The ACTN3 R577X Polymorphism across Three Groups of Elite Male European Athletes

The ACTN3 R577X polymorphism (rs1815739) is a strong candidate to influence elite athletic performance. Yet, controversy exists in the literature owing to between-studies differences in the ethnic background and sample size of the cohorts, the latter being usually low, which makes comparisons difficult. In this case:control genetic study we determined the association between elite athletic status and the ACTN3 R577X polymorphism within three cohorts of European Caucasian men, i.e. Spanish, Polish and Russian [633 cases (278 elite endurance and 355 power athletes), and 808 non-athletic controls]. The odds ratio (OR) of a power athlete harbouring the XX versus the RR genotype compared with sedentary controls was 0.54 [95% confidence interval (CI): 0.34–0.48; P = 0.006]. We also observed that the OR of an endurance athlete having the XX versus the RR genotype compared with power athletes was 1.88 (95%CI: 1.07–3.31; P = 0.028). In endurance athletes, the OR of a “world-class” competitor having the XX genotype versus the RR+RX genotype was 3.74 (95%CI: 1.08–12.94; P = 0.038) compared with those of a lower (“national”) competition level. No association (P>0.1) was noted between the ACTN3 R577X polymorphism and competition level (world-class versus national-level) in power athletes. Our data provide comprehensive support for the influence of the ACTN3 R577X polymorphism on elite athletic performance.     

Assessment of association of ACTN3 genetic polymorphism with Korean elite athletic performance

Genetic and environmental factors have long been suspected to influence on physical performance and athletic ability. Recent studies have suggested that the skeletal-muscle actin binding protein α-actinin-3 (ACTN3) gene was associated with athletic performance in Europeans. It would lead us to hypothesize that ACTN3 gene may be one of the factors that influence certain variation in muscle function, but origins and replicate tests remain to be elucidated. We analyzed ACTN3 genetic polymorphism to assess the possible role of the genotype differences (RR, RX, and XX) in elite athletic performance in a population-based case-control study in Korea. The ACTN3 gene locus was found to be no deviation from Hardy–Weinberg expectation. We observed a significant association between female sprint/power athletes (SPAs) and control (P = 0.028), that of male SPAs or all SPA samples did not. The female SPAs appeared to have a dearth of 577 XX genotype (OR 0.104, 95 % CI 0.013–0.822, P = 0.011) compared with the control with a replicating finding in the Korean population. Thus, our results imply that the sex specific ACTN3 R577X genotype may provide a significant effect on elite Korean female SPAs status, although larger sample sizes and functional studies are necessary to further elucidate these findings.     

ACTN3 genotype is associated with human elite athletic performance

There is increasing evidence for strong genetic influences on athletic performance and for an evolutionary "trade-off" between performance traits for speed and endurance activities. We have recently demonstrated that the skeletal-muscle actin-binding protein alpha-actinin-3 is absent in 18% of healthy white individuals because of homozygosity for a common stop-codon polymorphism in the ACTN3 gene, R577X. alpha-Actinin-3 is specifically expressed in fast-twitch myofibers responsible for generating force at high velocity. The absence of a disease phenotype secondary to alpha-actinin-3 deficiency is likely due to compensation by the homologous protein, alpha-actinin-2. However, the high degree of evolutionary conservation of ACTN3 suggests function(s) independent of ACTN2. Here, we demonstrate highly significant associations between ACTN3 genotype and athletic performance. Both male and female elite sprint athletes have significantly higher frequencies of the 577R allele than do controls. This suggests that the presence of alpha-actinin-3 has a beneficial effect on the function of skeletal muscle in generating forceful contractions at high velocity, and provides an evolutionary advantage because of increased sprint performance. There is also a genotype effect in female sprint and endurance athletes, with higher than expected numbers of 577RX heterozygotes among sprint athletes and lower than expected numbers among endurance athletes. The lack of a similar effect in males suggests that the ACTN3 genotype affects athletic performance differently in males and females. The differential effects in sprint and endurance athletes suggests that the R577X polymorphism may have been maintained in the human population by balancing natural selection.     

ACTN3 genotype is associated with increases in muscle strength in response to resistance training in women.

The alpha-actinin 3 (ACTN3) gene encodes a protein of the Z disk of myofibers, and a polymorphism of ACTN3 results in complete loss of the protein. The ACTN3 genotype (R577X) has been found to be associated with performance in Australian elite athletes (Yang N, MacArthur DG, Gulbin JP, Hahn AG, Beggs AH, Easteal S, and North K. Am J Hum Genet 73: 627-631, 2003). We studied associations between ACTN3 genotype and muscle size [cross-sectional area of the biceps brachii via magnetic resonance imaging (MRI)] and elbow flexor isometric (MVC) and dynamic [1-repetition maximum (1-RM)] strength in a large group of men (N = 247) and women (N = 355) enrolled in a 12-wk standardized elbow flexor/extensor resistance training program of the nondominant arm at one of eight study centers. We found no association between ACTN3 R577X genotype and muscle phenotype in men. However, women homozygous for the ACTN3 577X allele (XX) had lower baseline MVC compared with heterozygotes (P < 0.05) when adjusted for body mass and age. Women homozygous for the mutant allele (577X) demonstrated greater absolute and relative 1-RM gains compared with the homozygous wild type (RR) after resistance training when adjusted for body mass and age (P < 0.05). There was a trend for a dose-response with genotype such that gains were greatest for XX and least for RR. Significant associations were validated in at least one ethnic subpopulation (Caucasians, Asians) and were independent of training volume. About 2% of baseline MVC and of 1-RM strength gain after training were attributable to ACTN3 genotype (likelihood-ratio test P value, P = 0.01), suggesting that ACTN3 is one of many genes contributing to genetic variation in muscle performance and adaptation to exercise.     

The Association of Sport Performance with ACE and ACTN3 Genetic Polymorphisms: A Systematic Review and Meta-Analysis

Background

Genetic polymorphism is suggested to be associated with human physical performance. The angiotensin I-converting enzyme insertion/deletion (ACE I/D) polymorphism and the α-actinin-3 gene (ACTN3) R577X polymorphism have been most widely studied for such association analysis. However, the findings are frequently heterogeneous. We aim to summarize the associations of ACE I/D and ACTN3 R577X with sport performance by means of meta-analysis.

Methods

We systematically reviewed and quantitatively summarized published studies, until October 31, 2012, on relationship between ACE/ACTN3 genetic polymorphisms and sports performance, respectively.

Results

A total of 366 articles on ACE and 88 articles on ACTN3 were achieved by literature search. A significant association was found for ACE II genotype compared to D allele carriage (DD+ID) with increased possibility of physical performance (OR, 1.23; 95% CI, 1.05–1.45). With respect to sport discipline, the II genotype was found to be associated with performance in endurance athletes (OR, 1.35; 95% CI, 1.17–1.55). On the other hand, no significant association was observed for ACTN3 RR genotype as compared to X allele carriage (XX+RX) (OR, 1.03; 95% CI, 0.92–1.15). However, when restricted the analyses to power events, a significant association was observed (OR, 1.21; 95% CI, 1.03–1.42).

Conclusion

Our results provide more solid evidence for the associations between ACE II genotype and endurance events and between ACTN3 R allele and power events. The findings suggest that the genetic profiles might influence human physical performance.     

The evolution of skeletal muscle performance: gene duplication and divergence of human sarcomeric α‐actinins

In humans, there are two skeletal muscle α‐actinins, encoded by ACTN2 and ACTN3, and the ACTN3 genotype is associated with human athletic performance. Remarkably, approximately 1 billion people worldwide are deficient in α‐actinin‐3 due to the common ACTN3 R577X polymorphism. The α‐actinins are an ancient family of actin‐binding proteins with structural, signalling and metabolic functions. The skeletal muscle α‐actinins diverged ～250–300 million years ago, and ACTN3 has since developed restricted expression in fast muscle fibres. Despite ACTN2 and ACTN3 retaining considerable sequence similarity, it is likely that following duplication there was a divergence in function explaining why α‐actinin‐2 cannot completely compensate for the absence of α‐actinin‐3. This paper focuses on the role of skeletal muscle α‐actinins, and how possible changes in functions between these duplicates fit in the context of gene duplication paradigms.     

ACTN3 GENOTYPE IS ASSOCIATED WITH TESTOSTERONE LEVELS OF ATHLETES

α-Actinin-3 (ACTN3) has been proposed to regulate skeletal muscle differentiation and hypertrophy through its interaction with the signalling protein calcineurin. Since the inhibition of calcineurin potentiates the production of testosterone, we hypothesized that α-actinin-3 deficiency (predicted from the ACTN3 XX genotype) may influence serum levels of testosterone of athletes. Objective: To investigate the association of ACTN3 gene R577X polymorphism with resting testosterone levels in athletes. Methods: A total of 209 elite Russian athletes from different sports (119 males, 90 females) were genotyped for ACTN3 gene R577X polymorphism by real-time PCR. Resting testosterone was examined in serum of athletes using enzyme immunoassay. Results: The mean testosterone levels were significantly higher in both males and females with the ACTN3 R allele than in XX homozygotes (males: RR: 24.9 (5.7), RX: 21.8 (5.5), XX: 18.6 (4.9) ng · mL^-1, P = 0.0071; females: RR: 1.43 (0.6), RX: 1.21 (0.71), XX: 0.79 (0.66) ng · mL^-1, P = 0.0167). Conclusions: We found that the ACTN3 R allele was associated with high levels of testosterone in athletes, and this may explain, in part, the association between the ACTN3 RR genotype, skeletal muscle hypertrophy and power athlete status.     

The ACTN3 R577X Polymorphism Is Associated with Cardiometabolic Fitness in Healthy Young Adults

Homozygosity for a premature stop codon (X) in the ACTN3 “sprinter” gene is common in humans despite the fact that it reduces muscle size, strength and power. Because of the close relationship between skeletal muscle function and cardiometabolic health we examined the influence of ACTN3 R577X polymorphism over cardiovascular and metabolic characteristics of young adults (n = 98 males, n = 102 females; 23 ± 4.2 years) from our Assessing Inherent Markers for Metabolic syndrome in the Young (AIMMY) study. Both males and females with the RR vs XX genotype achieved higher mean VO₂ peak scores (47.8 ± 1.5 vs 43.2 ±1.8 ml/O₂/min, p = 0.002) and exhibited higher resting systolic (115 ± 2 vs 105 ± mmHg, p = 0.027) and diastolic (69 ± 3 vs 59 ± 3 mmHg, p = 0.005) blood pressure suggesting a role for ACTN3 in the maintenance of vascular tone. We subsequently identified the expression of alpha-actinin 3 protein in pulmonary artery smooth muscle, which may explain the genotype-specific differences in cardiovascular adaptation to acute exercise. In addition, we utilized targeted serum metabolomics to distinguish between RR and XX genotypes, suggesting an additional role for the ACTN3 R577X polymorphism in human metabolism. Taken together, these results identify significant cardiometabolic effects associated with possessing one or more functional copies of the ACTN3 gene.     

Are ‘Endurance’ Alleles ‘Survival’ Alleles? Insights from the ACTN3 R577X Polymorphism

Exercise phenotypes have played a key role for ensuring survival over human evolution. We speculated that some genetic variants that influence exercise phenotypes could be associated with exceptional survival (i.e. reaching ≥100years of age). Owing to its effects on muscle structure/function, a potential candidate is the Arg(R)577Ter(X) polymorphism (rs1815739) in ACTN3, the structural gene encoding the skeletal muscle protein α-actinin-3. We compared the ACTN3 R577X genotype/allele frequencies between the following groups of ethnically-matched (Spanish) individuals: centenarians (cases, n = 64; 57 female; age range: 100–108 years), young healthy controls (n = 283, 67 females, 216 males; 21±2 years), and humans who are at the two end-points of exercise capacity phenotypes, i.e. muscle endurance (50 male professional road cyclists) and muscle power (63 male jumpers/sprinters). Although there were no differences in genotype/allele frequencies between centenarians (RR:28.8%; RX:47.5%; XX:23.7%), and controls (RR:31.8%; RX:49.8%; XX:18.4%) or endurance athletes (RR:28.0%; RX:46%; XX:26.0%), we observed a significantly higher frequency of the X allele (P = 0.019) and XX genotype (P = 0.011) in centenarians compared with power athletes (RR:47.6%; RX:36.5%;XX:15.9%). Notably, the frequency of the null XX (α-actinin-3 deficient) genotype in centenarians was the highest ever reported in non-athletic Caucasian populations. In conclusion, despite there were no significant differences with the younger, control population, overall the ACTN3 genotype of centenarians resembles that of world-class elite endurance athletes and differs from that of elite power athletes. Our preliminary data would suggest a certain ‘survival’ advantage brought about by α-actinin-3 deficiency and the ‘endurance’/oxidative muscle phenotype that is commonly associated with this condition.     

Altered Ca2+ Kinetics Associated with α-Actinin-3 Deficiency May Explain Positive Selection for ACTN3 Null Allele in Human Evolution

Over 1.5 billion people lack the skeletal muscle fast-twitch fibre protein α-actinin-3 due to homozygosity for a common null polymorphism (R577X) in the ACTN3 gene. α-Actinin-3 deficiency is detrimental to sprint performance in elite athletes and beneficial to endurance activities. In the human genome, it is very difficult to find single-gene loss-of-function variants that bear signatures of positive selection, yet intriguingly, the ACTN3 null variant has undergone strong positive selection during recent evolution, appearing to provide a survival advantage where food resources are scarce and climate is cold. We have previously demonstrated that α-actinin-3 deficiency in the Actn3 KO mouse results in a shift in fast-twitch fibres towards oxidative metabolism, which would be more “energy efficient” in famine, and beneficial to endurance performance. Prolonged exposure to cold can also induce changes in skeletal muscle similar to those observed with endurance training, and changes in Ca²⁺ handling by the sarcoplasmic reticulum (SR) are a key factor underlying these adaptations. On this basis, we explored the effects of α-actinin-3 deficiency on Ca²⁺ kinetics in single flexor digitorum brevis muscle fibres from Actn3 KO mice, using the Ca²⁺-sensitive dye fura-2. Compared to wild-type, fibres of Actn3 KO mice showed: (i) an increased rate of decay of the twitch transient; (ii) a fourfold increase in the rate of SR Ca²⁺ leak; (iii) a threefold increase in the rate of SR Ca²⁺ pumping; and (iv) enhanced maintenance of tetanic Ca²⁺ during fatigue. The SR Ca²⁺ pump, SERCA1, and the Ca²⁺-binding proteins, calsequestrin and sarcalumenin, showed markedly increased expression in muscles of KO mice. Together, these changes in Ca²⁺ handling in the absence of α-actinin-3 are consistent with cold acclimatisation and thermogenesis, and offer an additional explanation for the positive selection of the ACTN3 577X null allele in populations living in cold environments during recent evolution.     

Speed and power-related gene polymorphisms associated with playing position in elite soccer players

Heritability studies on sport-related traits accepted that endurance, speed, power, and strength abilities include an active genetic predisposition to elite soccer participation. This study evaluates the influence of selected genetic variants on performance in speed, power, and strength laboratory tests on a group of elite soccer players, including their playing position. A ninety-nine male elite soccer players were compared to controls (n = 107) and tested for quadriceps and hamstrings isokinetic strength at speed 60°/s, 180°/s, and 300°/s, jump performance, and genotypes of ACTN3 (R577X, rs1815739), ACE (I/D, rs1799752), NOS3 (Glu298Asp, rs1799983), AMPD1 (34C/T, rs17602729), UCP2 (Ala55Val, rs660339), BDKRB2 (+9/-9, rs5810761) and IL1RN (VNTR 86-bp). The ACTN3 XX homozygotes in defenders had lower quadriceps and hamstring isokinetic strength in all tested speeds than ACTN3 RX and RR genotypes (p < 0.05). The ACTN3 RR homozygotes in defenders had higher quadriceps strength in all tested velocities than the RX heterozygotes (p < 0.05). We also found other associations between playing-position in soccer and increased strength of lower limbs for AMPD1 CC and NOS3 Glu/Glu genotypes, and IL1RN*2 allele carriers. Total genetic score regression explained 26% of the variance in jump performance and isokinetic strength. The ACTN3 R allele, NOS3 Glu/Glu genotypes, and IL1RN*2 allele pre-disposed the attackers and defenders playing position in elite soccer, where those positions have higher strength and power measures than midfielders. Midfielders have lower strength and power conditions than other playing positions without relation to strength and power genes.     

Genomic analysis reveals association of specific SNPs with athletic performance and susceptibility to injuries in professional soccer players

The development of specific and individualized training programs is a possible way to improve athletic performance and minimize injuries in professional athletes. The information regarding the sport's physical demands and the athletes’ physical profile have been, so far, considered as exhaustive for the design of effective training programs. However, it is currently emerging that the genetic profile has to be also taken into consideration. By merging medical and genetic data, it is thus possible to identify the athlete's specific attitude to respond to training, diet, and physical stress. In this context, we performed a study in which 30 professional soccer players, subjected to standard sport medical evaluation and practices, were also screened for genetic polymorphism in five key genes (ACTN3, COL5A1, MCT1, VEGF, and HFE). This genetic analysis represents the central point of a multidisciplinary method that can be adopted by elite soccer teams to obtain an improvement in athletic performance and a concomitant reduction of injuries by tailoring training and nutritional programs. The genetic fingerprinting of single athletes led to the identification of two performance-enhancing polymorphisms (ACTN3 18705C>T, VEGF-634C>G) significantly enriched. Moreover, we derived a genetic model based on the gene set analyzed, which was tentatively used to reduce athletes’ predisposition to injuries, by dictating a personalized nutrition and training program. The potential usefulness of this approach is concordant with data showing that this team has been classified as the healthiest and least injured team in Europe while covering the highest distance/match with the highest number of high-intensity actions/match.     

A gene for speed? The evolution and function of α‐actinin‐3

The alpha-actinins are an ancient family of actin-binding proteins that play structural and regulatory roles in cytoskeletal organisation and muscle contraction. alpha-actinin-3 is the most-highly specialised of the four mammalian alpha-actinins, with its expression restricted largely to fast glycolytic fibres in skeletal muscle. Intriguingly, a significant proportion ( approximately 18%) of the human population is totally deficient in alpha-actinin-3 due to homozygosity for a premature stop codon polymorphism (R577X) in the ACTN3 gene. Recent work in our laboratory has revealed a strong association between R577X genotype and performance in a variety of athletic endeavours. We are currently exploring the function and evolutionary history of the ACTN3 gene and other alpha-actinin family members. The alpha-actinin family provides a fascinating case study in molecular evolution, illustrating phenomena such as functional redundancy in duplicate genes, the evolution of protein function, and the action of natural selection during recent human evolution.     

Physiological variables and mitochondrial-related genotypes of an athlete who excels in both short and long-distance running

We report the athletic, physiological and mitochondrial-related genomic data of an Israeli endurance runner. He is holding the Israeli record in 10,000, 5000, 1500 and 800 m run, along with being one of the best Israeli 400 m runners. We tested the ACTN3 R577X, and six polymorphisms in the PPARGC1A-NRF-TFAM pathway genes. The case athlete was heterozygous for the ACTN3 R577X variation and had five out of six ‘endurance-oriented’ genotypes, scoring significantly high in endurance ‘optimal’ genotype profile. In conclusion, we suggest that the case athlete is favoured by polygenic profile that is more suitable for mitochondrial biogenesis, regardless of his good phenotypic accomplishments in short-term running events.     

Gene variants related to the power performance of the Lithuanian athletes

ACE (I/D), ACTN3 (R/X), PPARGC1A (Gly482Ser) and PPARA (G/C) polymorphisms have been linked to the success in power-oriented sports through the intermediate phenotypes. The study involved 193 Lithuanian elite athletes and 250 controls. The measured phenotypic variables included short-term explosive muscle power (STEMP) and anaerobic alactic maximum power (AAMP). ACE DD genotype was more common among endurance athletes compared to the power athletes. The ACTN3 genotype frequencies of the elite athletes differed from those of non-elite athletes; however, there were no differences among the athletes and the control group across the PPARGC1A Gly482Ser genotypes. The frequency of PPARA CC genotype increased with the growing skill level of athletes (non-elite 2%, sub-elite 7.7%, elite 11.6%). The STEMP and AAMP were higher in the males than females and they were also higher in the power-oriented group compared to the endurance sports group. Success in power sports can be attributed to the ACE II, PPARGC1A SerSer, PPARA CC genotype in association with phenotypic characteristics such as AAMP and STEMP. ACTN3 XX genotype may not be critical but rather additive to endurance performance. The results show that high muscle power depends on both environmental and genetic factors.     

ACTN3 Gene R577X Polymorphism Associated with High-Density Lipoprotein Cholesterol and Adiponectin in Rugby Players

Objective: To determine the relationship between the R577X polymorphism of the α-actinin-3 (ACTN3), which may play a role in the individual differences observed in the effects of exercise on health benefits and antiatherogenic markers (i.e., high-density lipoprotein cholesterol [HDL-C] and adiponectin) in athletes.Methods: Seventy-six male rugby players (mean age 19.8 years) were enrolled in this study. Genomic DNA was extracted from peripheral blood samples, and restriction fragment length polymorphism-polymerase chain reactions were conducted to assess ACTN3 genotypes. Body mass index (BMI), waist circumference, serum lipids including HDL-C, and adiponectin levels were measured. Current smoking and alcohol intake habits were evaluated with a questionnaire. All of the parameters were compared between 2 groups displaying frequently observed genotypes: one group consisting of patients having either the R/R or R/X genotype and a second group with the X/X genotype.Results: The frequency of the X allele was 0.55 and the distribution of the genotypes was 35.5% (n = 27) for X/X, 39.5% (n = 30) for R/X, and 25.0% (n = 19) for R/R. Serum HDL-C and adiponectin levels were significantly higher in X/X genotype compared to the R/R or R/X genotype (HDL-C 1.6 ± 0.3 [SD] vs. 1.4 ± 0.2 mmol/L; P<.01, adiponectin 8.8 ± 2.6 vs. 6.9 ± 2.3 μg/mL; P<.01), even after adjustments for confounders (P<.01).Conclusion: There may be a relationship between the ACTN3 genotype and HDL-C and adiponectin levels in rugby players. This may be useful information when determining the individual responses of antiatherogenic markers to exercise.Abbreviations:ACTN3 = α-actinin-3BMI = body mass indexCVD = cardiovascular diseaseHDL-C = high-density lipoprotein cholesterolLDL-C = low-density lipoprotein cholesterolR = arginine (R) at amino acid position 577 of the ACTN3 proteinTC = total cholesterolTG = triglycerideX = truncation at amino acid position 577 of the ACTN3 protein     

Genetic basis of elite combat sports athletes: a systematic review

Each athlete’s innate talent is widely recognized as one of the important contributors to achievement in athletic performance, and genetic factors determine a significant portion of talent or traits. Advances in DNA sequencing technology allow us to discover specific genetic variants contributing to these traits in sports performance. The objective of this systematic review is to identify genes that may play a significant role in the performance of elite-level combat sports athletes. Through the review of 18 full-text articles, a total of 109 different polymorphisms were investigated in 14,313 participants (2,786 combat sports athletes, 8,969 non-athlete controls, 2,558 other sports athletes). Thirteen polymorphisms showed a significant difference between elite combat athletes and the control group, and consist of 8 (PPARA rs4253778, ACTN3 rs1815739, ACE rs4646994, CKM rs8111989, MCT1 rs1049434, FTO rs9939609, GABPβ1 rs7181866 and rs8031031) oriented to athletic performance and 5 (COMT rs4680, FEV rs860573, SLC6A2 rs2242446, HTR1B rs11568817, ADRA2A rs521674) focused on psychological traits including emotional and mental traits in combat sports athletes. In addition, a recent whole genome sequencing study identified 4 polymorphisms (KIF27 rs10125715, APC rs518013, TMEM229A rs7783359, LRRN3 rs80054135) associated with reaction time in wrestlers. However, it is not clearly identified which genes are linked explicitly with elite combat sports athletes and how they affect the elite athlete’s status or performance in combat sports. Hence, a greater number of candidate genes should be included in future studies to practically utilize the genetic information.     

Differing Evolutionary Histories of the ACTN3*R577X Polymorphism among the Major Human Geographic Groups

It has been proposed that the functional ACTN3*R577X polymorphism might have evolved due to selection in Eurasian human populations. To test this possibility we surveyed all available population-based data for this polymorphism and performed a comprehensive evolutionary analysis of its genetic diversity, in order to assess the action of adaptive and random mechanisms on its variation across human geographical distribution. The derived 577X allele increases in frequency with distance from Africa, reaching the highest frequencies on the American continent. Positive selection, detected by an extended haplotype homozygosisty test, was consistent only with the Eurasian data, but simulations with neutral models could not fully explain the results found in the American continent. It is possible that particularities of Native American population structure could be responsible for the observed allele frequencies, which would have resulted from a complex interaction between selective and random factors.     

Genetic associations of body composition,flexibility and injury risk with ACE,ACTN3 and COL5A1 polymorphisms in Korean ballerinas

[Purpose]

The purpose of this study was to exam the association of body composition, flexibility, and injury risk to genetic polymorphisms including ACE ID, ACTN3 RX, and COL5A1 polymorphisms in ballet dancers in Korea.

[Methods]

For the purpose of this study, elite ballerinas (n = 97) and normal female adults (n = 203) aged 18 to 39 were recruited and these participants were tested for body weight, height, body fat, fat free mass, flexibility, injury risks on the joints and gene polymorphisms (ACE, ACTN3, COL5A1 polymorphism).

[Results]

As results, the ACE DD genotype in ballerinas was associated with higher body fat and percentage of body fat than the ACE II and ID genotypes (p < 0.05). In the study on the ACTN3 polymorphism and ballerinas, the XX genotype in ballerinas had lower body weight and lower fat-free mass than the RR and RX genotype (p < 0.005). Also, the means of sit and reach test for flexibility was lower in the ACTN3 XX genotype of ballerinas than the RR and RX genotype of ballerinas (p < 0.05). Among the sports injuries, the ankle injury of the XX-genotyped ballerinas was in significantly more prevalence than the RR and XX-genotyped ballerinas (p < 0.05). According to the odd ratio analysis, XX-genotyped ballerinas have the injury risk on the ankle about 4.7 (95% CI: 1.6~13.4, p < 0.05) times more than the RR and RX-genotyped ballerinas. Meanwhile, the COL5A1 polymorphism in ballerinas has no association with any factors including flexibility and injury risks.

[Conclusion]

In conclusion, ACE polymorphism and ACTN3 polymorphism were associated with ballerinas'' performance capacity; COL5A1 was not associated with any factors of performance of Ballerinas. The results suggested that the ACE DD genotype is associated with high body fat, the ACTN3 XX genotype is associated with low fat-free mass, low flexibility, and higher risk of ankle-joint injury.