ACTN3 Genotype Research Articles

Gz+ tolerance, body composition and ACTN-3 genotype of f-15/16 pilots

Gz+ tolerance, body composition and ACTN-3 genotype of f-15/16 pilots

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.

The ACE and ACTN3 polymorphisms in female soccer athletes

ObjectsWe investigated the association of ACE I/D and ACTN3 R577X polymorphisms with the performance of Chinese elite female soccer athletes for the first time.Material and methodsThe genotype distributions of ACE I/D and ACTN3 R577X in the athlete group and the control group of Chinese females were evaluated via PCR and compared. VO2max value was tested as per standard protocol.ResultsRegarding the distribution of ACE polymorphisms, the genotype frequency was indifferent between the athletes (II 40 %, ID 46.7 %, DD 13.3 %) and the controls (II 42 %, ID 48 %, DD 10 %). No difference in the I/D allele frequency was observed between the athlete group and the control group. Regarding the distribution of ACTN3 polymorphisms, the genotype frequency was significantly different between the athletes (XX 0 %, XR 53.3 %, RR 46.7 %) and the controls (XX 16 %, XR 44 %, RR 40 %). The allele frequency was observed no different between the athlete and the control group. The ACE ID and ACTN3 RR genotype combination was associated with higher VO2max values among defenders than among other players. According to VO2max values,The ACE and ACTN3 genotype combinations (II/ID/DD + RR/XR) significantly differed between the athletes and the controls (p < 0.05).ConclusionThese results suggested that the Chinese elite female soccer athletes were more likely to harbor the I allele and the R allele and that the combination of ACE II/ID and ACTN3 RR/XR was a synergetic determinant of the athletic performance of females in soccer.

Effect of ACE (I/D) and ACTN-3 (R/X) Genotypes on some Factors of Physical Fitness and Performance of Motor Skills in 6-8-Year-Old Children

Effect of ACE (I/D) and ACTN-3 (R/X) Genotypes on some Factors of Physical Fitness and Performance of Motor Skills in 6-8-Year-Old Children

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.

Distribution of α-actinin-3 rs1815739 and angiotensin-1 converting enzyme InDel polymorphisms in Turkish bodybuilders.

The determination of the genetic profiles of successful athletes and the effects of these genetic parameters on athletic performance is gaining increasing interest. The majority of studies assessing the genetics of athletes usually analyse the most well-known genetic variations in athletes associated with the different specialties. The aim of the present study was to analyse the ACE InDel and ACTN3 rs1815739 polymorphisms in Turkish bodybuilders. A total of 11 male bodybuilders were recruited and genotyped for these polymorphisms. The respective percentage of the ACE II, ID and DD genotypes were 18, 73 and 9. For the ACTN3 genotype, the respective frequencies were 55 and 45 for the RX and RR genotypes. No XX genotype was detected. The allelic counts were 12 (55%) for I and 10 (45%) for the D alleles of ACE; and 12 (55%) and 10 (45%) for R and X alleles, respectively, for the ACTN3 genotype. Additionally, 5 athletes had ID + RX genotypes in terms of ACE InDel and ACTN3 rs1815739 polymorphisms, respectively. These results indicate the importance of endurance related alleles of ACE and ACTN3 in bodybuilders. The results of the present are in agreement with previous studies, highlighting a potential association between specific polymorphisms and the endurance-related nature of bodybuilders. Further studies with larger cohorts are required to understand the association between these polymorphisms and specific parameters performance in bodybuilders.

LATE BREAKING NEWS E-POSTER PRESENTATION: LBP 10 ACTN3 genotype influences skeletal muscle mass regulation and the response to dexamethasone

Homozygosity for the common ACTN3 null polymorphism (ACTN3 577X) results in α-actinin-3 deficiency in ∼20% of humans worldwide and is associated with reduced sprint and power performance in both elite athletes and the general population. α-Actinin-3 deficiency is also associated with reduced muscle mass and strength, increased sarcopenic risk in the elderly, and modifies disease severity and progression in a number of neuromuscular disorders such as Duchenne muscular dystrophy (DMD). Using an Actn3 knockout mouse model, we now show that α-actinin-3 plays a key role in the regulation of protein synthesis and breakdown in skeletal muscle, and its influence on muscle mass begins during early postnatal muscle development.

The ACTN3 577XX Null Genotype Is Associated with Low Left Ventricular Dilation-Free Survival Rate in Patients with Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a fatal progressive muscle-wasting disease caused by mutations in the DMD gene. Dilated cardiomyopathy is the leading cause of death in DMD; therefore, further understanding of this complication is essential to reduce morbidity and mortality. A common null variant (R577X) in the ACTN3 gene, which encodes α-actinin-3, has been studied in association with muscle function in healthy individuals; however it has not yet been examined in relationship to the cardiac phenotype in DMD. In this study, we determined the ACTN3 genotype in 163 patients with DMD and examined the correlation between ACTN3 genotypes and echocardiographic findings in 77 of the 163 patients. The genotypes 577RR(RR), 577RX(RX) and 577XX(XX) were identified in 13 (17%), 44 (57%) and 20 (26%) of 77 patients, respectively. We estimated cardiac involvement-free survival rate analyses using Kaplan-Meier curves. Remarkably, the left ventricular dilation (> 55 mm)-free survival rate was significantly lower in patients with the XX null genotype (P < 0.01). The XX null genotype showed a higher risk for LV dilation (hazard ratio 9.04). This study revealed that the ACTN3 XX null genotype was associated with a lower left ventricular dilation-free survival rate in patients with DMD. These results suggest that the ACTN3 genotype should be determined at the time of diagnosis of DMD to improve patients' cardiac outcomes.

Condyle modeling stability, craniofacial asymmetry and ACTN3 genotypes: Contribution to TMD prevalence in a cohort of dentofacial deformities.

Craniofacial asymmetry, mandibular condylar modeling and temporomandibular joint disorders are common comorbidities of skeletally disproportionate malocclusions, but etiology of occurrence together is poorly understood. We compared asymmetry, condyle modeling stability and temporomandibular health in a cohort of 128 patients having orthodontics and orthognathic surgery to correct dentofacial deformity malocclusions. We also compared ACTN3 and ENPP1 genotypes for association to clinical conditions. Pre-surgical posterior-anterior cephalometric and panometric radiographic analyses; jaw pain and function questionnaire and clinical examination of TMD; and SNP-genotype analysis from saliva samples were compared to assess interrelationships. Almost half had asymmetries in need of surgical correction, which could be subdivided into four distinct morphological patterns. Asymmetric condyle modeling between sides was significantly greater in craniofacial asymmetry, but most commonly had an unanticipated pattern. Often, longer or larger condyles occurred on the shorter mandibular ramus side. Subjects with longer ramus but dimensionally smaller condyles were more likely to have self-reported TMD symptoms (p = 0.023) and significantly greater clinical diagnosis of TMD (p = 0 .000001), with masticatory myalgia most prominent. Genotyping found two significant genotype associations for ACTN3 rs1671064 (Q523R missense) p = 0.02; rs678397 (intronic SNP) p = 0.04 and one significant allele association rs1815739 (R577X nonsense) p = 0.00. Skeletal asymmetry, unusual condyle modeling and TMD are common and interrelated components of many dentofacial deformities. Imbalanced musculoskeletal functional adaptations and genetic or epigenetic influences contribute to the etiology, and require further investigation.

Effect of ACTN3 Genotype on Sports Performance, Exercise-Induced Muscle Damage, and Injury Epidemiology.

Genetic factors play a significant role in athletic performance and its related phenotypes such as power, strength and aerobic capacity. In this regard, the lack of a muscle protein due to a genetic polymorphism has been found to affect sport performance in a wide variety of ways. α-actinin-3 is a protein located within the skeletal muscle with a key role in the production of sarcomeric force. A common stop-codon polymorphism (rs1815739; R577X) in the gene that codes for α-actinin-3 (ACTN3) produces individuals with the XX genotype that lack expression of a functional α-actinin-3. In contrast, individuals with the R-allele (i.e., RX vs. RR genotypes) in this polymorphism can express α-actinin-3. Interestingly, around ~18% of the world population have the XX genotype and much has been debated about why a polymorphism that produces a lack of a muscle protein has endured natural selection. Several investigations have found that α-actinin-3 deficiency due to XX homozygosity in the ACTN3 R577X polymorphism can negatively affect sports performance through several structural, metabolic, or signaling changes. In addition, new evidence suggests that α-actinin-3 deficiency may also impact sports performance through indirect factors such a higher risk for injury or lower resistance to muscle-damaging exercise. The purpose of this discussion is to provide a clear explanation of the effect of α-actinin-3 deficiency due to the ACTN3 XX genotype on sport. Key focus has been provided about the effect of α-actinin-3 deficiency on morphologic changes in skeletal muscle, on the low frequency of XX athletes in some athletic disciplines, and on injury epidemiology.

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.

FREQUENCY OF GENE ACE I POLYMORPHISM I-D IN ATHLETES OF DIFFERENT SPORTS

ABSTRACT Introduction: The angiotensin-converting enzyme I-D (ACE) polymorphism gene is one of the most widely investigated genetic variations in sports science. Apparently, allele I is related to endurance sports, while allele D is related to power-strength activities. Nevertheless, studies have presented controversial results when it comes as to its occurrence in a variety of sports. Objective: This study aims to evaluate the frequency of gene ACE polymorphism I-D in professional athletes of collective or individual sports. Methods: Five mL blood were collected from 189 subjects divided into two groups: athletes (AG, n=127, wrestling, taekwondo, soccer, futsal and handball) and non-athletes (NAG, n=62). The athletes group was subdivided by group modalities, into: collective and individual. Both groups were further subdivided into male and female. Thus, we have the groups FAC= collective female, FAI= individual female, MAC= collective male, and MAI= individual male. The statistical analysis was carried out by frequency test, and the Hardy- Weinberg equilibrium by the x² test. Results: The results for the AG group indicated the following frequencies: DD=7%, ID=44% and II=49%. Allele frequency: D=29% and I=71%. For the NAG, the results were: DD=6.5%, ID=45.2% and II=48%. Allele frequency: D=29% and I=71%. The AG genotypic and allele frequencies did not differ statistically from those of the NAG (p= 0.982 and p= 0.984, respectively). However, we noticed that the genotypes II and ID frequencies were significantly higher than those of the DD. Conclusion: It can be concluded that the genotypic and allelic I-D frequencies of the ACE gene do not seem to influence performance in either group or individual sports. ACTN3 genotype frequencies did not vary significantly between male and female control subjects, and overall, there was no significant deviation from Hardy-Weinberg (H-W) equilibrium. Level of evidence I; Diagnostic studies–Investigating diagnostic test.

A statistical model for ACTN3 genotype in elite power and speed athletes

The presence of R allele in R577X polymorphism of ACTN3 gene is responsible for expression of α-actinin-3 protein in fast glycolytic muscle fiber with a key role in structure and metabolism. The ACTN3 R577X gene polymorphism was found to be associated with strength and power performance. The aim of this study was to investigate the association between the ACTN3 R577X polymorphism and elite power/speed performance and to determine its relationship to the power/speed athletic status (elite athlete and nonathlete) in 48 subjects (23 power/speed athletes and 25 nonathletes) from Indian cohort. The association analysis did not show any significant association when conducted for all genotypes (RR vs RX vs XX) in athletes and nonathletes (p > 0.05). The association of R allele dominant (RR+XX) model and X allele dominant (RX+XX) model was also not significant (p > 0.05) when compared for athletic and nonathletic status, however, the frequency of RR genotype was higher in athletes than in nonathletes. The odds of becoming power/speed athlete with the possession of RR genotype and R allele carriage (RR+RX) was higher, although the prediction was not significant (p > 0.05). It can be inferred on the basis of selected samples that the possession of RR genotype or R allele does not provide any significant advantage for being power/speed athlete.

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.

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.

&amp;lt;I&amp;gt;ACTN3&amp;lt;/I&amp;gt; R577X Polymorphism Impacts Glucose Consumption at Simulated High Altitude

Introduction: High altitude acclimatization is a process that involve several physiological adjustments, which may increase glucose metabolism because of acute hypoxic exposure. Native highlanders like Tibetans show an increased anaerobic glucose metabolism and a higher proportion of type I muscle fiber than lowlanders. Actin filaments are anchored to the Z line of the sarcomere by a protein called alpha-actinin that exist in two isoforms in the muscle (ACTN2 and ACTN3), however ACTN3 is present only in type II fibers, especially in type IIx. Homozygous individuals for a 577X polymorphism in the ACTN3 gene do not express ACTN3 and seem to be more type I muscle fiber than homozygous individuals 577R. The aim of this study was to compare the glucose consumption response of individuals with different ACTN3 genotypes at simulated 4,500 m altitude. Materials & Methods: Twenty-three volunteers spent four hours exposed to a simulated altitude of 4,500 m inside a normobaric hypoxia chamber. Lactate and glucose concentrations, SpO2 and heart rate were analyzed immediately before entering the chamber and at each hour during the exposure. Results: Glucose after four hours of exposure to hypoxia was different between groups, with RX (68.1 ± 11.7 mg/dl) and RR (71.7 ± 14.4 mg/dl) showing a decreased blood glucose compared to XX (88.7 ± 14.1 mg/dl), indicating an increased dependence on glucose metabolism in individuals with at least one R allele after exposure at 4,500 m simulated altitude. Conclusions: We concluded that individuals with at least one R allele of the ACTN3 R577X gene polymorphism consume more glucose than the ones with XX genotype.

ACTN-3 Genotype, Body Composition, Fitness, and +Gz Tolerance in Senior Cadets

BACKGROUND: This study aimed to investigate the relationships among ACTN-3, body composition, fitness, and +Gz tolerance for senior cadet training development and their safe task performance.METHODS: The subjects were all senior cadets (N = 68) at the Korea Air Force Academy. All cadets are required to pass a physical fitness test (3-km running, sit-ups, push-ups) and body composition test on a semiannual basis. Isokinetic muscle function (strength and endurance), +Gz test (+6 Gz ⋅ 30 s-1), and target gene (ACTN-3) were analyzed.RESULTS: The effects of body composition and physical fitness along with the relationship of the ACTN-3 genotype to the +6 Gz test results were determined. Consequently, no significant difference was found concerning the effect of ACTN-3 on the +6 Gz test result, body composition, and physical fitness; however, body fat (%) and isokinetic muscle strength (peak torque right leg extension and left leg flexion) showed significance between the pass and failure groups in the +Gz test.DISCUSSION: The cadets of the Korea Air Force Academy showed dominant fast genetic expression type based on their ACTN-3 genotype [RR and RX (N = 51, 75%) > XX (N = 17, 25%)]. Body fat (%) and isokinetic muscle strength (PT R EX, L FL) can be more effective predictors in the +6 Gz test for cadet training. Another speculation is that more RR- and RX-type-oriented training can promote cadets' Gz tolerance from the isokinetic factors such as high peak torque and low fatigue index.Shin S, Jee H. ACTN-3 genotype, body composition, fitness, and +Gz tolerance in senior cadets. Aerosp Med Hum Perform. 2019; 90(12):1055-1060.

Association between ACTN3 and acute mountain sickness

BackgroundDuring the process of acclimatization, when our organism needs to adjust several metabolic processes in the attempt of establishing a better oxygenation, it is normal that individuals present some symptoms that can lead to the disease of the mountain. However, not everyone presents such symptoms and individuals native of high altitudes regions present genetic differences compared to natives of low altitudes which can generate a better acute adaptation. One of these differences is the higher proportion of type I muscle fibers, which may originate from the R577X polymorphism of the ACTN3 gene. The aim of this study was to compare the response of individuals with different ACTN3 genotypes at simulated 4500 m altitude on the presence of Acute Mountain Sickness (AMS) symptoms. Twenty-three volunteers (RR = 7, RX = 8, XX = 8) spent 4 hours exposed to a simulated altitude of 4500 m inside a normobaric hypoxia chamber. Lactate and glucose concentrations, SpO2, heart rate and the symptoms of AMS were analyzed immediately before entering the chamber and at each hour of exposure. Statistical analysis was performed using IBM SPSS Statistics 21 software.ResultsOur results point to an association between AMS symptoms and the presence of R allele from R577X polymorphism.ConclusionWe conclude that individuals with at least one R allele of the R577X polymorphism seems to be more susceptible to the effects of hypoxia during the acclimatization process and may develop AMS symptoms.

ACTN3 genotype distribution across horses representing different utility types and breeds

In horses, the identification of the genetic background of phenotypic variation, especially with regard to performance characteristics and predisposition to effort, has been extensively studied. As α-actinin-3 function is related to the regulation of muscle contraction and cell metabolism, the ACTN3 gene is considered one of the main genetic factors determining muscle strength. The aim of the present study was to assess the genotype distribution of two SNP variants within the equine ACTN3 gene (g.1104G > A and c.2334C > T) across different utility types and horse breeds. The analyses were performed on five breeds representing horses of different types, origins and utilities according to performance (in total 877 horses): primitive (Polish koniks; Hucul horses), draught (Polish heavy draught) and light (Thoroughbred and Arabian horses). Two polymorphisms within the ACTN3 gene locus were genotyped and genotype and allele frequency were compared across populations in order to verify if the identified differences contribute to the phenotypic variation observed in horse breeds. The present study allowed confirmation of the significant differences in genotype distribution of g.1104G > A localized in the promoter region between native breeds and racehorse breeds such as Thoroughbreds and Arabians. The allele/genotype variations between primitive and light breeds confirmed that the analysed variant was under selection pressure and can be correlated with racing ability. Moreover, the significant differences for the c.2334C > T genotype frequency between Arabian horses and other breeds indicate its relationship with endurance and athletic performance. The predominance of the T allele (85%) in Arabians suggests that the T variant was favoured during selection focused on improving stamina and could be one of the genetic factors determining endurance ability. Further research is needed to confirm the association of both polymorphisms with exact racing and/or riding results.

The Role of Genetic Profile in Functional Performance Adaptations to Exercise Training or Physical Activity: A Systematic Review of the Literature.

Background: Variations in genotype may contribute to heterogeneity in functional adaptations to exercise. Methods: A systematic search of eight databases was conducted, and 9,696 citations were screened. Results: Eight citations from seven studies measuring 10 single-nucleotide polymorphisms and nine different functional performance test outcomes were included in the review. There was one observational study of physical activity and six experimental studies of aerobic or resistance training. The ACE (D) allele, ACTN3 (RR) genotype, UCP2 (GG) genotype, IL-6-174 (GG) genotype, TNF-α-308 (GG) genotype, and IL-10-1082 (GG) genotype all predicted significantly superior adaptations in at least one functional outcome in older men and women after prescribed exercise or in those with higher levels of physical activity. Conclusion: There is a small amount of evidence that older adults may have better functional outcomes after exercise/physical activity if they have specific alleles related to musculoskeletal function or inflammation. However, more robust trials are needed.