ACTN3 R577X Genotype Research Articles

Association of ACTN3 R577X Genotype with Physical Fitness in Japanese Male College Students

Association of ACTN3 R577X Genotype with Physical Fitness in Japanese Male College Students

The Association between ACTN3 R577X Polymorphism and Range of Motion: A Systematic Review and Meta-analysis.

The R577X polymorphism in the α-actinin-3 gene (ACTN3) is associated with muscle strength and power; there is an association between ACTN3 R577X polymorphism and range of motion (ROM). We examined the effect of the ACTN3 R577X polymorphism on ROM through meta-analysis and systematic review. Relevant studies published before April 14, 2022 were identified from the PubMed database using the following keywords and Boolean operators: ("flexibility" or "Joint Range of Motion" or "Joint Flexibility" or "Range of motion") and ("ACTN3" or "alpha-actinin 3"). Studies that met the following criteria were included: (1) published in English, (2) included human subjects, (3) provided ROM measurements, and (4) analyzed the ACTN3 R577X genotype. A total of 2908 participants from seven studies were included in the meta-analysis. The additive genetic model was assessed using a meta-regression model, and dominant and recessive models were analyzed using a random effects model. The ROM in the XX+RX genotype was significantly higher than that in the RR genotype (recessive model: p<0.001), and it increased additively in the order XX>RX>RR (additive model: p=0.029). However, no significant association was observed in the dominant model. These findings further elucidate the association between flexibility and the ACTN3 R577X genotype.

Genotype Distribution of the ACTN3 p.R577X Polymorphism in Elite Badminton Players: A Preliminary Study.

α-Actinin-3 is a protein with a structural role at the sarcomeric Z-line in skeletal muscle. As it is only present in fast-type muscle fibers, α-actinin-3 is considered a key mechanical component to produce high-intensity muscle contractions and to withstand external tension applied to the skeletal muscle. α-Actinin-3 is encoded by the gene ACTN3, which has a single-nucleotide polymorphism (p.R577X; rs1815739) that affects the expression of α-actinin-3 due to the presence of a stop codon. Individuals homozygous for the 577R allele (i.e., RR genotype) and RX heterozygotes express functional α-actinin-3, while those homozygous for the 577X (i.e., XX genotype) express a non-functional protein. There is ample evidence to support the associations between the ACTN3 genotype and athletic performance, with higher frequencies of the 577R allele in elite and professional sprint and power athletes than in control populations. This suggests a beneficial influence of possessing functional α-actinin-3 to become an elite athlete in power-based disciplines. However, no previous investigation has determined the frequency of the ACTN3 genotypes in elite badminton players, despite this sport being characterized by high-intensity actions of intermittent nature such as changes of direction, accelerations, jumps and smashes. The purpose of this study was to analyze ACTN3 R577X genotype frequencies in professional badminton players to establish whether this polymorphism is associated with elite athlete status. A total of 53 European Caucasian professional badminton players competing in the 2018 European Badminton Championships volunteered to participate in the study. Thirty-one were men (26.2 ± 4.4 years) and twenty-two were women (23.4 ± 4.5 years). Chi-squared tests were used to analyze the differences in the distribution of ACTN3 genotypes (RR, RX and XX) between categories and sexes. The ACTN3 RR genotype was the most frequent in the sample of professional badminton players (RR = 49.1%, RX = 22.6% and XX = 28.3%). None of the badminton players ranked in the world's top ten possessed the XX genotype (RX = 60%, RR = 40%). The distribution of the ACTN3 genotypes was similar between male and female professional badminton players (men: RR = 45.2%, RX = 25.8% and XX = 29.0%; women: RR = 54.5%, RX = 18.2% and XX = 27.3%; χ2 = 0.58; p = 0.750). The distribution of the ACTN3 genotypes in badminton players was different from the 1000 genome database for the European population (χ2 = 15.5; p &lt; 0.001), with an overrepresentation of the RR genotype (p &lt; 0.05) and an underrepresentation of the RX genotype (p &lt; 0.01). In conclusion, the expression of functional α-actinin-3, associated with RR and RX genotypes in the ACTN3 gene may confer an advantage for reaching the status of elite athlete in badminton, and especially the world's top-ten ranking. Large-scale studies with different ethnic backgrounds are needed to confirm the association of the R allele of ACTN3 with badminton performance.

Association of the ACTN3 rs1815739 Polymorphism with Physical Performance and Injury Incidence in Professional Women Football Players.

The p.R577X polymorphism (rs1815739) in the ACTN3 gene causes individuals with the XX genotype to be deficient in functional α-actinin-3. Previous investigations have found that XX athletes are more prone to suffer non-contact muscle injuries, in comparison with RR and RX athletes who produce a functional α-actinin-3 in their fast-twitch fibers. This investigation aimed to determine the influence of the ACTN3 R577X polymorphism on physical performance and injury incidence of players competing in the women’s Spanish first division of football (soccer). Using a cross-sectional experiment, football-specific performance and epidemiology of non-contact football-related injuries were recorded in a group of 191 professional football players. ACTN3 R577X genotype was obtained for each player using genomic DNA samples obtained through buccal swabs. A battery of physical tests, including a countermovement jump, a 20 m sprint test, the sit-and-reach test and ankle dorsiflexion, were performed during the preseason. Injury incidence and characteristics of non-contact injuries were obtained according to the International Olympic Committee (IOC) statement for one season. From the study sample, 28.3% of players had the RR genotype, 52.9% had the RX genotype, and 18.8% had the XX genotype. Differences among genotypes were identified with one-way analysis of variance (numerical variables) or chi-square tests (categorical variables). Jump height (p = 0.087), sprint time (p = 0.210), sit-and-reach distance (p = 0.361), and dorsiflexion in the right (p = 0.550) and left ankle (p = 0.992) were similar in RR, RX, and XX football players. A total of 356 non-contact injuries were recorded in 144 football players while the remaining 47 did not sustain any non-contact injuries during the season. Injury incidence was 10.4 ± 8.6, 8.2 ± 5.7, and 8.9 ± 5.3 injuries per/1000 h of football exposure, without differences among genotypes (p = 0.222). Injury rates during training (from 3.6 ± 3.7 to 4.8 ± 2.1 injuries per/1000 h of training exposure, p = 0.100) and match (from 47.8 ± 9.5 to 54.1 ± 6.3 injuries per/1000 h of match exposure, p = 0.209) were also similar in RR, RX, and XX football players. The ACTN3 genotype did not affect the mode of onset, the time needed to return to play, the type of injury, or the distribution of body locations of the injuries. In summary, women football players with different genotypes of the p.R577X ACTN3 polymorphism had similar values of football-specific performance and injury incidence. From a practical perspective, the ACTN3 genotyping may not be useful to predict performance or injury incidence in professional women football players.

ACTN3 R577X variant: could it be a determinant of sports performance in elite athletes in a Turkish population?

ACTN3 gene, which encodes a-actinin-3 and actin-binding protein, has been found to be associated with strong athletic performance, especially among track and field athletes. Therefore, in this study, our aim was to compare the allelic and genotype frequencies of the ACTN3 R577X variant among elite athletes specialized in different branches, and nonathletic controls in Turkey. In the present study, 316 subjects, including 168 athletes and 148 sedentary controls were genotyped for the ACTN3 R577X variant. Genotyping was conducted by polymerase chain reaction (PCR) method. Additionally, we evaluated the groups by dividing them as females and males. There were 48 females and 120 males in the athletes group, and 43 females and 105 males in the control group. Genetic associations were evaluated by chi-squire test or Fisher's exact test. There was a significant difference between the athletes and controls in terms of the ACTN3 R577X variant. ACTN3 RR and XX genotypes increased in the controls compared to the athletes, while RX genotype was higher in the athletes than the controls (P = 0.030). Then we evaluated the groups by separating them as females and males. Genotype distribution of the ACTN3 R577X differed between the male athletes and the male controls (P = 0.046). ACTN3 R577X RX genotype increased in the male athletes compared to the male control (P = 0.046). But ACTN3 R577X genotype and allele distribution was not significant between female athletes and female control group (P>0.05). As far as we know, this study is the largest series examining the ACTN3 R577X variant in Turkish athletes. Our results support that the ACTN3 R577X variant has a heterozygous advantage in athletic performance in the Turkish population. However, epigenetic, gene-gene and gene-environment interactions affects athlete performance should not be forgotten.

Genetic profile of sports climbing athletes from three different ethnicities.

This study aimed to investigate the ACTN3 R577X, ACE I/D, CKM rs8111989, and TRHR rs7832552 genotypes in climbers and controls in three ethnicities. The study consisted of 258 climbers (Japanese, n = 100; Polish, n = 128; Russian, n = 30) and 1151 controls (Japanese: n = 332, Polish: n = 635, Russian: n = 184). Genotyping results were analyzed using the TaqMan approach in Japanese and Polish subjects and HumanOmni1-Quad Bead Chips in Russian subjects. There were no significant differences in ACTN3 R577X and ACE I/D polymorphism distribution between climbers and controls in any ethnic cohort or model. The frequencies of the C allele in the CKM polymorphism and the T allele in the TRHR polymorphism were higher in climbers than in controls only in the Russian cohort (p = 0.045 and p = 0.039, respectively). The results of the meta-analysis on three cohorts showed that the frequency of XX + RX genotypes in the ACTN3 R577X polymorphism was significantly higher in climbers than that in the controls (p = 0.01). The X allele of the ACTN3 R577X polymorphism was associated with sport climbing status, as assessed using a meta-analysis of climbers across three different ethnicities.

The ACTN3 R577Xgth in Korea national combat athletes

The aim of the present study is the investigation of the association between the ACTN3 genotype and the grip strength according to measurements in Korea National combats athletes. Fifty-six Korea National combats athletes (Judo and wrestling, male = 38, female = 18) and two hundred and twenty-one control group of normal populations (male = 135, female = 86) were recruited for the present study. The variables under examination were body composition, Wingate anaerobic test, and handgrip strength. Genotyping for the ACTN3 (rs 1815739) polymorphism was performed using the TaqMan approach. ACTN3 gene distribution of subjects was in the Hardy–Weinberg equilibrium (athletes: P = 0.175; control: P = 0.508). The relative power drop ( P = 0.041) differed significantly among the ACTN3 genotypes, and non-significant differences in peak power and average power. The relative left hand grip strength in male ( P = 0.004) differed significantly between the ACTN3 R allele. However, non-significant differences right hand grip strength in male and both hand grip strength in female. We found a positive relationship between the ACTN3 R577X genotypes and the relative left hand grip strength in male Korean National combat athletes. Our data indicate that the ACTN3 R allele (RR and RX genotypes) is associated with muscle strength output capacity. Le but de la présente étude est l’investigation de l’association entre le génotype ACTN3 et la force de préhension selon des mesures en Corée national combat des athlètes. Cinquante-six athlètes de combat nationaux de Corée (judo et lutte, hommes = 38, femmes = 18) et deux cent vingt et un groupes témoin de populations normales (hommes = 135, femmes = 86) ont été recrutés pour la présente étude. Les variables examinées étaient la composition corporelle, le test anaérobie Wingate et la force de la poignée. Le génotypage du polymorphisme ACTN3 (rs 1815739) a été réalisé en utilisant l’approche TaqMan. La distribution du gène ACTN3 des sujets était dans l’équilibre Hardy–Weinberg (athlètes : p = 0,175 ; contrôle : p = 0,508). La chute de puissance relative ( p = 0,041) différait significativement entre les génotypes ACTN3, et pas de différences significatives de puissance de crête et de puissance moyenne. La force de préhension relative de la main gauche chez l’homme ( p = 0,004) différait significativement entre l’allèle ACTN3 R. Cependant, il n’y a pas de différences significatives entre la force de préhension de la main droite chez l’homme et la force de préhension de la main chez la femme. Nous avons trouvé une relation positive entre les génotypes ACTN3 R577X et la force de préhension relative de la main gauche chez les athlètes masculins de combat national coréen. Nos données indiquent que l’allèle ACTN3 R (génotypes RR et RX) est associé à la capacité de sortie de force musculaire.

Muscular Strength and Quality of Life in Older Adults: The Role of ACTN3 R577X Polymorphism.

As longevity is increasing, the 65-year-old and older population is projected to increase in the next decades, as are the consequences of age-related muscle deterioration on the quality of life. The purpose of this study was to examine the associations of the ACTN3 R577X polymorphism with quality of life and muscular strength in an older Spanish population. In total, 281 older adults participated in this study. Anthropometric measurements, chronic diseases, prescribed medications, quality of life, hand grip strength, and physical activity and nutritional status data were collected. ACTN3 R577X genotyping was determined using Taqman probes. Multivariate regression analysis revealed in adjusted model that, in men, the ACTN3 R577X genotype was significantly associated with hand grip strength (HGS), regression coefficient (β) = 1.23, p = 0.008, dimension 1 of the five-dimension questionnaire EuroQoL (EQ-5D, mobility), (β) = −1.44, p = 0.006, and clinical group risk (CGR) category (β) = −1.38, p = 0.006. In women, a marginal association between the ACTN3 R577X genotype and the CGR category was observed, with a regression coefficient of (β) = −0.97, (p = 0.024). Our findings suggest that the ACTN3 R577X genotype may influence the decline in muscle strength and quality of life in older Spanish adult males.

Effect of ACTN3 R577X Genotype on Injury Epidemiology in Elite Endurance Runners.

The p.R577X polymorphism (rs1815739) in the ACTN3 gene causes individuals with the ACTN3 XX genotype to be deficient in functional α-actinin-3. Previous investigations have found that XX athletes are more prone to suffer non-contact muscle injuries. This investigation aimed to determine the influence of the ACTN3 R577X polymorphism in the injury epidemiology of elite endurance athletes. Using a cross-sectional experiment, the epidemiology of running-related injuries was recorded for one season in a group of 89 Spanish elite endurance runners. ACTN3 R577X genotype was obtained for each athlete using genomic DNA samples. From the study sample, 42.7% of athletes had the RR genotype, 39.3% had the RX genotype, and 18.0% had the XX genotype. A total of 96 injuries were recorded in 57 athletes. Injury incidence was higher in RR runners (3.2 injuries/1000 h of running) than in RX (2.0 injuries/1000 h) and XX (2.2 injuries/1000 h; p = 0.030) runners. RR runners had a higher proportion of injuries located in the Achilles tendon, RX runners had a higher proportion of injuries located in the knee, and XX runners had a higher proportion of injuries located in the groin (p = 0.025). The ACTN3 genotype did not affect the mode of onset, the severity, or the type of injury. The ACTN3 genotype slightly affected the injury epidemiology of elite endurance athletes with a higher injury rate in RR athletes and differences in injury location. However, elite ACTN3 XX endurance runners were not more prone to muscle-type injuries.

Is ACTN3 R577X Genotype Associated with a Preference in Type of Exercise Such as Sprint or Endurance?

The purpose of this study was to determine whether genotypes in the α-actinin-3 gene are associated with preferences in the type of exercise (sprint vs. endurance) in male college students. The study enrolled 64 healthy male students aged 18-21 years old, excluding elite athletes. DNA was extracted from the subjects’ hair samples to determine the genotypes of the α-actinin-3 gene, whereas a simple questionnaire was used to investigate preference in the type of exercise. In summary, 35.5% of subjects with the RR and RX types (R-allele group) preferred sprint, whereas 47.3% of subjects with the XX type preferred endurance. Furthermore, 53.3% of the R-allele group and 31.6% of the XX group preferred endurance and sprint, respectively. This implies that the inconsistency (or mismatch) between muscle functional properties, which are characterized by genotypes and preference in type of exercise, tends to be greater in the R-allele group than in the XX type. In conclusion, the genotypes of α-actinin-3 did not play a significant role in deciding the preference in type of exercise. It can also be suspected that the mismatch between muscle functional properties and exercise preference is influenced by the daily life of students who are not exposed to high-intensity exercise stimuli.

Association Between Muscle Stiffness And Esr1 Rs2234693, Rs9340799 And Actn3 R577x Polymorphisms In Collegiate Athletes

Previous studies have reported that distinct gene polymorphisms (e.g. ACTN3 R577X, ESR1 rs2234693, rs9340799) are associated with muscle stiffness, amongst which ESR1 rs2234693 and rs9340799 polymorphisms are also associated with instances of muscle injury. PURPOSE: To investigate the association between muscle stiffness and ESR1 rs2234693, rs9340799 and ACTN3 R577X polymorphisms in collegiate athletes. METHODS: In this study, 40 athletes (33 men and 7 women), who had undergone resistance training, were evaluated for the occurrence of muscle stiffness (hamstring: biceps femoris, semitendinosus, and semimembranosus) by ultrasound shear wave elastography. Additionally, ESR1 rs2234693, rs9340799 and ACTN3 R577X polymorphisms were analyzed using the TaqMan SNP Genotyping Assay. Comparisons of muscle stiffness between the genotypes were performed using one-way ANOVA. The Hardy-Weinberg equilibrium was determined for the ESR1 rs2234693, rs9340799 and ACTN3 R577X polymorphism using a Chi-square test. RESULTS: Genotype frequencies of the ESR1 rs2234693 (CC 13%, CT 55%, TT 33%), rs9340799 (GG 3%, GA 25%, AA 73%) and ACTN3 R577X (RR 18%, RX 64%, XX 18%) polymorphisms were consistent with the Hardy-Weinberg equilibrium (p=0.36, p=0.90, p=0.08, respectively). However, there was no significant difference in muscle stiffness between ESR1 rs2234693 and ACTN3 R577X genotypes. Further, the GG or GA genotype of ESR1 rs9340799 polymorphism tend to exhibit greater muscle stiffness of the hamstring muscles compared with the AA genotype in collegiate athletes (27.2 ± 7.0kPa vs. 22.4 ± 6.7kPa; p= 0.054). CONCLUSIONS: Our results suggested that ESR1 rs2234693, rs9340799 and ACTN3 R577X polymorphisms are not associated with muscle stiffness in collegiate athletes.

ACTN3 R577X polymorphism related to sarcopenia and physical fitness in active older women

Background As the population is getting older, physical activity promotion becomes a good strategy to increase quality of life in the elderly; but genetic condition also plays an important role. The purpose of this study was to examine the association of the ACTN3 R577X polymorphism with physical fitness and muscle mass in physically active older women. Methods A cross-sectional study was performed with two groups of older women who practiced physical exercise regularly. The first cohort comprised 164 women (age 69.7 ± 3.2 years) and the second cohort 131 women (age 78.5 ± 3.0 years). The main outcome measures were anthropometric measures with assessment of sarcopenia and sarcopenic obesity, self-reported physical activity EXERNET questionnaire (EEPAQ), evaluation of physical fitness (muscle strength and flexibility test), and ACTN3 genotyping. Results Women above 75 years old with allele R presented a higher risk of experiencing sarcopenia compared to ACTNR XX homozygous women (odds ratio 0.356, 95% confidence interval 0.139–0.915, p = 0.026). Furthermore, statistically significant differences were found in the chair stand test (p = 0.04), as well as in the sit and reach test (p = 0.01), with better results for women below 75 years old with the ACTN3 XX genotype. Conclusions Sarcopenia and physical fitness show differences based on the ACTN3 R577X genotype in active older women.

Influence of the ACTN3 R577X genotype on the injury epidemiology of marathon runners.

A common single nucleotide polymorphism in the ACTN3 gene might result in the complete deficiency of α-actinin-3 (i.e., XX genotype). It has been found that ACTN3 XX individuals have several traits related to lessened muscle performance. This study aimed to determine the influence, if any, of ACTN3 genotypes on injury incidence of marathoners during the year preceding to participating in a competitive marathon race. Using a cross-sectional experimental design, the type and conditions of sports injuries were documented for one year in a group of 139 marathoners. Injuries were recorded following a consensus statement on injuries in Athletics. Afterward, ACTN3 genotyping was performed, and injury epidemiology was compared among RR, RX, and XX genotypes. The distribution of the RR/RX/XX genotypes was 28.8/42.8/23.5%, respectively. A total of 67 injuries were recorded. The frequency of marathoners that reported any injury during the previous year was not different across the genotypes (55.0/38.8/40.6%, P = 0.241). Although the overall injury incidence was not different among genotypes (2.78/1.65/1.94 injuries/1000 h of running, P = 0.084), the likelihood of suffering an injury was higher in RR than in RX (OR = 1.93: 95%CI = 0.87–4.30), and higher than in XX (OR = 1.79: 0.70–4.58). There was no difference in the conditions, severity, body location, time of year, or leading cause of injury among genotypes. However, XX presented a higher frequency of sudden-onset injuries (P = 0.024), and the OR for muscle-type injuries was 2.0 (0.51–7.79) times higher compared to RR runners. Although XX marathoners did not have a higher overall incidence of injury, the OR in these runners for muscle-type injuries was superior to RR and RX runners. The likelihood of suffering a muscle injury, especially with a sudden-onset, was twice in XX than in RR endurance runners.

Distribution of allele frequencies for genes associated with physical activity and/or physical capacity in a homogenous Norwegian cohort- a cross-sectional study

BackgroundThere are large individual differences in physical activity (PA) behavior as well as trainability of physical capacity. Heritability studies have shown that genes may have as much impact on exercise participation behavior as environmental factors. Genes that favor both trainability and participation may increase the levels of PA. The present study aimed to assess the allele frequencies in genes associated with PA and/or physical capacity, and to see if there is any association between these polymorphisms and self-reported PA levels in a cohort of middle-aged Norwegians of Scandinavian descent (n = 831; mean age mean age (± SD) 55.5 ± 3.8 years).ResultsThe genotype distributions of the ACTN3 R577X, ACE I/D and MAOA uVNTR polymorphisms were similar to other populations of European descent. When comparing the genotype distribution between the low/medium level PA group (LMPA) and high level PA groups (HPA), a significant difference in ACTN3 577X allele distribution was found. The X allele frequency was 10% lower in the HPA level group (P = 0.006). There were no differences in the genotype distribution of the ACE I/D or MAOA uVNTR polymorphism. Education and previous participation in sports or outdoor activities was positively associated with the self-reported PA levels (P ≤ 0.001).ConclusionsTo the best of our knowledge, this is the first study to report association between ACTN3 R577X genotype and PA level in middle-aged Scandinavians. Nevertheless, the contribution of a single polymorphism to a complex trait, like PA level, is likely small. Socioeconomic variables, as education and previous participation in sports or outdoor activities, are positively associated with the self-reported PA levels.

ACTN3 R577X Genotype in Professional and Amateur Tennis Players.

Moreno-Pérez, V, Machar, R, Sanz-Rivas, D, and Del Coso, J. ACTN3 R577X genotype in professional and amateur tennis players. J Strength Cond Res 34(4): 952-956, 2020-Several investigations have concluded that the RR genotype in the ACTN3 R577X polymorphism is overrepresented in elite athletes of strength- and power-based sports when compared with nonelite populations, suggesting a positive role of this genotype on physical performance. However, no investigation has been geared to determine the distribution of this polymorphism in elite tennis players. The aim of this study was to compare the frequency distribution of the ACTN3 R577X genotype in professional and nonprofessional tennis players to determine whether this polymorphism has an association with tennis performance. A total of 128 tennis players volunteered to participate in this study. From the total, 56 were professional tennis players (16 were top 10 in Women Tennis Association/Association of Tennis Professionals [WTA/ATP] rankings, 22 were top 100 in WTA/ATP rankings, and 18 were ranked > top 100 in the WTA/ATP rankings), and the remaining 72 were categorized as nonprofessional. Chi-squared tests were used to assess differences in the distribution of RR, RX, and XX genotypes between the different performance categories. The distribution of the RR, RX, and XX genotypes was similar in professional (33.9, 48.2, and 17.9%) and nonprofessional tennis players (37.5, 40.3, and 22.2%; p = 0.650). Furthermore, the distribution of the ACTN3 R577X polymorphism was not different in top 10 (25.0, 50.0, and 25.0%), top 100 (31.8, 50.0, and 18.2%), and WTA/ATP-ranked players (44.4, 44.4, and 11.2%; p = 0.847). These results indicate that the distribution of the ACTN3 R577X genotype is similar in tennis players of very different performance levels. This outcome suggests that the ACTN3 genotype was not associated with elite tennis performance.

PPARD CC and ACTN3 RR genotype prevalence among elite soccer players

ABSTRACTObjectives: Soccer is a complex sport in which players are required to perform variety of aerobic and anaerobic activities. The purpose of the study was to explore aerobic (PPARD CC) and anaerobic (ACTN3 RR) performance-related genotype frequencies among young soccer players and compare to those of sprinters/jumpers (S/J), long distance runners (LDR) and controls.Methods: Genomic DNA was extracted from buccal epithelial cells of 170 national level athletes (60 soccer players, 51 S/J, 59 LDR) and 51 non-athletic controls . Genotypes were determined using Taqman allelic discrimination assay.Results: Soccer players had non-significant lower frequency (15%) of the PPARD 294CC genotype compared to LDR (19%), but higher compared to S/J (10%). ACTN3 R577X genotype and allele frequencies of soccer players (28%) were not significantly different from those of S/J (39%)and LDR athletes (20%).Conclusions: Soccer players do not have a noticeable or clear genotype tendency compared to S/J and LDR. This may suggest that soccer players rely more on diverse physiological qualities as well as other factors that are required in the game, rather than on a single physiological attribute. It should be also noticed that the different physiological demands for diverse positional roles in soccer may contribute to the results’ heterogeneity.

ACTN3 R577X Genotype and Exercise Phenotypes in Recreational Marathon Runners.

Background: Homozygosity for the X-allele in the ACTN3 R577X (rs1815739) polymorphism results in the complete absence of α-actinin-3 in sarcomeres of fast-type muscle fibers. In elite athletes, the ACTN3 XX genotype has been related to inferior performance in speed and power-oriented sports; however, its influence on exercise phenotypes in recreational athletes has received less attention. We sought to determine the influence of ACTN3 genotypes on common exercise phenotypes in recreational marathon runners. Methods: A total of 136 marathoners (116 men and 20 women) were subjected to laboratory testing that included measurements of body composition, isometric muscle force, muscle flexibility, ankle dorsiflexion, and the energy cost of running. ACTN3 genotyping was performed using TaqMan probes. Results: 37 runners (27.2%) had the RR genotype, 67 (49.3%) were RX and 32 (23.5%) were XX. There was a difference in body fat percentage between RR and XX genotype groups (15.7 ± 5.8 vs. 18.8 ± 5.5%; effect size, ES, = 0.5 ± 0.4, p = 0.024), whereas the distance obtained in the sit-and-reach-test was likely lower in the RX than in the XX group (15.3 ± 7.8 vs. 18.4 ± 9.9 cm; ES = 0.4 ± 0.4, p = 0.046). Maximal dorsiflexion during the weight-bearing lunge test was different in the RR and XX groups (54.8 ± 5.8 vs. 57.7 ± 5.1 degree; ES = 0.5 ± 0.5, p = 0.044). Maximal isometric force was higher in the RR than in the XX group (16.7 ± 4.7 vs. 14.7 ± 4.0 N/kg; ES = −0.5 ± 0.3, p = 0.038). There was no difference in the energy cost of running between genotypes (~4.8 J/kg/min for all three groups, ES ~0.2 ± 0.4). Conclusions: The ACTN3 genotype might influence several exercise phenotypes in recreational marathoners. Deficiency in α-actinin-3 might be accompanied by higher body fatness, lower muscle strength and higher muscle flexibility and range of motion. Although there is not yet a scientific rationale for the use of commercial genetic tests to predict sports performance, recreational marathon runners who have performed such types of testing and have the ACTN3 XX genotype might perhaps benefit from personalized strength training to improve their performance more than their counterparts with other ACTN3 genotypes.

ACTN3 R577X Genotype Is Associated with ACTN3 Protein Expression Levels and Myosin Heavy Chain Composition in Japanese College-Level Male Sprinters

ACTN3 R577X Genotype Is Associated with ACTN3 Protein Expression Levels and Myosin Heavy Chain Composition in Japanese College-Level Male Sprinters

ACTN3 R577X Polymorphism Is Associated With the Incidence and Severity of Injuries in Professional Football Players.

The ACTN3 R577X gene variant results in the absence of the α-actinin-3 protein in ∼18% of humans worldwide and has been associated with athletic performance and increased susceptibility to eccentric muscle damage. The aim of this study was to investigate the association between ACTN3 R577X variant and indirect muscle disorders/injuries in professional football players. A case-control, genotype-phenotype association study. Two hundred fifty-seven male professional Italian football players (from Serie A, Primavera, Allievi, and Giovanissimi; age = 21.2 ± 5.3 years) and 265 nonathletic controls were recruited for the study. Genomic DNA was extracted using a buccal swab, and the ACTN3 R577X genotype was performed using a PCR method. Structural-mechanical injuries and functional muscle disorders were collected from a subgroup of 169 football players during the period of 2009 to 2014. We hypothesized that the 577XX genotype would be associated with higher predisposition to muscle injuries (compared with the other genotypes). ACTN3 XX (α-actinin-3 deficiency) players had 2.66 higher odds for an injury incidence than their ACTN3 RR counterparts (95% confidence interval [CI]: 1.09-6.63, P = 0.02), whereas RX and RR players had similar injury incidence. Furthermore, ACTN3 XX players had 2.13 higher odds for having a severe injury compared with their RR counterparts (95% CI: 1.25-3.74, P = 0.0054), whereas RX individuals had 1.63 higher odds for having a severe injury compared with the RR players (95% CI: 1.10-2.40, P = 0.015). The ACTN3 R577X polymorphism is associated with the incidence and severity of muscle injuries in professional football players; players with the ACTN3 577XX genotype have higher odds of having muscle injuries than their RR counterparts. Discovering the complex relationship between gene variants and muscle injuries may assist coaches, physiologists, and the medical community to development tailored injury prevention program for football players, which could provide a new edge for successful competition.

Is evolutionary loss our gain? The role of ACTN3 p.Arg577Ter (R577X) genotype in athletic performance, ageing, and disease.

A common null polymorphism in the ACTN3 gene (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. The ACTN3 p.Arg577Ter allele (aka 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 suggesting that the absence of α-actinin-3 may be beneficial in these conditions. Approximately 1.5 billion people worldwide are completely deficient in α-actinin-3. While the absence of α-actinin-3 influences skeletal muscle function and metabolism this does not result in overt muscle disease. α-Actinin-3 deficiency (ACTN3 XX genotype) is constantly underrepresented in sprint/power performance athletes. However, recent findings from our group and others suggest that the ACTN3 R577X genotype plays a role beyond athletic performance with effects observed in ageing, bone health, and inherited muscle disorders such as McArdle disease and Duchenne muscle dystrophy. In this review, we provide an update on the current knowledge regarding the influence of ACTN3 R577X on skeletal muscle function and its potential biological and clinical implications. We also outline future research directions to explore the role of α-actinin-3 in healthy and diseased populations.