RR Genotype Research Articles

Polymorphism (353)R>Q of gene of blood clotting factor VII and plasma hemostasis

A comparative estimation was conducted to assess the prevalence of genotypes and alleles of the (353)R>Q polymorphism of the coagulation factor FVII gene between a group of the Russian adolescents with essential arterial hypertension and a group of Russian adolescents without such health problems. The RR genotype was diagnosed in 55 adolescents (75.34%) of the control group and in 99 adolescents (84.61%) of the adolescents suffering from essential arterial hypertension (χ2 = 1.949, p = 0.163). The frequency of the R-allel was 85% and 91.9%, respectively (χ2 = 3.110, p = 0.078). The role of the FVII gene in the determination of the F7 plasma activity was defined in adolescents with essential arterial hypertension and holders of different alleles. Holders of the R allele had significantly higher activity of coagulation factor F7 (97.66 ± 15.48 against 83.37 ± 15.16, p = 0.002) and factor F2 (107.45 ± 6.03 against 103.75 ± 6.81, p = 0.023) than holders of the Q allele. This relationship was not found in adolescents of the control group.

Correlation Between ABCA1 Gene Polymorphism and aopA-I and HDL-C in Abdominal Aortic Aneurysm.

BackgroundAs the most common type of aneurysm, abdominal aortic aneurysm (AAA) has an unfavorable prognosis due to the high frequency of rupture. Studies have indicated a close relationship between the pathogenesis and progression of AAA and abnormal serum lipid levels. ATP-binding cassette transport protein A1 (ABCA1) is a cell-surface protein facilitating cellular efflux of cholesterol. The single-nucleotide polymorphism (SNP) of ABCA1 gene has been suggested to be correlated with abnormal metabolism of lipids. Therefore, this study aimed to investigate the relationship between ABCA1 polymorphism and apoA-I and HDL-C in an attempt to elucidate its correlation with AAA occurrence.Material/MethodsWe included 126 AAA patients and 119 healthy controls in this study. PCR and restriction fragment length polymorphism (RFLP) were used to detect the SNP pattern of ABCA1 gene at locus rs2230806 from both AAA patients and healthy controls. The distribution pattern and correlation with apoA-I and HDL-C was analyzed.ResultsThe distribution of KK/RR genotype of ABCA1 gene had significant difference between disease and control group, with lower rates of RR genotype and R allele in the disease group (p<0.05). Levels of apoA-I and HDL-C, but not triglyceride and LDL-C levels, in AAA patients who carried R allele in ABCA1 gene (including RR and RK genotypes) were higher than in non-carriers (p<0.05). The R allele of ABCA1 gene was shown to be related with the occurrence of AAA (p<0.05).ConclusionsPolymorphism of ABCA1 gene is correlated with AAA occurrence, possibly via the regulation of serum lipid metabolism by R allele.

Role of interleukin-4 genetic polymorphisms and environmental factors in the risk of asthma in children.

Asthma is an allergic disease characterized by hyperresponsiveness and chronic inflammation of the airway. The interleukin-4 (IL-4) gene and its single nucleotide polymorphisms are associated with asthma susceptibility in children. A case-control study was performed to evaluate the relationship between asthma risk and the IL-4 rs2243250 (589 C/T) and rs2070874 (107 T/C), and IL-4 receptor (IL-4R) rs1801275 (576 Q/R) polymorphisms in 317 childhood asthma patients and 351 healthy children as controls. Polymerase chain reaction amplification and sequencing was performed. The effects of interactions between the genes of interest and environmental factors were also analyzed. IL-4 rs2243250 and rs2070874 allele and genotype frequencies did not significantly differ between the asthma and control groups (P > 0.05), but those of IL-4R rs1801275 did (P < 0.05). The RR genotype and R allele of this IL-4R variant were significantly associated with asthma risk, with odds ratios (ORs; and 95% confidence intervals) of 2.97 (2.08-4.25) and 2.99 (2.32-3.85), respectively. Logistic regression analysis showed that the IL-4R 576 Q/R RR genotype demonstrated a positive interaction with environments associated with smoking or pets in its effect on asthma risk, with ORs of 2.18 (P = 0.02) and 2.29 (P = 0.01), respectively. Our results suggest that the IL-4R rs1801275 polymorphism is associated with childhood asthma, and the RR genotype confers a high risk of developing this condition. This variant exhibited positive interactions with environments in which smoking or pets were present in increasing the risk of childhood asthma.

0184: Genetic association between single nucleotide polymorphisms in the Paraoxonase 1 (PON1) gene and the risk of myocardial infarction in the Tunisian male population

Coronary artery disease (CAD), the leading cause of death worldwide, is a multifactorial disease arising from the complex interplay of genetic and environmental factors. Paraoxonase 1 (PON1) polymorphisms have been implicated as risk factors for CAD, but the results of genetic association studies on the related phenotype of CAD are inconclusive. The aim of the present study was to investigate the association between the PON1 promoter –108 C>T (rs705381) and the coding region Gln192Arg (Q192R, rs662) and Leu55Met (L55M, rs854560) variants with myocardial infarction (MI) in a sample of the Tunisian population. A total of 382 unrelated MI patients and 380 healthy controls were enrolled in this study. Genotyping was performed by the polymerase chain reaction and restriction fragment length polymorphism method (PCRRFLP). The frequencies of the alleles and genotypes between MI patients and controls were compared by the chi-square test. Genotype distribution and allele frequencies of L55M were similar among the control and MI groups. The PON1-Q192R and –108 C>T genotypes exhibited significant differences in allele and genotype frequencies among the MI and control groups. At PON1-192 locus, there were significant differences between patients and controls (p<0.05), leading to significant odds ratios for RR genotype (OR=1.89, CI: 1.21 – 2.94) and R allele (OR=1.37, CI: 1.11 – 1.69). Binary logistic regression analysis also confirmed that RR genotypes have a higher risk of MI (OR=1.75, CI: 1.03 – 2.98). The T allele of –108C>T polymorphism was found to be a risk marker for MI (OR=1.29, CI: 1.05 – 1.58; p=0.011). The present study showed a significant and independent association between the PON1 Q192R and – 108 C>T polymorphisms and MI in the Tunisian male population.

Association of ACTN3 polymorphisms with BMD, and physical fitness of elderly women.

[Purpose] Association of ACTN3 polymorphism with bone mineral density and the physical fitness of elderly women is still unclear. Therefore, this study investigated the association between ACTN3 genotype and bone mineral density, and the physical fitness of elderly women. [Subjects and Methods] Sixty-eight elderly women (67.38 ± 3.68 years) were recruited at a Seongbuk-Gu (Seoul, Korea) Medical Service Public Health Center. Measurements of physical fitness included muscle strength, muscle endurance, flexibility, agility, balance and VO2max. Bone mineral density (BMD), upper limb muscle mass, lower limb muscle mass, percent body fat and body fat mass for the entire body were measured by dual-energy X-ray absorptiometry and an analyzer. Genotyping for the ACTN3 R577X (rs1815739) polymorphism was performed using the TaqMan approach. [Results] ACTN3 gene distribution of subjects were in the Hardy-Weinberg equilibrium (p=0.694). The relative bone mineral density trunk, pelvis and spine differed significantly among the ACTN3 genotypes. There were no significant differences among bone mineral densities of the head, arms, legs, ribs and total, but the RR genotype tended to be higher than other genotypes. Physical fitness was not significantly different among the ACTN3 genotypes. [Conclusion] These results suggest that ACTN3 gene polymorphisms could be used as one of the genetic determinants of bone mass in elderly women, and in particular, they indicate that individuals with the RR genotype have higher BMD and bone mineral composition.

Effects of Paraoxonase 1 gene polymorphisms on organophosphate insecticide metabolism in Japanese pest control workers.

Paraoxonase 1 (PON1) in serum detoxifies organophosphate (OP) insecticides by hydrolysis. The present cross-sectional study aimed to clarify the relationship between PON1 single nucleotide polymorphisms (SNPs) and enzyme activities or OP metabolite concentrations in urine of workers occupationally exposed to low-level OPs. Among 283 workers in 10 pest control companies located in central Japan who underwent checkups, 230 subjects (male 199, female 31, average age 38.9 ± 11.1 years old) participated in the study. Q192R and L55M polymorphisms were determined by TaqMan assay. PON1 activity was measured using fenitrothion (FNT) oxon, chlorpyrifos-methyl (CPM) oxon, chlorpyrifos (CP) oxon, and phenyl acetate as substrates. Urinary OP metabolite concentrations were measured with gas chromatography-mass spectrometry. The maximum differences in enzyme activities between individuals were 64.6-, 6.3-, 7.7-, and 2.0-fold for FNT oxonase, CPM oxonase, CP oxonase, and arylesterase (ARE), respectively. The activities of CPM oxonase and ARE in workers having the RR genotype were 53.5% and 18.2% lower than in those with the QQ genotype, respectively. CP oxonase activity was 15.0% lower in those having the M allele (LM + MM compared with LL). Urinary metabolite concentrations were not associated with PON1 polymorphisms, but negative associations were observed between the concentrations and activities of FNT oxonase and ARE. While PON1 SNPs can explain differences in catalytic activities toward some OPs, differences in urinary concentrations of OP metabolites are not attributable to PON1 SNPs but instead are attributable to its serum activities. Its serum activities might be more sensitive biomarkers for estimation of individual susceptibility to OP toxicities.

Genetic association between ACTN3 polymorphism and risk of non-acute ankle sprain.

In this study, we investigated the association between ACTN3 R577X polymorphism and non-acute ankle sprain by measuring the allele frequency and genotype distribution of ACTN3 in a Chinese Han population. We recruited 100 patients with non-acute ankle sprain and 100 healthy controls with no history of ankle injuries. Mass spectrometric analysis of single nucleotide polymorphism was used to analyze the genotype and allele frequencies of ACTN3. Results showed that the genotype frequency of RR in patients was 12.0%, which was significantly lower than that of the controls (24.0%) (OR = 1.7; 95%CI = 1.5-2.7; P = 0.001). The frequency distribution of the R allele in patients and controls were 68.5 and 56.7%, respectively (P = 0.002). Moreover, frequency of the RR genotype exhibited a downward linear trend with increased incidences of ankle sprain. Our results suggest that ACTN3 R577X polymorphism is associated with non-acute ankle sprain in the Chinese Han population.

Genetic polymorphisms in alpha-actinin 3 and ­adrenoceptor beta genes in Austrian elite athletes and healthy controls

Background: During the last years many studies were conducted to investigate the contribution of various genetic variants to endurance and sprint/power performance of elite athletes. Data on team sport athletes are missing to a large extent. Therefore, the aim of the study was to investigate the frequency of selected polymorphisms on elite athlete status in Austrian team sport (handball, soccer), endurance and power athletes as well as in healthy control subjects. Methods: Genotype and allele frequencies of ACTN3 R577X (rs1815739), ADRB1 Ser49Gly (rs1801252), ADRB2 Arg16Gly (rs1042713), ADRB2 Gln27Glu (rs1042714) and the ADRB3 Trp64Arg (rs4994) polymorphisms were determined in 56 Austrian sprint/power athletes, 86 endurance athletes, 143 team sport athletes and 216 healthy non-athletic controls. Genomic DNA was extracted from saliva and genotyping was performed by real time polymerase chain reaction using a standard protocol. Results: Handball and soccer players had a higher frequency of the ACTN3 RR genotype and a lower frequency of RX + XX genotypes than the control group. Furthermore, the frequency of athletes being homozygous for the ADRB1 Ser49Ser genotype was significantly higher in team sport athletes in comparison to those competing in power/sprint sports. We did not detect any other differences in genotype distributions between the study groups. Conclusion: This study provides some evidence that the ACTN3 R577X and the ADRB1 Ser49Gly polymorphisms are associated with team sport performance. Larger prospective studies focusing on the genetic influence of performance development are required for confirmation of these findings.

The role of PON1 and CYP2D6 genes in susceptibility to organophosphorus chronic intoxication in Egyptian patients

BackgroundParaoxonase-1 (PON1) activity toward organophosphorus(OP) compounds shows inter-individual variations, rendering the identification of individuals’ PON1 allozymes valuable in treating patients suffering from organophosphorus intoxication. One of the most important cytochrome P450 monooxygenases (CYPs) is CYP2D6. The CYP2D6 G1934A polymorphism leads to good, poor or no enzyme activity. Genetic testing helps identification of high risk individuals as well as management of chronic intoxicated patients. Objectiveto investigate a possible association between genetic polymorphisms of PON1 Q192R, and CYP2D6 G1934A as well as PON1 and pseudo-cholinesterase (PChE) enzyme activity levels and chronic organophosphate exposed patients, and hence, susceptibility for organophosphorus chronic poisoning. Design and methodsThirty chronic organophosphate exposed farm workers were compared to 29 healthy controls as regards PON1 Q192R and CYP2D6 G1934A polymorphisms using PCR-RFLP technique. Also serum PON1 and PChE activities were determined spectrophotometrically. ResultsSerum PChE was significantly reduced in chronic intoxicated patients compared to the control group (p=0.02), while PON1 activity was increased, but just failed to reach significance (p=0.06). PON1 192 RR genotype and R allele were significantly increased in chronic OP intoxicated patients (p=0.005 &p=0.002 respectively). CYP2D6 1934A allele was significantly increased in chronic OP patients (p=0.045). combining the two SNPs showed a significant statistical difference between the two groups with PON1QQ and CYP2D6 GG genotypes being more represented in the healthy controls (p=0.001). Fatigue and motor weakness were the most prevalent neurological symptoms seen in chronic cases (56.7%), followed by headache and lacrimation (30% each), depression (23%), tingling and sensory symptoms (20%), sleep disorders and limb pain (13%).The mean duration of environmental exposure to organophosphates was 7.7±5.2years and no association was found between chronic symptoms of intoxication and duration of exposure, provided that all workers were exposed for at least 3 years. ConclusionPON1 192RR genotype and CYP2D6 1934A allele were found to be related to the susceptibility to organophosphate chronic toxicity in Egyptians. Larger scale gene-environmental interaction studies are recommended to confirm results and Genotyping is recommended during selection of agricultural pesticide workers to exclude high risk group.

Association of angiotensin-converting enzyme I/D and α-actinin-3 R577X genotypes with metabolic syndrome risk factors in Korean children

This study analysed the risk factors associated with metabolic syndrome through the interaction between ACTN3 and ACE gene polymorphism in Korean children. The subjects of the study consisted of elementary school students (n=788, age 10.10±0.07 yr). The anthropometric parameters, blood lipid profiles, and metabolic markers were compared among groups of the ACE I/D or the ACTN3 R577X polymorphisms. The subjects with the DD genotype showed significantly higher systolic blood pressure than the subjects with the II and ID genotype of the ACE gene polymorphism. XX genotype had significantly lower waist-hip ratio than those with RR genotype of the ACTN3 gene polymorphism. Also, the subjects with XX genotype exhibited significantly higher blood HDL cholesterol level than those with RR or RX genotype. The interaction of ACTN3 and ACE gene polymorphism in subjects having both ACE DD and ACTN3 RR genotypes demonstrated a significantly higher metabolic syndrome score than any other groups. The children having both ACTN3 RR or RX genotype and ACE DD genotype showed high systolic blood pressure and low blood HDL cholesterol level, which may be considered a high-risk in metabolic syndrome.

Paraoxonase 1 and cytochrome P450 polymorphisms in susceptibility to acute organophosphorus poisoning in Egyptians

BackgroundOrganophosphates are the basis of many insecticides, herbicides, and nerve agents. They were listed as highly acutely toxic agents. Findings in knockout mice suggest that paraoxonase 1 may modulate the toxicity resulting from exposure to organophosphorus compounds. In human, there is no enough data about genetic modulation of acute organophosphorus intoxication. CYP2D6 is involved in the metabolism of about 30% of xenobiotics. Prompt accurate management of OP acute intoxication can promote patient's survival. Design and methodsForty acute organophosphorus intoxicated patients were divided according to presence of clinical toxicity manifestations and serum level of pseudo-cholinesterase into two groups of acute symptomatic and acute asymptomatic patients. A third group of 29 healthy volunteers served as control. Paraoxonase 1 Q192R and CYP2D6 G1934A polymorphisms, (QQ, QR, and RR for PON1) and (GG, GA, and AA for CYP2D6), were studied using polymerase chain reaction-restriction fragment length polymorphism technique. Serum paraoxonase 1 and pseudo-cholinesterase activities were measured spectrophotometrically. ResultsSerum pseudo-cholinesterase was significantly reduced in both acute intoxication groups compared to the controls (p=0.000). Paraoxonase 1 was significantly reduced in the symptomatic acute intoxication patients in comparison to the asymptomatic group (p=0.002). There was a significant increase in paraoxonase 1 192 RR genotype and R allele in the symptomatic patients in comparison to the controls and asymptomatic patients (p=0.006 and p=0.01, respectively). For CYP2D6 G1934A genotypes and alleles, no significant difference was found between groups (p=0.3 and p=0.18, respectively). However, one case of the two recorded fatalities was for a symptomatic female patient with the only traced AA genotype. The combination of both single nucleotide polymorphisms revealed a significant distribution difference between groups, with QQ+GG genotypes being more represented in the controls, while RR+GA genotypes were exclusively present in the group of symptomatic patients (p=0.04), none of the participants was found to have RR+AA genotypes.Some nicotinic (fasciculation and weakness), and muscarinic symptoms (bronchospasm, salivation, lacrimation, and diarrhea), increased with high significance in the symptomatic group compared to the asymptomatic one (p<0.001 for all). Convulsions also showed significant increase (p=0.02). ConclusionParaoxonase 1 Q192R modulates patient's response, and CYP2D6 may be related to the acute organophosphorus intoxication in the context of other genetic-environmental factors. Paraoxonase 1 enzyme level is related to symptom severity in acute OP poisoning, while pseudo-cholinesterase level indicates exposure to OP rather than severity of clinical manifestations.

Oxidative stress biomarkers and paraoxonase 1 polymorphism frequency in farmers occupationally exposed to pesticides.

Previous evidence has demonstrated that chemical classes of pesticides, including organophosphates (OP), can induce oxidative stress in exposed workers. The resulting increase in free radicals causes damage to biological macromolecules, and promotes the formation of novel compounds, including advanced glycation end products (AGE) and advanced oxidation protein products (AOPP). The present study aimed to evaluate the common genetic polymorphisms of the paraoxonase 1 (PON1) gene in a group of 55 farmers exposed to pesticides, as well as the association between these polymorphisms and serum levels of AGE and AOPP. The 192Q wild‑type (WT) allele was present at a significantly higher frequency, compared with the 192R mutated allele (0.74 and 0.26, respectively). The WT allele was predominantly represented by the homozygote 192QQ genotype (51%). The mutated 192QR heterozygotic allele was prevalent, at a frequency of 45.4%, whereas the mutated homozygotes were present at a frequency of 3.6%. A significant decrease in the levels of AGE and AOPP was observed in farmers exhibiting the homozygotic 192RR mutated genotype (14,7221 AU/ml and 0.64 nmol/ml, respectively), compared with the WT genotype (16,1400 AU/ml and 1.76 nmol/ml, respectively), and 192QR genotype (15,2312 AU/ml and 1.60 nmol/ml, respectively). Therefore, due to the high catalytic activity of PON1, the 192RR genotype provides an important genetic predictor of the toxic effects associated with OP pesticide exposure. It determines a minor risk of developing oxidative damage following pesticide exposure, and measuring the levels of AOPP may provide a novel biomarker for oxidative damage in subjects exposed to OP.

Association between Paraoxonase 1 (PON1) Polymorphisms and the Risk of Acute Coronary Syndrome in a North African Population.

The purpose of the present study was to investigate the distribution of PON1 Q192R and L55M polymorphisms and activities in a North African population and to determine their association with cardiovascular complications. The prevalence of the QQ, QR, RR, LL, LM, and MM genotypes in the study population was 55.4%, 34.09%, 9.83%, 41.97%, 48.20%, and 9.83% respectively. The Q, R, L, and M alleles had a gene frequency of 0.755, 0.245, 0.67, and 0.33, respectively. The PON1 192 RR genotype was significantly more prevalent among ACS patients than among healthy subjects. There was a 4.33-fold increase in the risk of ACS in subjects presenting the PON1 192 RR genotype compared to those with the QQ genotype (OR=4.33; 95% CI=1.27–17.7). There was a significantly different distribution of PON1 L55M in the ACS patient groups (UA, STEMI, NSTEMI). Moreover, individuals presenting the PON1 55MM genotype present a higher risk for ACS than those with LL genotype (OR=3.69; 95% CI=1.61–11.80). Paraoxonase activities were significantly lower in coronary patients than in healthy subjects. The decrease in PON1 activity was inversely correlated with the number of concomitant risk factors for CVD (r=0.57, p<0.0001). The results of the present study suggested that the PON1 R and M alleles may play a role in the pathogenesis of cardiac ischemia in our North African population and that a decrease in PON1 activity may be a valuable marker for monitoring the development of the atherosclerosis process and the associated cardiovascular complications.

Relationship Between ACTN3 R577X Polymorphism and Physical Abilities in Polish Athletes.

The purpose of this study was to examine the association between α-actinin 3 (ACTN3) R577X polymorphism and physical abilities of male athletes performing various sports (volleyball, ice hockey, canoeing, swimming). One hundred eighty-five subjects were recruited for the study. The following measurements were taken: height of jump and power output in countermovement jump and spike jump (SPJ) and muscle strength of 10 muscle groups. The R577X polymorphism of ACTN3 was typed using polymerase chain reaction restriction fragment length polymorphism. The results showed that RR genotype carriers develop greater power output in SPJ than RX and XX individuals (44.6 ± 11.1, 42.6 ± 11.0, and 38.4 ± 7.9 W·kg(-1) for RR, RX, and XX genotypes, respectively) and height of jump in SPJ (0.537 ± 0.075, 0.523 ± 0.072, and 0.498 ± 0.053 m for RR, RX, and XX genotypes, respectively). Muscle strength did not differ between genotype groups. This suggests that the ACTN3 gene has a greater impact on determining dynamic movements than influencing static muscle strength.

Post-zygotic selection against parental genotypes during larval development maintains all-hybrid populations of the frog Pelophylax esculentus.

BackgroundHybridization between two species usually leads to inviable or infertile offspring, due to endogenous or exogenous selection pressures. Yet, hybrid taxa are found in several plant and animal genera, and some of these hybrid taxa are ecologically and evolutionarily very successful. One example of such a successful hybrid is the water frog, Pelophylax esculentus which originated from matings between the two species P. ridibundus (genotype RR) and P. lessonae (LL). At the northern border of the distribution all-hybrid populations consisting of diploid (LR) and one or two triploid (LLR, LRR) frog types have been established. Here, the hybrid has achieved reproductive independence from its sexual ancestors and forms a self-sustaining evolutionary unit. Based on the gamete production of these hybrids, certain mating combinations should lead to LL and RR offspring, but these parental forms are absent among the adults.ResultsIn order to investigate the mechanisms that maintain such an all-hybrid system, we performed a field study and a crossing experiment. In the field we sampled several ponds for water frog larvae at different developmental stages. Genotype compositions were then analysed and life-history differences between the genotypes examined. In the experiment we crossed diploid and triploid males and females from different ponds and determined fertilization success as well as development speed and survival rates of the offspring under high, medium and low food availability. In both parts of the study, we found numerous LL and RR offspring during the egg and early larval stages; but the frequency of these parental genotypes decreased drastically during later stages. In natural ponds almost all of them had disappeared already before metamorphosis; under the more benign experimental conditions the last ones died as juveniles during the following year.ConclusionsFrom the combined results we conclude that the absence of parental genotypes in all-hybrid populations is due to post-zygotic selection against them, rather than to pre-zygotic mechanisms that might prevent their formation in the first place. For this post-zygotic selection, genetic mechanisms resulting from low genetic diversity and fixation of deleterious mutations seem to be a more likely explanation than ecological factors.

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

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

ACTN3 Polymorphism: Comparison Between Elite Swimmers and Runners.

BackgroundThe human ACTN3 gene encodes α-actinin-3, an actin-binding protein with a pivotal role in muscle structure and metabolism. A common genetic single nucleotide polymorphism (SNP) at codon 577 of the ACTN3 results in the replacement of an arginine (R) with a stop codon (X). The R allele is a normal functional version of the gene, whereas the X allele contains a sequence change that completely stops production of functional α-actinin-3 protein. The ACTN3 R577X polymorphism was found to be associated with power athletic performance especially among track and field athletes. The aim of the current study was to compare allelic and genotype frequencies of the ACTN3 R577X polymorphism among runners and swimmers specializing in different distances, and >non-athletic controls.MethodsOne hundred and thirty-seven runners, 91 swimmers and 217 controls, participated in the study. Runners were assigned to two subgroups according to their event specialty—long-distance runners (LDR) and short-distance runners (SDR). Swimmers were also assigned to two subgroups according to their main swimming event—long-distance swimmers (LDS) and short-distance swimmers (SDS). Genomic DNA was extracted from peripheral EDTA-treated anti-coagulated blood using a standard protocol. Genotypes were determined using the Taqman allelic discrimination assay.ResultsRunners’ genotype and allele differed significantly between LDR, SDR, and controls, with the lowest prevalence of RR genotype and R allele among LDR. XX genotype and X allele prevalence was significantly higher among LDR compared to the other groups (p < 0.01 for all). On the other hand, swimmers’ genotype and allele frequencies did not differ significantly between subgroups (LDS and SDS). Yet, LDS had significantly higher RR genotype and R allele frequencies compared to LDR.ConclusionsThe findings suggest that while ACTN3 R577X polymorphism is a genetic polymorphism that may distinguish between SDR and LDR, it cannot differentiate significantly between SDS and LDS.Trial RegistrationClinicalTrials.gov: NCT01319032Key PointsACTN3 R577X polymorphism is largely associated with running events specialization, with high prevalence of RR genotype and R allele frequency among short-distance runners compare to long-distance runners.Unlike in running, ACTN3 R577X polymorphism is not associated with swimming specialization.The inability of the ACTN3 R577X polymorphism to distinguish between swimmers specializing in different events, presumably since other factors such as body physique, technique, tactics, etc., are more likely to determine such a distinction.

Influence of ACTN3 R577X polymorphism on ventilatory thresholds related to endurance performance

The purpose of this study was to verify the association between ACTN3 polymorphism and physiological parameters related to endurance performance. A total of 150 healthy male volunteers performed a maximal incremental running test to determine the speeds corresponding to ventilatory threshold (VT) and respiratory compensation point (RCP). Participants were genotyped and divided into terciles based on the analysed variables. Genotype frequencies were compared through χ2 test between lower and higher terciles, with the lowest or highest values of each analysed variable. ACTN3 XX genotype was over-represented in higher tercile for VT and RCP. Odds ratio also showed significantly higher chances of XX individuals to be in higher tercile compared to RR (7.3) and RR + RX (3.5) for VT and compared to RR genotype (8.1) and RR + RX (3.4) for RCP. Thus, XX individuals could attain the VT and RCP at higher speeds, suggesting that they are able to sustain higher running speeds in lower exercise intensity domains. It could result in higher lipid acids oxidation, saving muscle glycogen and delaying the fatigue during prolonged exercises, which could be the advantage mechanism of this genotype to endurance performance.

ACE and ACTN3 Genes Polymorphisms and Endurance Performance

ACE I/D and ACTN3 R577X polymorphisms are the most extensively studied genes in recent years in association with human physical performance. VO2max is recognized as one of the major quantitative traits in sports physiology and the most common method to demonstrate cardiorespiratory endurance. The heritability for the VO2max in several studies has been observed up to 51%. PURPOSE: (1) To assess ACE gene ACTN3 genotype frequencies in young male skiers compared to the control group and (2) to analyze the relationships between VO2peak and ACE I/D and ACTN3 R577X polymorphisms in young male skiers. METHODS: Male skiers (n=56; 14 to 21 yrs), 52% of them are current or former junior national team members of Estonia. A standardized exercise test on a treadmill with determination VO2peak was performed. Anthropometric measurements and training characteristics were obtained. The male control group (n=145, 20 to 37 yrs) consisted of healthy sedentary subjects without previous athletic status. Venous blood samples for DNA extraction were collected. Genotyping of rs4343 (ACE, C_11942562_20) and rs1815739 (ACTN3, C_590093_1) was carried out by using the TaqMan SNP 5’ allelic discrimination assay. For statistical analysis, descriptive analysis, χ2-test was used. RESULTS: Frequency of ACE ID and ACTN3 RR genotypes in male skiers was statistically higher (p<0.05) and frequency of RX genotype of ACTN3 was lower (p<0.05) compared with controls. There were no significant differences in distribution of ACE I/D and ACTN3 R577X polymorphisms between the groups with different competing levels. We did not observe significant differences in mean VO2peak between ACE I/D, as well between ACTN3 R577X genotypes in male skiers. CONCLUSIONS: Our study results revealed a statistically higher prevalence of ACE ID and ACTN3 RR genotypes in young male skiers (64% and 40%, respectively) compared with male controls (47% and 18%, respectively). Mean VO2peak did not show significant differences between ACE I/D as well between ACTN3 R577X genotypes in male young skiers.

Contrasting genetic influence of PON 1 coding gene polymorphisms L55M and Q192R on individuals’ response to environmental agents

BackgroundParaoxonase (PON1) is an A-esterase capable of hydrolyzing the active metabolites (oxons) of many organophosphorus (OP) insecticides. Human PON1 displays two polymorphisms in the coding region (Q192R and L55M) and several polymorphisms in the promoter and the 3′-UTR regions. Animal studies have shown that PON1 is an important determinant of OP toxicity though a direct satisfactory verification in humans is still lacking. AimTo investigate the impact of polymorphisms in the PON1 coding region (Q192R and L55M) on individual sensitivity to OP poisoning. Subjects and methodsThis study enrolled 42 subjects (21 females and 21 males, age range 1.5–53years) diagnosed of acute OP poisoning. They were classified into 4 grades according to manifestations. All subjects were genotyped for the PON1 gene polymorphisms; Q192R and L55M using RFLP-PCR, then genotype frequencies were compared between different OP grades. ResultsGenotype frequency distribution of PON1 L55M polymorphism among different OP poisoning grades revealed no significant difference (p>0.05) between the four grades. In contrast, frequency distribution of PON1 Q192R polymorphism showed a highly significant (p<0.001) difference between different grades of OP poisoning, with QQ genotype predominating in grade 4 with a frequency of 66.7%, followed by QR genotype (33.3%), while the RR and QR genotypes were similarly distributed in grade 1 with a frequency of 50% for each. ConclusionThe current results suggest a possible association between QQ genotype and poor OP poisoning prognosis.