Distinguishing Factor in Soccer Players is Aerobic Performance, not the ACTN3 Gene

Association of the ACTN3 Gene's Single-Nucleotide Variant Rs1815739 (R577X) with Sports Qualification and Competitive Distance in Caucasian Athletes of the Southern Urals.

To study the associations of SNV rs1815739 (C577T or R577X) allelic variants and genotypes of the ACTN3 gene with qualification and competitive distance in Caucasian athletes of the Southern Urals. A total of 126 people of European origin who lived in the Southern Urals region took part in this study. The first group included 76 cyclical sports athletes (speed skating, running disciplines in track-and-field): SD (short distances) subgroup-40 sprinters (mean 22.1 ± 2.4 y.o.); LD (long distances) subgroup-36 stayer athletes (mean 22.6 ± 2.7 y.o.). The control group consisted of 50 healthy nonathletes (mean 21.4 ± 2.7 y.o.). We used the Step One Real-Time PCR System (Applied Biosystems, USA) device for real-time polymerase chain reaction. The frequency of the major allele R was significantly higher in the SD subgroup compared to the control subgroup (80% vs. 64%; p-value = 0.04). However, we did not find any significant differences in the frequency of the R allele between the athletes of the SD subgroup and the LD subgroup (80% vs. 59.7%, respectively; p-value > 0.05). The frequency of the X allele was lower in the SD subgroup compared to the LD subgroup (20% vs. 40.3%; p-value = 0.03). The frequency of homozygous genotype RR was higher in the SD subgroup compared to the control group (60.0% vs. 34%; p-value = 0.04). The R allele was associated with competitive distance in the SD group athletes compared to those of the control group (OR = 2.45 (95% CI: 1.02-5.87)). The X allele was associated with competitive distance in the LD subgroup compared to the SD subgroup (OR = 2.7 (95% CI: 1.09-6.68)). Multiplicative and additive inheritance models demonstrated that high athletic performance for sprinters was associated with the homozygous dominant genotype 577RR in cyclical sports athletes of Caucasian origin in the Southern Urals.