The associations of ACE polymorphisms with physical, physiological and skill parameters in adolescents

Association of ACE gene polymorphisms with in-stent restenosis by stent type (biomime, supraflex, xience)

INTRODUCTION

Angiotensin Converting Enzyme or ACE is an exo-peptidase that causes the conversion of angiotensin I to angiotensin II, vasoconstriction, and aldosterone production. ACE gene polymorphism (I/D) affects enzyme activity and the risk of coronary artery disease or CAD.

AIMS

To examine the role of ACE (I/D) Gene Polymorphisms by Stent Types (Biomime, Supraflex, Xience) the Ace gene allele and genotype frequencies were determined in patients who underwent angioplasty.

MATERIAL & METHODS

Patients with in-stent restenosis (ISR+) (N = 53) and patients as non-ISR group (ISR-) (N = 68) have been enrolled in this study based on follow-up angiography > 1 year after PCI. Frequencies of allele and genotypes of the ACE (I/D) variant were determined using polymerase chain reaction (PCR).

RESULTS

The genotypes and allele frequencies were not significantly different between the studied populations (p-Values > 0.05). However, there was a significant difference between people with a history of Clopidogrel use in the ISR- and ISR + groups observed (p-Values > 0.005).

CONCLUSION

In the present study, there was no statistically significant relationship between ACE (I/D) gene polymorphism and the incidence of restenosis in patients who underwent repeat angiography. The results showed that the number of patients who received Clopidogrel in the ISR + group was significantly less than the ISR- group. This issue can indicate the inhibitory effect of Clopidogrel in the recurrence of stenosis.

Genetic Profile in Genes Associated with Sports Injuries in Elite Endurance Athletes

Injuries are a complex trait that can stem from the interaction of several genes. The aim of this research was to examine the relationship between muscle performance-related genes and overuse injury risk in elite endurance athletes, and to examine the feasibility of determining a total genotype score that significantly correlates with injury. A cohort of 100 elite endurance athletes (50 male and 50 female) was selected. AMPD1 (rs17602729), ACE (rs4646994), ACTN3 (rs1815739), CKM (rs8111989) and MLCK ([rs2849757] and [rs2700352]) polymorphisms were genotyped by using real-time polymerase chain reaction (real time-PCR). Injury characteristics during the athletic season were classified following the Consensus Statement for injuries evaluation. The mean total genotype score (TGS) in non-injured athletes (68.263±13.197 arbitrary units [a.u.]) was different from that of injured athletes (50.037±17.293 a.u., p<0.001). The distribution of allelic frequencies in the AMPD1 polymorphism was also different between non-injured and injured athletes (p<0.001). There was a TGS cut-off point (59.085 a.u.) to discriminate non-injured from injured athletes with an odds ratio of 7.400 (95% CI 2.548-21.495, p<0.001). TGS analysis appears to correlate with elite endurance athletes at higher risk for injury. Further study may help to develop this as one potential tool to help predict injury risk in this population.

Genetic profile in genes associated with muscle injuries and injury etiology in professional soccer players

Many causes define injuries in professional soccer players. In recent years, the study of genetics in association with injuries has been of great interest. The purpose of this study was to examine the relationship between muscle injury-related genes, injury risk and injury etiology in professional soccer players. In a cross-sectional cohort study, one hundred and twenty-two male professional football players were recruited. AMPD1 (rs17602729), ACE (rs4646994), ACTN3 (rs1815739), CKM (rs8111989) and MLCK (rs2849757 and rs2700352) polymorphisms were genotyped by using Single Nucleotide Primer Extension (SNPE). The combined influence of the six polymorphisms studied was calculated using a total genotype score (TGS). A genotype score (GS) of 2 was assigned to the “protective” genotype for injuries, a GS of 1 was assigned to the heterozygous genotype while a GS of 0 was assigned to the “worst” genotype. Injury characteristics and etiology during the 2021/2022 season were classified following a Consensus Statement for injuries recording. The distribution of allelic frequencies in the AMPD1 and MLCK c.37885C&gt;A polymorphisms were different between non-injured and injured soccer players (p &lt; 0.001 and p = 0.003, respectively). The mean total genotype score (TGS) in non-injured soccer players (57.18 ± 14.43 arbitrary units [a.u.]) was different from that of injured soccer players (51.71 ± 12.82 a.u., p = 0.034). There was a TGS cut-off point (45.83 a.u.) to discriminate non-injured from injured soccer players. Players with a TGS beyond this cut-off had an odds ratio of 1.91 (95%CI: 1.14–2.91; p = 0.022) to suffer an injury when compared with players with lower TGS. In conclusion, TGS analysis in muscle injury-related genes presented a relationship with professional soccer players at increased risk of injury. Future studies will help to develop this TGS as a potential tool to predict injury risk and perform prevention methodology in this cohort of football players.

Genetic profiles to identify talents in elite endurance athletes and professional football players

The genetic profile that is needed to identify talents has been studied extensively in recent years. The main objective of this investigation was to approach, for the first time, the study of genetic variants in several polygenic profiles and their role in elite endurance and professional football performance by comparing the allelic and genotypic frequencies to the non-athlete population. In this study, genotypic and allelic frequencies were determined in 452 subjects: 292 professional athletes (160 elite endurance athletes and 132 professional football players) and 160 non-athlete subjects. Genotyping of polymorphisms in liver metabolisers (CYP2D6, GSTM1, GSTP and GSTT), iron metabolism and energy efficiency (HFE, AMPD1 and PGC1a), cardiorespiratory fitness (ACE, NOS3, ADRA2A, ADRB2 and BDKRB2) and muscle injuries (ACE, ACTN3, AMPD1, CKM and MLCK) was performed by Polymerase Chain Reaction-Single Nucleotide Primer Extension (PCR-SNPE). The combination of the polymorphisms for the “optimal” polygenic profile was quantified using the genotype score (GS) and total genotype score (TGS). Statistical differences were found in the genetic distributions between professional athletes and the non-athlete population in liver metabolism, iron metabolism and energy efficiency, and muscle injuries (p<0.001). The binary logistic regression model showed a favourable OR (odds ratio) of being a professional athlete against a non-athlete in liver metabolism (OR: 1.96; 95% CI: 1.28–3.01; p = 0.002), iron metabolism and energy efficiency (OR: 2.21; 95% CI: 1.42–3.43; p < 0.001), and muscle injuries (OR: 2.70; 95% CI: 1.75–4.16; p < 0.001) in the polymorphisms studied. Genetic distribution in professional athletes as regards endurance (professional cyclists and elite runners) and professional football players shows genetic selection in these sports disciplines.

Genetics and sports performance: the present and future in the identification of talent for sports based on DNA testing

The impact of genetics on physiology and sports performance is one of the most debated research aspects in sports sciences. Nearly 200 genetic polymorphisms have been found to influence sports performance traits, and over 20 polymorphisms may condition the status of the elite athlete. However, with the current evidence, it is certainly too early a stage to determine how to use genotyping as a tool for predicting exercise/sports performance or improving current methods of training. Research on this topic presents methodological limitations such as the lack of measurement of valid exercise performance phenotypes that make the study results difficult to interpret. Additionally, many studies present an insufficient cohort of athletes, or their classification as elite is dubious, which may introduce expectancy effects. Finally, the assessment of a progressively higher number of polymorphisms in the studies and the introduction of new analysis tools, such as the total genotype score (TGS) and genome-wide association studies (GWAS), have produced a considerable advance in the power of the analyses and a change from the study of single variants to determine pathways and systems associated with performance. The purpose of the present study was to comprehensively review evidence on the impact of genetics on endurance- and power-based exercise performance to clearly determine the potential utility of genotyping for detecting sports talent, enhancing training, or preventing exercise-related injuries, and to present an overview of recent research that has attempted to correct the methodological issues found in previous investigations.

Muscle Work and Its Relationship with ACE and ACTN3 Polymorphisms Are Associated with the Improvement of Explosive Strength

Background: The potential influence of genetics in athletic performance allows the search for genetic profiles associated with muscular work for the orientation of strength training and sports selection. The purpose of the study was to analyze four muscular exercises for effectiveness in improving explosive strength variables, associated to the genetics in Angiotensin Converting Enzyme (ACE) and α-actinin-3 (ACTN3) polymorphisms. Methods: A randomized controlled trial was conducted on a sample of 80 subjects allocated into four groups: concentric muscle work (CMW), eccentric muscle work (EMW), concentric-eccentric muscle (C-EMW) work and isometric muscular work (IMW), by block and gender randomization. Vertical jump, long jump, power jump, and speed were measured to study explosive strength. Genotypic frequencies of ACE (rs4646994) and ACTN3 (rs1815739) were obtained by polymerase chain reaction. Results: ACE gen showed significant improvements regarding the DD genotype in the Sargent test (p = 0.003) and sprint velocity test (p = 0.017). In the ACTN3 gene, the RR variable obtained improvement results with regard to RX and XX variables in long jump (p < 0.001), Sargent test (p < 0.001) and power jump (p = 0.004). Conclusions: The selected genes demonstrated an influence on the muscle work and the improvement in explosive strength variables with a decisive role regarding the type of muscle work performed.

Genetic test for the personalization of sport training

Genetic variants may contribute to confer elite athlete status. However, this does not mean that a person with favourable genetic traits would become a champion because multiple genetic interactions and epigenetic contributions coupled with confounding environmental factors shape the overall phenotype. This opens up a new area in sports genetics with respect to commercial genetic testing. The analysis of genetic polymorphisms linked to sport performance would provide insights into the potential of becoming an elite endurance or power performer. This mini-review aims to highlight genetic interactions that are associated with performance phenotypes and their potentials to be used as markers for talent identification and trainability.

Do ACE and CKMM gene variations have potent effects on physical performance in inactive male adolescents?

We studied to ascertain whether the ACE and/or CKMM genotypes independently influence the baseline level of some sport performances in 613 inactive male adolescents (mean ± SD age: 13.24 ± 0.28 years). All DNA samples were extracted and genotyped for ACE I/D and CKMM A/G polymorphisms using a PCR based procedure. One-way analysis of covariance was used to examine the discrepancies in the research phenotypes among various ACE and CKMM polymorphisms. The comparisons of genotype and allele frequencies between adolescents with the best and the worst performances were calculated and analyzed by the Chi square test. All procedures were approved by Medical University Ethics Committee. Written informed consent signed and approved by all subject`s parents were obtained. We observed the effect of the ACE and CKMM polymorphisms on VO_2max (P = 0.001 & P = 0.001 respectively). ACE and CKMM genotypes differed between groups (< 90th vs. ≥ 90) in the multi-stage 20 m shuttle run (P = 0.001 and 0.001). ACE allele frequencies differed between groups (< 90th vs. ≥ 90) in the multi-stage 20-m shuttle run (P = 0.001). This study suggests that the ACE and CKMM polymorphisms influence the endurance performance phenotype in non-trained adolescent males.

Association between the PPARa and PPARGCA gene variations and physical performance in non-trained male adolescents

The purpose of the research was to examine if some genetic variations are associated with some endurance, power and speed performances (multi-stage 20-m shuttle run, standing broad jump, 20 m sprint test and Abalakov jump) in a group of 586 non-trained male adolescents (mean ± SD age: 13.20 ± 0.25 years). Polymorphisms in PPARa and PPARGC1A implicated in physical performance traits were analyzed. DNA was extracted and the samples were genotyped for PPARa and PPARGC1A polymorphisms by a PCR based method followed by gel electrophoresis. The discrepancies in the study phenotypes among variations of the PPARa and PPARGC1A polymorphisms were analyzed by one-way analysis of covariance (ANCOVA), after age, weight and height adjustment. To examine whether the genotype and allele frequencies between adolescents with high and low performances were different, we divided them into two groups: ≥ 90th and < 90th of the percentile. The genotype and allele frequencies between adolescents with high and low performances were compared with the Chi square test. Our analysis demonstrated the effects of the PPARa and PPARGC1A polymorphisms only on [Formula: see text] (p = 0.010 and p = 0.010 respectively). Also, we observed significant differences in PPARa and PPARGC1A genotypes (p = 0.034 and p = 0.024) or allele frequencies (p = 0.031 and p = 0.001) between groups for the multi-stage 20-m shuttle run test. Findings of this research suggest that both the PPARa and PPARGC1A polymorphisms are associated with estimating endurance-related phenotype and endurance capacity in male non-athletes adolescents.

An innovative way to highlight the power of each polymorphism on elite athletes phenotype expression

The purpose of this study was to determine the probability of soccer players having the best genetic background that could increase performance, evaluating the polymorphism that are considered Performance Enhancing Polymorphism (PEPs) distributed on five genes: PPARα, PPARGC1A, NRF2, ACE e CKMM. Particularly, we investigated how each polymorphism works directly or through another polymorphism to distinguish elite athletes from non-athletic population. Sixty professional soccer players (age 22.5 ± 2.2) and sixty healthy volunteers (age 21.2± 2.3) were enrolled. Samples of venous blood was used to prepare genomic DNA. The polymorphic sites were scanned using PCR-RFLP protocols with different enzyme. We used a multivariate logistic regression analysis to demonstrate an association between the five PEPs and elite phenotype. We found statistical significance in NRF2 (AG/GG genotype) polymorphism/soccer players association (p < 0.05) as well as a stronger association in ACE polymorphism (p =0.02). Particularly, we noticed that the ACE ID genotype and even more the II genotype are associated with soccer player phenotype. Although the other PEPs had no statistical significance, we proved that some of these may work indirectly, amplifying the effect of another polymorphism; for example, seems that PPARα could acts on NRF2 (GG) enhancing the effect of the latter, notwithstanding it had not shown a statistical significance.

In conclusion, to establish if a polymorphism can influence the performance, it is necessary to understand how they act and interact, directly and indirectly, on each other.

Individual and Combined Influence of ACE and ACTN3 Genes on Muscle Phenotypes in Polish Athletes

Orysiak, J, Mazur-Różycka, J, Busko, K, Gajewski, J, Szczepanska, B, and Malczewska-Lenczowska, J. Individual and combined influence of ACE and ACTN3 genes on muscle phenotypes in polish athletes. J Strength Cond Res 32(10): 2776-2782, 2018-The aim of this study was to examine the association between angiotensin-converting enzyme (ACE) and α-actinin-3 (ACTN3) genes, independently or in combination, and muscle strength and power in male and female athletes. The study involved 398 young male (n = 266) and female (n = 132) athletes representing various sport disciplines (ice hockey, canoeing, swimming, and volleyball). All were Caucasians. The following measurements were taken: height of jump and mechanical power in countermovement jump (CMJ) and spike jump (SPJ), and muscle strength of 10 muscle groups (flexors and extensors of the elbow, shoulder, hip, knee, and trunk). The insertion-deletion (I/D) polymorphism of ACE and the R577X polymorphism of ACTN3 were typed using polymerase chain reaction (PCR) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), respectively. The genotype distribution of the ACE and ACTN3 genes did not differ significantly between groups of athletes for either sex. There was no association between ACE and ACTN3 genotypes (alone or in combination) and sum of muscle strength, height of jump or mechanical power in both jump tests (CMJ and SPJ) for male and female athletes. These findings do not support an influential role of the ACE and ACTN3 genes in determining power/strength performance of elite athletes.

Evaluation of ACE gene I/D polymorphism in Iranian elite athletes

Background:

Angiotensin converting enzyme (ACE) is an important gene, which is associated with the successful physical activity. The ACE gene has a major polymorphism (I/D) in intron 16 that determines its plasma and tissue levels. In this study, we aimed to determine whether there is an association between this polymorphism and sports performance in our studied population including elite athletes of different sports disciplines. We investigated allele frequency and genotype distribution of the ACE gene in 156 Iranian elite athletes compared to 163 healthy individuals. We also investigated this allele frequency between elite athletes in three functional groups of endurance, power, and mixed sports performances.

Materials and Methods:

DNA was extracted from peripheral blood, and polymerase chain reaction (PCR) method was performed on intron 16 of the ACE gene. The ACE genotype was determined for each subject. Statistical analysis was performed by SPSS 15, and results were analyzed by Chi-Square test.

Results:

There was a significant difference in genotype distribution and allele frequency of the ACE gene in athletes and control group (P = 0.05, P = 0.03, respectively). There was also a significant difference in allele frequency of the ACE gene in 3 groups of athletes with different sports disciplines (P = 0.045). Proportion of the ACE gene D allele was greater in elite endurance athletes (37 high-distance cyclists) than two other groups.

Conclusions:

Findings of the present study demonstrated that there is an association between the ACE gene I/D polymorphism and sports performance in Iranian elite athletes.

Genetic influence on athletic performance

PURPOSE OF REVIEW

To summarize the existing literature on the genetics of athletic performance, with particular consideration for the relevance to young athletes.

RECENT FINDINGS

Two gene variants, ACE I/D and ACTN3 R577X, have been consistently associated with endurance (ACE I/I) and power-related (ACTN3 R/R) performance, though neither can be considered predictive. The role of genetic variation in injury risk and outcomes is more sparsely studied, but genetic testing for injury susceptibility could be beneficial in protecting young athletes from serious injury. Little information on the association of genetic variation with athletic performance in young athletes is available; however, genetic testing is becoming more popular as a means of talent identification. Despite this increase in the use of such testing, evidence is lacking for the usefulness of genetic testing over traditional talent selection techniques in predicting athletic ability, and careful consideration should be given to the ethical issues surrounding such testing in children.

SUMMARY

A favorable genetic profile, when combined with an optimal training environment, is important for elite athletic performance; however, few genes are consistently associated with elite athletic performance, and none are linked strongly enough to warrant their use in predicting athletic success.

G16R single nucleotide polymorphism but not haplotypes of the β(2)-adrenergic receptor gene alters cardiac output in humans

Variation in genes encoding the β(2)-adrenergic receptor (ADRB2) and angiotensin-converting enzyme (ACE) may influence Q (cardiac output). The 46G>A (G16R) SNP (single nucleotide polymorphism) has been associated with β(2)-mediated vasodilation, but the effect of ADRB2 haplotypes on Q has not been studied. Five SNPs within ADRB2 (46G>A, 79C>G, 491C>T, 523C>A and 1053G>C by a pairwise tagging principle) and the I/D (insertion/deletion) polymorphism in ACE were genotyped in 143 subjects. Cardiovascular variables were evaluated by the Model flow method at rest and during incremental cycling exercise. Only the G16R polymorphism was associated with Q. In carriers of the Arg(16) allele, Q(rest) (resting Q) was 0.4 [95% CI (confidence interval), 0.0-0.7] l/min lower than in G16G homozygotes (P=0.048). During exercise, the increase in Q was by 4.7 (95% CI, 4.3-5.2) l/min per litre increase in pulmonary Vo(2) (oxygen uptake) in G16G subjects, but the increase was 0.5 (0.0-0.9) l/min lower in Arg16 carriers (P=0.035). A similar effect size was observed for the Arg16 haplotypes ACCCG and ACCCC. No interaction was found between ADRB2 and ACE polymorphisms. During exercise, the increase in Q was 0.5 (CI, 0.0 -1.0) l/min greater in ACE I/I carriers compared with I/D and D/D subjects (P=0.054). In conclusion, the ADRB2 Arg16 allele in humans is associated with a lower Q both at rest and during exercise, overriding the effects of haplotypes.

The association of ACE, ACTN3 and PPARA gene variants with strength phenotypes in middle school-age children

The aim of the study was to determine the association between ACE I/D, ACTN3 R577X and PPARA intron 7 G/C gene polymorphisms and strength-related traits in 457 middle school-age children (219 boys and 238 girls; aged 11 ± 0.4 years). The assessment of different phenotypes was conducted with a number of performance tests. Gene polymorphisms were determined by PCR. The ACE D allele was associated with high results of standing long-jump test in boys [II 148.3 (16.3) cm, ID 152.6 (19.6) cm, DD 158.2 (19.1) cm; P = 0.037]. The ACTN3 R allele was associated with high results of performance tests in males only in combination with other genes (standing long-jump test: P = 0.021; handgrip strength test: P < 0.0001). Furthermore, the male carriers of the PPARA gene C allele demonstrated the best results of handgrip strength testing than GG homozygotes [GG 14.6 (4.0) kg, GC/CC 15.7 (4.3) kg; P = 0.048]. Thus, the ACE, ACTN3 and PPARA gene variants are associated with strength-related traits in physically active middle school-age boys.

Genetic aspects of skeletal muscle strength and mass with relevance to sarcopenia

Skeletal muscle is a highly heritable quantitative trait, with heritability estimates ranging 30-85% for muscle strength and 50-80% for lean mass. That strong genetic contribution indicates the possibility of using genetic information to individualize treatments for sarcopenia or even aid in prevention strategies through the use of genetic screening prior to the functional limitations. Though these possibilities provide the rationale for genetic studies of skeletal muscle traits, few genes have been identified that appear to contribute to variation in either skeletal muscle strength or mass phenotypes, and sarcopenia per se is remarkably understudied as a trait in this regard. This review examines the heritability of skeletal muscle traits, findings of linkage and genome-wide association analyses and impact of specific genes and gene-sequence variants on these traits as relevant to sarcopenia. Despite considerable work in the area, the genetic underpinnings of skeletal muscle traits remain largely unknown and the genetic aspects of sarcopenia are even less clear. Large-scale longitudinal clinical studies relying on advanced genome-wide association and other techniques are needed to provide further insights into the genes and gene variants that contribute to skeletal muscle strength and mass, and ultimately to susceptibility to sarcopenia.

ACE I/D, ACTN3 R577X, PPARD T294C and PPARGC1A Gly482Ser polymorphisms and physical fitness in Taiwanese late adolescent girls

Physical performance of youth is influenced by various factors, including body composition, biological maturity status, level of habitual physical activity, and muscular strength. Muscular strength has been largely attributed to genetic effects. To exclude possible confounding effects from various acquired factors, this study examined the relationships between polymorphisms of the angiotensin-converting enzyme (ACE), α-actinin-3 (ACTN3), peroxisome proliferator-activated receptor delta (PPARD), and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PPARGC1A) genes and performance as measured by six fitness tests (handgrip strength of dominant hand, 30- and 60-s sit-ups, standing long jump, 60-m dash, and 800-m run) in 170 sedentary adolescent girls with the adjustment of anthropometric characteristics. We found that subjects with the ACE DD genotype were significantly heavier than those with I allele, while those with the ACTN3 RR genotype had higher fat-free mass percentage (FFM%) than those with the XX genotype. In addition, those with the PPARD TT genotype were significantly taller, heavier, and had a greater FFM than those with the CC genotype. Subjects with the ACE DD, ACTN3 RR and PPARD TC genotype had better performance in handgrip strength, 30- and 60-s sit-up tests, and standing long jump, respectively, when individual gene was analyzed independently after adjusting anthropometric characteristics. In the gene combination analysis, subjects with ACE DD, ACTN3 RR and PPARD TT genotype had significantly greater performance in handgrip strength. Overall, the results indicate that the genes studied have a modest influence on individual performance as assessed by specific fitness and strength tests in female late adolescents.

The ACE gene and human performance: 12 years on

Some 12 years ago, a polymorphism of the angiotensin I-converting enzyme (ACE) gene became the first genetic element shown to impact substantially on human physical performance. The renin-angiotensin system (RAS) exists not just as an endocrine regulator, but also within local tissue and cells, where it serves a variety of functions. Functional genetic polymorphic variants have been identified for most components of RAS, of which the best known and studied is a polymorphism of the ACE gene. The ACE insertion/deletion (I/D) polymorphism has been associated with improvements in performance and exercise duration in a variety of populations. The I allele has been consistently demonstrated to be associated with endurance-orientated events, notably, in triathlons. Meanwhile, the D allele is associated with strength- and power-orientated performance, and has been found in significant excess among elite swimmers. Exceptions to these associations do exist, and are discussed. In theory, associations with ACE genotype may be due to functional variants in nearby loci, and/or related genetic polymorphism such as the angiotensin receptor, growth hormone and bradykinin genes. Studies of growth hormone gene variants have not shown significant associations with performance in studies involving both triathletes and military recruits. The angiotensin type-1 receptor has two functional polymorphisms that have not been shown to be associated with performance, although studies of hypoxic ascent have yielded conflicting results. ACE genotype influences bradykinin levels, and a common gene variant in the bradykinin 2 receptor exists. The high kinin activity haplotye has been associated with increased endurance performance at an Olympic level, and similar results of metabolic efficiency have been demonstrated in triathletes. Whilst the ACE genotype is associated with overall performance ability, at a single organ level, the ACE genotype and related polymorphism have significant associations. In cardiac muscle, ACE genotype has associations with left ventricular mass changes in response to stimulus, in both the health and diseased states. The D allele is associated with an exaggerated response to training, and the I allele with the lowest cardiac growth response. In light of the I-allele association with endurance performance, it seems likely that other regulatory mechanisms exist. Similarly in skeletal muscle, the D allele is associated with greater strength gains in response to training, in both healthy individuals and chronic disease states. As in overall performance, those genetic polymorphisms related to the ACE genotype, such as the bradykinin 2 gene, also influence skeletal muscle strength. Finally, the ACE genotype may influence metabolic efficiency, and elite mountaineers have demonstrated an excess of I alleles and I/I genotype frequency in comparison to controls. Interestingly, this was not seen in amateur climbers. Corroboratory evidence exists among high-altitude settlements in both South America and India, where the I allele exists in greater frequency in those who migrated from the lowlands. Unfortunately, if the ACE genotype does influence metabolic efficiency, associations with peak maximal oxygen consumption have yet to be rigorously demonstrated. The ACE genotype is an important but single factor in the determinant of sporting phenotype. Much of the mechanisms underlying this remain unexplored despite 12 years of research.

Genetics of muscle strength and power: polygenic profile similarity limits skeletal muscle performance

Environmental and genetic factors influence muscle function, resulting in large variations in phenotype between individuals. Multiple genetic variants (polygenic in nature) are thought to influence exercise-related phenotypes, yet how the relevant polymorphisms combine to influence muscular strength in individuals and populations is unclear. In this analysis, 22 genetic polymorphisms were identified in the literature that have been associated with muscular strength and power phenotypes. Using typical genotype frequencies, the probability of any given individual possessing an "optimal" polygenic profile was calculated as 0.0003% for the world population. Future identification of additional polymorphisms associated with muscular strength phenotypes would most likely reduce that probability even further. To examine the genetic potential for muscular strength within a human population, a "total genotype score" was generated for each individual within a hypothetical population of one million. The population expressed high similarity in polygenic profile with no individual differing by more than seven genotypes from a typical profile. Therefore, skeletal muscle strength potential within humans appears to be limited by polygenic profile similarity. Future research should aim to replicate more genotype-phenotype associations for muscular strength, because only five common genetic polymorphisms identified to date have positive replicated findings.

ACTN3 genotype, athletic status, and life course physical capability: meta-analysis of the published literature and findings from nine studies

The ACTN3 R577X (rs1815739) genotype has been associated with athletic status and muscle phenotypes, although not consistently. Our objective was to conduct a meta-analysis of the published literature on athletic status and investigate its associations with physical capability in several new population-based studies. Relevant data were extracted from studies in the literature, comparing genotype frequencies between controls and sprint/power and endurance athletes. For life course physical capability, data were used from two studies of adolescents and seven studies in the Healthy Ageing across the Life Course (HALCyon) collaborative research program, involving individuals aged between 53 and 90+ years. We found evidence from the published literature to support the hypothesis that in Europeans the RR genotype is more common among sprint/power athletes compared with their controls. There is currently no evidence that the X allele is advantageous to endurance athleticism. We found no association between R577X and grip strength (P = 0.09, n = 7,672 in males; P = 0.90, n = 7,839 in females), standing balance, timed get up and go, or chair rises in our studies of physical capability. The ACTN3 R577X genotype is associated with sprint/power athletic status in Europeans, but does not appear to be associated with objective measures of physical capability in the general population. Hum Mutat 32:1–11, 2011. © 2011 Wiley-Liss, Inc.

Molecular genetic studies of gene identification for sarcopenia

Sarcopenia, which is characterized by a progressive decrease of skeletal muscle mass and function with aging, is closely related to several common diseases (such as cardiovascular and airway diseases) and functional impairment/disability. Strong genetic determination has been reported for muscle mass and muscle strength, two most commonly recognized and studied risk phenotypes for sarcopenia, with heritability ranging from 30 to 85% for muscle strength and 45-90% for muscle mass. Sarcopenia has been the subject of increasing genetic research over the past decade. This review is designed to comprehensively summarize the most important and representative molecular genetic studies designed to identify genetic factors associated with sarcopenia. We have methodically reviewed whole-genome linkage studies in humans, quantitative trait loci mapping in animal models, candidate gene association studies, newly reported genome-wide association studies, DNA microarrays and microRNA studies of sarcopenia or related skeletal muscle phenotypes. The major results of each study are tabulated for easy comparison and reference. The findings of representative studies are discussed with respect to their influence on our present understanding of the genetics of sarcopenia. This is a comprehensive review of molecular genetic studies of gene identification for sarcopenia, and an overarching theme for this review is that the currently accumulating results are tentative and occasionally inconsistent and should be interpreted with caution pending further investigation. Consequently, this overview should enhance recognition of the need to validate/replicate the genetic variants underlying sarcopenia in large human cohorts and animal. We believe that further progress in understanding the genetic etiology of sarcopenia will provide valuable insights into important fundamental biological mechanisms underlying muscle physiology that will ultimately lead to improved ability to recognize individuals at risk for developing sarcopenia and our ability to treat this debilitating condition.

The origin of Eastern European Jews revealed by autosomal, sex chromosomal and mtDNA polymorphisms

Background

This study aims to establish the likely origin of EEJ (Eastern European Jews) by genetic distance analysis of autosomal markers and haplogroups on the X and Y chromosomes and mtDNA.

Results

According to the autosomal polymorphisms the investigated Jewish populations do not share a common origin, and EEJ are closer to Italians in particular and to Europeans in general than to the other Jewish populations. The similarity of EEJ to Italians and Europeans is also supported by the X chromosomal haplogroups. In contrast according to the Y-chromosomal haplogroups EEJ are closest to the non-Jewish populations of the Eastern Mediterranean. MtDNA shows a mixed pattern, but overall EEJ are more distant from most populations and hold a marginal rather than a central position. The autosomal genetic distance matrix has a very high correlation (0.789) with geography, whereas the X-chromosomal, Y-chromosomal and mtDNA matrices have a lower correlation (0.540, 0.395 and 0.641 respectively).

Conclusions

The close genetic resemblance to Italians accords with the historical presumption that Ashkenazi Jews started their migrations across Europe in Italy and with historical evidence that conversion to Judaism was common in ancient Rome. The reasons for the discrepancy between the biparental markers and the uniparental markers are discussed.

Reviewers

This article was reviewed by Damian Labuda (nominated by Jerzy Jurka), Kateryna Makova and Qasim Ayub (nominated by Dan Graur).

Does the ACE I/D polymorphism, alone or in combination with the ACTN3 R577X polymorphism, influence muscle power phenotypes in young, non-athletic adults?

We investigated the association of the angiotensin converting enzyme gene (ACE) insertion/deletion (I/D) polymorphism, alone or in combination with the α-actinin-3 gene (ACTN3) R577X polymorphism, with jumping (vertical squat and counter-movement jump tests) and sprint ability (30 m dash) in non-athletic, healthy young adults [N = 281 (214 male), mean (SD) age 21 (2) years]. We did not observe any effect of the ACE I/D polymorphism on study phenotypes. We repeated the analyses separately in men and women and the results did not materially change. Likewise, the mean estimates of the study phenotypes were similar in subjects with the genotype combinations ACE II + ID and ACTN3 XX or ACE DD and ACTN3 RR + RX. We found no association between the ACE DD and ACTN3 RR + RX genotype combination and performance (≥90th of the sex-specific percentile). In summary, though the ACE I/D polymorphism is a strong candidate to modulate some exercise-related phenotypes or athletic performance status, this polymorphism, alone or in combination with the ACTN3 R577X polymorphism, does not seem to exert a major influence in the muscle 'explosive' power of young healthy adults, as assessed during multi-joint exercise tests.

Genetics and sports

INTRODUCTION

The limit of each individual to perform a given type of exercise depends on the nature of the task, and is influenced by a variety of factors, including psychology, environment and genetic make up. Genetics provide useful insights, as sport performances can be ultimately defined as a polygenic trait.

SOURCES OF DATA

We searched PubMed using the terms 'sports' and 'genetics' over the period 1990 to present.

AREAS OF AGREEMENT

The physical performance phenotypes for which a genetic basis can be suspected include endurance capacity, muscle performance, physiological attitude to train and ability of tendons and ligaments to withstand injury. Genetic testing in sport would permit to identify individuals with optimal physiology and morphology, and also those with a greater capacity to respond/adapt to training and a lesser chance of suffering from injuries.

AREAS OF CONTROVERSY

Ethical and practical caveats should be clearly emphasized. The translation of an advantageous genotype into a champion's phenotype is still influenced by environmental, psychological and sociological factors.

EMERGING AREAS FOR DEVELOPING RESEARCH

The current scientific evidence on the relationship between genetics and sports look promising. There is a need for additional studies to determine whether genome-wide genotyping arrays would be really useful and cost-effective. Since exercise training regulates the expression of genes encoding various enzymes in muscle and other tissues, genetic research in sports will help clarify several aspects of human biology and physiology, such as RNA and protein level regulation under specific circumstances.

The human gene map for performance and health-related fitness phenotypes: the 2006-2007 update

This update of the human gene map for physical performance and health-related fitness phenotypes covers the research advances reported in 2006 and 2007. The genes and markers with evidence of association or linkage with a performance or a fitness phenotype in sedentary or active people, in responses to acute exercise, or for training-induced adaptations are positioned on the map of all autosomes and sex chromosomes. Negative studies are reviewed, but a gene or a locus must be supported by at least one positive study before being inserted on the map. A brief discussion on the nature of the evidence and on what to look for in assessing human genetic studies of relevance to fitness and performance is offered in the introduction, followed by a review of all studies published in 2006 and 2007. The findings from these new studies are added to the appropriate tables that are designed to serve as the cumulative summary of all publications with positive genetic associations available to date for a given phenotype and study design. The fitness and performance map now includes 214 autosomal gene entries and quantitative trait loci plus seven others on the X chromosome. Moreover, there are 18 mitochondrial genes that have been shown to influence fitness and performance phenotypes. Thus,the map is growing in complexity. Although the map is exhaustive for currently published accounts of genes and exercise associations and linkages, there are undoubtedly many more gene-exercise interaction effects that have not even been considered thus far. Finally, it should be appreciated that most studies reported to date are based on small sample sizes and cannot therefore provide definitive evidence that DNA sequence variants in a given gene are reliably associated with human variation in fitness and performance traits.

Designer babies on tap? Medical students' attitudes to pre-implantation genetic screening

This paper describes two studies about the determinants of attitudes to pre-implantation genetic screening in a multicultural sample of medical students from the United States. Sample sizes were 292 in study 1 and 1464 in study 2. Attitudes were of an undifferentiated nature, but respondents did make a major distinction between use for disease prevention and use for enhancement. No strong distinctions were made between embryo selection and germ line gene manipulations, and between somatic gene therapy and germ line gene manipulations. Religiosity was negatively associated with acceptance of "designer baby" technology for Christians and Muslims but not Hindus. However, the strongest and most consistent influence was an apparently moralistic stance against active and aggressive interference with natural processes in general. Trust in individuals and institutions was unrelated to acceptance of the technology, indicating that fear of abuse by irresponsible individuals and corporations is not an important determinant of opposition.

Genetics of the human renin angiotensin system

The genes coding for the renin angiotensin system have been extensively studied. During the last 15 years, informative markers and functional polymorphisms have been identified, and numerous linkage and association studies have been performed in cardiovascular diseases, especially human hypertension. This mini-review aims to summarize the main findings observed for each component of this enzymatic cascade taken alone or in combination, with an emphasis on the most recent or innovative studies.

Evolutionary origins of obesity

Although it appeared relatively suddenly, the current obesity epidemic - largely manifest in industrialized societies but now spreading to the rest of the world - is the result of interaction between human biology and human culture over the long period of human evolution. As mammals and primates, humans have the capacity to store body fat when opportunities to consume excess energy arise. But during the millions of years of human evolution such opportunities were rare and transient. More commonly ancestral hominins and modern humans were confronted with food scarcity and had to engage in high levels of physical activity. In tandem with encephalization, humans evolved elaborate and complex genetic and physiological systems to protect against starvation and defend stored body fat. They also devised technological aids for increasing energy consumption and reducing physical effort. In the last century, industrialization provided access to great quantities of mass-produced, high-calorie foods and many labour-saving and transportation devices, virtually abolishing starvation and heavy manual work. In the modern obesogenic environment, individuals possessing the appropriate combination of ancestral energy-conserving genes are at greater risk for overweight and obesity and associated chronic diseases.

Parallel effects of genetic variation in ACE activity in baboons and humans

Like humans, savannah baboons (Papio sp.) show heritable interindividual variation in complex physiological phenotypes. One prominent example of such variation involves production of the homeostatic regulator protein angiotensin converting enzyme (ACE), which shows heritable variation in both baboons and humans. In humans, this phenotypic variation is associated with an Alu insertion-deletion polymorphism in the ACE gene, which explains approximately half of the variation in serum ACE activity. We identified a similar Alu insertion-deletion polymorphism in the baboon ACE homologue and measured its frequency in a wild population and a captive population of baboons. We also analyzed the contribution of ACE genotype at this indel to variation in serum ACE activity in the captive population. When conditioned on weight, a known factor affecting ACE activity in humans, age and ACE genotype both accounted for variance in ACE activity; in particular, we identified a significant nonadditive interaction between age and genotype. A model incorporating this interaction effect explained 21.6% of the variation in residual serum ACE activity. Individuals homozygous for the deletion mutation exhibited significantly higher levels of ACE activity than insertion-deletion heterozygotes at younger ages (10-14 years), but showed a trend towards lower levels of ACE activity compared with heterozygotes at older ages (> or =15 years). These results demonstrate an interesting parallel between the genetic architecture underlying ACE variation in humans and baboons, suggesting that further attention should be paid in humans to the relationship between ACE genetic variation and aging.

Exercise participation and self-rated health: do common genes explain the association?

The purpose of this study is to investigate whether there is an association between exercise participation and self-rated health and whether this association can be explained by common genes and/or common environmental influences. In a sample of 5,140 Dutch adult twins and their non-twin siblings from 2,831 families, exercise participation (sedentaries, light or moderate, vigorous exercisers) and self-rated health were assessed by survey. To investigate the etiology of the association, bivariate genetic models using structural equation modeling were applied to the data. The correlation between exercise participation and self-rated health is significant but modest (r = 0.20). Exercise participation and self-rated health are both heritable (around 50% of the variance of both phenotypes is explained by genetic factors). The genetic factors influencing exercise participation and self-rated health partially overlap (r = 0.36) and this overlap fully explains their phenotypic correlation. We conclude that the association between exercise and self-rated health can be explained by genes predisposing to both exercise participation and self-rated health. These genes may directly influence both phenotypes (pleiotropy). Alternatively, genes that affect exercise or self-rated health may indirectly influence the other phenotype through a causal relationship. We propose that identification of the genes that cause differences in exercise behavior will help resolve the issue of causality.

Association analysis of the ACTN3 R577X polymorphism and complex quantitative body composition and performance phenotypes in adolescent Greeks

The functional allele (577R) of ACTN3, which encodes human alpha-actinin-3, has been reported to be associated with elite athletic status and with response to resistance training, while the nonfunctional allele (577X) has been proposed as a candidate metabolically thrifty allele. In a study of 992 adolescent Greeks, we show that there is a significant association (P=0.003) between the ACTN3 R577X polymorphism and 40 m sprint time in males that accounts for 2.3% of phenotypic variance, with the 577R allele contributing to faster times in an additive manner. The R577X polymorphism is not associated with other power phenotypes related to 40 m sprint, nor with an endurance phenotype. Furthermore, the polymorphism is not associated with obesity-related phenotypes in our population, suggesting that the 577X allele is not a thrifty allele, and thus the persistence of this null allele must be explained in other terms.