Reaction-restriction Fragment Length Polymorphism Research Articles

Interaction of the CYP1A1 gene polymorphism and smoking in non-small cell lung cancer susceptibility

Many studies have shown that genetic factors, environmental factors, and bad living habits, especially smoking, are risk factors for lung cancer. However, not all smokers develop lung cancer, which may be related to different genetic backgrounds. Currently, most research has investigated the GSTM1, XRCC1, XRCC3, CYP2D6, and C188T genes. Little research has been done on the cytochrome P450 (CYP) 1A1 gene, and results have varied. In addition, no results have been reported on the interactive effects of smoking and the CYP1A1 gene on lung cancer development. We used polymerase chain reaction restriction fragment length polymorphism to detect the CYP1A1 genotype, and investigate the effects of the CYP1A1 gene deletion and smoking alone, and in combination, on non-small cell lung cancer susceptibility. We enrolled 150 non-small cell lung cancer patients and 150 healthy control subjects. Subjects' smoking habits and CYP1A1 gene polymorphism were analyzed to investigate their role in the occurrence of lung cancer. The CYP1A1 gene deletion was found in 73.3% of non-small cell lung cancer patients and 20.0% of healthy subjects. The OR value was 2.28 (P < 0.05). Among smoking subjects, 77.8% exhibited non-small cell lung cancer, significantly higher than the 27.3% in non-smokers (P < 0.05). The OR value for the interaction of smoking and CYP1A1 gene deletion was 5.60, larger than the product of their individual OR values. The CYP1A1 gene deletion is a lung cancer risk factor, and interacts with smoking in non-small cell lung cancer development.

A STAT6 Intronic Single-Nucleotide Polymorphism is Associated with Clinical Malaria in Ghanaian Children.

Malaria pathogenesis may be influenced by IgE responses and cytokine cross-regulation. Several mutations in the IL-4/STAT6 signaling pathway can alter cytokine cross-regulation and IgE responses during a Plasmodium falciparum malarial infection. This study investigated the relationship between a STAT6 intronic single-nucleotide polymorphism (rs3024974), total IgE, cytokines, and malaria severity in 238 Ghanaian children aged between 0.5 and 13 years. Total IgE and cytokine levels were measured by ELISA, while genotyping was done by polymerase chain reaction-restriction fragment length polymorphism (RFLP). Compared with healthy controls, heterozygosity protected against clinical malaria: uncomplicated malaria (odds ratios [OR] = 0.13, P < 0.001), severe malarial anemia (OR = 0.18, P < 0.001), and cerebral malaria (OR = 0.39, P = 0.022). Levels of total IgE significantly differed among malaria phenotypes (P = 0.044) and rs3024974 genotypes (P = 0.037). Neither cytokine levels nor IL-6/IL-10 ratios were associated with malaria phenotypes or rs3024974 genotypes. This study suggests a role for rs3024974 in malaria pathogenesis and offers further insights into an IL-4/STAT6 pathway mutation in malaria pathogenesis.

The C161T Polymorphism in Peroxisome Proliferator-Activated Receptor &amp;lt;i&amp;gt;&amp;amp;#611;&amp;lt;/i&amp;gt;2, but Not Pro12Ala, Is Associated with Diabetic Retinopathy in Type 2 Diabetes Mellitus in an Egyptian Population

Objectives: Diabetic retinopathy (DR) is one of the most common microvascular complications of type 2 diabetes mellitus (T2DM). It is multifactorial with the contribution of multiple genetic factors. We questioned the association of polymorphisms in the peroxisome proliferator-activated receptor ?2 (PPAR?2) gene (Pro12Ala and C161T) with DR in an Egyptian population. Methods: This case control study included one hundred healthy individuals and 252 T2DM among them 122 with DR and 130 without DR. Genotyping was done by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Results: The Pro12Ala Ala allele was associated with decreased risk of DR with an odds ratio (OR) of 0.484, 95% confidence interval (CI) (0.254 - 0.920), and a p value = 0.024. The C161T T allele was associated with increased risk of DR with OR = 2.593, 95% CI (1.672 - 4.020), p 1c) in multivariate regression analysis only C161T was associated with increased risk of DR with OR = 3.479, 95% CI (1.907 - 6.346), p 1c was higher in Pro/Pro genotype when compared to those with Ala/Ala and Pro/Ala genotypes. Conclusion: We report that T allele of C161T increased risk of DR in the studied population. Further studies are warranted to investigate functional implications of polymorphisms of the PPAR-? gene in DR development.

Association analysis of TOR1A polymorphisms rs2296793 and rs3842225 in a Chinese population with cervical dystonia

BackgroundTOR1A (torsinA, DYT1) is the leading cause of early-onset generalized dystonia, however, the associations between common TOR1A single nucleotide polymorphisms (SNPs) and primary adult-onset focal dystonia are controversial. MethodsIn a cohort of 201 focal cervical dystonia (CD) patients, we genotyped rs2296793 and rs3842225 SNPs in TOR1A using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. We also included 289 unrelated, age- and sex-matched healthy controls (HCs) from the same region. ResultNo significant differences were found in either the genotype distributions or minor allele frequencies (MAFs) of rs2296793 and rs3842225 between CD patients and HCs. There were no significant differences between early-onset and late-onset CD patients, between patients with and without a positive family history of dystonia, or between patients with and without tremor or sensory tricks. ConclusionOur study suggests that the common rs2296793 and rs3842225 SNPs of TOR1A do not play a major role in CD in a Chinese population.

Breast cancer risk in relation to TP53 codon 72 and CDH1 gene polymorphisms in the Bangladeshi women.

Pharmacogenomic studies play a significant role in understanding the risk of breast cancer where genetic abnormalities are implicated as the etiology of cancer. Various polymorphisms of tumor suppressor gene TP53 and E-cadherin (CDH1) have been found to be associated with increased breast cancer risk worldwide. This study aimed to analyze the contribution of TP53 and CDH1 gene anomalies in breast cancer risk in the Bangladeshi breast cancer patients. For risk determination, 310 patients with breast cancer and 250 controls from Bangladeshi women were recruited who are matched up with age and use of contraceptives with patients. Genetic polymorphisms were detected by using polymerase chain reaction restriction fragment length polymorphism. A significant association was found between TP53Arg72Pro (rs1042522) and CDH1 -160 C/A (rs16260) polymorphisms and breast cancer risk. In case of P53rs1042522 polymorphism, Arg/Pro (P = 0.0053, odds ratio (OR) = 1.69) and Pro/Pro (P = 0.018, OR = 1.83) genotypes were associated with increased risk of breast cancer in comparison to the Arg/Arg genotype. Arg/Pro + Pro/Pro genotype and Pro allele also increased the risk of breast cancer (P = 0.002, OR = 1.73; P = 0.004, OR = 1.43, respectively). In case of CDH1rs16260 polymorphism, C/A heterozygote and combined C/A + A/A genotypes were found to be strongly associated (P = 0.005, OR = 1.67; P = 0.0037, OR = 1.68) with increased risk of breast cancer. The variant A allele also increased the breast cancer risk (P = 0.0058, OR = 1.52). The present study demonstrates that P53Arg72Pro and CDH1rs16260 polymorphisms are associated with elevated breast cancer risk in the Bangladeshi population.

Genetic variations in interleukin-12B in allergic rhinitis.

Interleukin (IL)-12B is a key regulator in the protection against allergic reaction induced by various allergens in patients with allergic rhinitis (AR). This study was performed to investigate the associations between single nucleotide polymorphisms in the IL-12B gene and AR in a Chinese Han population. A total of 543 patients with AR and 600 healthy controls were genotyped for IL-12B/rs6887695, rs10045431, rs3212227, rs3212217, and rs2082412 using polymerase chain reaction (PCR) restriction fragment length polymorphism and PCR direct sequencing. The expression of IL-12B mRNA in peripheral blood mononuclear cells (PBMCs) obtained from normal controls was detected by quantitative real-time PCR. Levels of interferon (IFN)-γ and IL-4 in culture supernatants were measured by enzyme-linked immunosorbent assay. The frequencies of the rs3212227 genotype with the CC and C alleles were higher in patients with AR (p c = 8.55 × 10(-4); p c = 4.20 × 10(-4), respectively) than in normal controls. After peptidoglycan stimulation in PBMCs, IL-12 mRNA expression was reduced in healthy carriers of the CC genotype of rs3212227. Additionally, decreased production of IFN-γ was observed in patients having the CC genotype as compared with that in patients having the AC and AA genotypes. In contrast, IL-4 expression was higher in patients with the CC genotype than in patients with the other two genotypes. The IL-12B gene was involved in mediating susceptibility to AR.

Apolipoprotein E Gene Polymorphisms in Essential Hypertension: A Preliminary Study with Meta-analysis

Introduction: Essential hypertension is a multifactorial disease. Many experimental studies have elucidated the role of oxidative stress and atherosclerosis in the pathogenesis of essential hypertension. Apolipoprotein E is a plasma protein that is found to have antioxidant properties, and it also protects against atherosclerosis. Interestingly, the biological function of apolipoprotein E is strongly affected by polymorphisms in its gene. Based on this evidence, our aim was to investigate the association of apolipoprotein E gene polymorphisms with essential hypertension. Methods: This study was conducted on 70 hypertensive patients and 73 control participants recruited from the Balok governmental health clinic in Kuantan, Pahang. The polymerase chain reaction restriction fragment length polymorphism assay (PCR-RFLP) was used for determination of the apolipoprotein E genotype. Our results were also verified later by direct sequencing of the amplicons. Results: There was no significant association of apolipoprotein E allele or genotype frequencies with hypertensive disease or blood pressure levels, although the E4 allele was slightly more frequent in the hypertensive patients than in the control group (OR=1.055; 0.471–2.359, CI 95%). To improve the precision of the study and to settle the controversies among similar studies meta-analysis was performed; however it revealed a net nonsignificant association between the apolipoprotein E4 allele with essential hypertension in the combined population. Conclusion: Our data and the meta-analysis findings provide evidence that apolipoprotein E gene polymorphism has no direct significant association with hypertension.

VEGF Gene Polymorphisms are Associated with Risk of Tetralogy of Fallot.

BackgroundThe aim of this study was to investigate associations of 3 common polymorphisms in the VEGF gene, −2578C>A, −634C>G, and 936C>T, with risk of tetralogy of Fallot (TOF) in Chinese Han children.Material/MethodsFrom January 2010 to June 2013, a total of 400 pediatric subjects were recruited, including 160 cases with TOF (TOF group) and 240 healthy controls (control group). The genotypes of 3 common VEGF polymorphisms, −2578C>A, −634C>G, and 936C>T, were analyzed by polymerase chain reaction restriction fragment length polymorphism. All data were analyzed with SPSS 18.0 software.ResultsNo significant differences were observed in body mass index or sex between TOF patients and controls (both P>0.05), but significant differences in age and family history of TOF were observed between the 2 groups (both P<0.05). The AA genotype in -2578C>A of VEGF was correlated with a significantly increased risk of TOF, and TOF risk in A allele carrier was 1.54-fold higher than that of C allele carrier (OR=1.54, 95%CI=1.14–2.09, P=0.005); the statistical significance was still present after Bonferroni correction (Pc=0.045). GG genotype in −634C>G of VEGF gene was also associated with an increased risk of TOF, and TOF risk in patients with G allele was 1.62-fold higher compared to patients with C allele (OR=1.62, 95%CI=1.19–2.21, P=0.002); the statistical significance was still present after Bonferroni correction (Pc=0.018). Interestingly, T allele in VEGF 936C>T polymorphism is associated with a decreased TOF risk (OR=0.65, 95%CI=0.49–0.87, P=0.003, the statistical significance was still present after Bonferroni correction (Pc=0.027). The result of logistic regression analysis revealed that −2578C>A, −634C>G, and 936C>T genotypes are independently related to the prevalence of TOF (all P<0.05).ConclusionsOur results confirmed that VEGF genetic polymorphisms, −2578C>A and −634C>G, may be associated with an increased TOF risk, while 936C>T polymorphism may be associated with decreased TOF risk.

Heat shock protein 70-2 and tumor necrosis factor-α gene polymorphisms in Chinese children with Henoch-Schönlein purpura.

Henoch-Schönlein purpura (HSP) or IgA-associated vasculitis is related to immune disturbances. Polymorphisms of the heat shock protein 70-2 gene (HSP70-2) and the tumor necrosis factor-a gene (TNF-α) are known to be associated with immune diseases. The purpose of this study was to investigate the likely association of HSP70-2 (+1267A/G) and TNF-α (+308A/G) gene polymorphisms with HSP in children. The polymerase chain reaction restriction fragment length polymorphism method was used to detect the HSP70-2 and TNF-α polymorphisms in 205 cases of children with HSP and 53 controls; and the association of these polymorphisms with HSP and HSP nephritis (HSPN) was analyzed. The G/G genotypic frequencies at the +1267A/G position of HSP70-2 in the HSP group (22.9%) were significantly higher than those in the healthy control group (9.4%) (χ(2)=4.764, P<0.05). The frequencies of the A/A, A/G and G/G genotypes of HSP70-2 in patients in the nephritis-free group and the HSPN group showed no statistically significant difference. The A/A genotype frequency at the +308G/A position of TNF-α in the HSP group was 8.3%, which was higher than that in the control group (χ(2)=6.447, P<0.05). The A allele frequency of TNF-α in the HSP group was higher than that in the control group, with a statistically significant difference (χ(2)=7.241, P<0.05). The HSP70-2 (+1267A/G) and TNF-α (+308G/A) gene polymorphisms were associated with HSP in children. The G/G homozygosity of HSP70-2 and the A/A homozygosity of TNF-α may be genetic predisposing factors for HSP.

A genetic study of steroid-resistant nephrotic syndrome: relationship between polymorphism -173 G to C in the MIF gene and serum level MIF in children.

There is no satisfactory explanation as to why some nephrotic syndrome (NS) patients respond to glucocorticoids and others do not. The aim of this study was to investigate an association between single nucleotide polymorphism of the MIF gene -rs755622 and serum MIF concentrations in NS patients. During a period between November 2011 and September 2012, 120 consecutive children divided into three groups [healthy children, steroid-resistant nephrotic syndrome (SRNS) and steroid-sensitive nephrotic syndrome (SSNS)] were examined. Children were defined as healthy when they had a normal estimated glomerular filtration rate and spot urinary albumin creatinine ratio <150 μg/mg creatinine. SRNS was diagnosed in children who did not respond to the usual doses of steroids within 4 weeks of initiating treatment. SSNS patients were defined as those who had remission after usual doses of steroids. The genotype of -173 G to C polymorphism of the MIF gene was determined using polymerase chain reaction restriction fragment length polymorphism methods. Serum MIF concentration was measured using sandwich enzyme-linked immunosorbent assay. The allele frequency of the C allele was higher in SRNS compared with that of SSNS patients (P=0.025). There was a trend toward an association between genotypes and serum MIF disturbances. In conclusion, this study noted elevated circulating serum MIF levels and higher frequency of the C allele of the MIF gene in SRNS patients. The presence of the C allele implies an increased risk for steroid resistance.

Effects of lifestyle intervention on weight and metabolic parameters in patients with impaired glucose tolerance related to beta-3 adrenergic receptor gene polymorphism Trp64Arg(C/T): Results from the Japan Diabetes Prevention Program.

The beta‐3 adrenergic receptor (ADRB3), primarily expressed in adipose tissue, is involved in the regulation of energy metabolism. The present study hypothesized that ADRB3 (Trp64Arg, rs4994) polymorphisms modulate the effects of lifestyle intervention on weight and metabolic parameters in patients with impaired glucose tolerance. Data were analyzed from 112 patients with impaired glucose tolerance in the Japan Diabetes Prevention Program, a lifestyle intervention trial, randomized to either an intensive lifestyle intervention group or usual care group. Changes in weight and metabolic parameters were measured after the 6‐month intervention. The ADRB3 polymorphisms were determined using the polymerase chain reaction restriction fragment length polymorphism method. Non‐carriers showed a greater weight reduction compared with the carriers in both the lifestyle intervention group and usual care group, and a greater increase of high‐density lipoprotein cholesterol levels than the carriers only in the lifestyle intervention group. ADRB3 polymorphisms could influence the effects of lifestyle interventions on weight and lipid parameters in impaired glucose tolerance patients.

Impact of IL-8-251A/T gene polymorphism on severity of disease caused by enterovirus 71 infection.

The study was performed in EV71-infected patients, with 97 mild cases and 80 severe cases. IL-8251A/T genotypes were determined by the polymerase chain reaction restriction fragment length polymorphism technique. Severe cases had a significantly higher frequency of the IL8-251 AT and TT genotypes than mild cases (52.5% vs. 49.5% and 42.5% vs. 30.9%, respectively; p=0.024). The frequency of IL-8-251T alleles among the severe cases was also significantly higher than that of mild cases (68.7% vs. 55.7%, OR=1.8, 95% CI=1.1-2.7, p=0.012). There were significant differences in gender, age, fever days, WBC, CRP and BG concentration, and IL-8 levels among genotypes of IL-8251A/T in EV71-infected patients, but there were no significant differences in ALT, AST, CK-MB and EV71 loads. These findings suggested that the IL-8-251T allele is associated with susceptibility to severe disease in Chinese patients infected with EV71.

FAS and FAS-Ligand Promoter Polymorphisms in Hepatitis B Virus Infection.

Background:The FAS and FAS-Ligand (FASL) system is an important apoptosis pathway in the liver. The FAS-mediated pathway functions by binding the FASL on the activated cytotoxic T lymphocytes and Natural Killer (NK) cells to the FAS receptor on infected hepatocytes. FAS and FASL polymorphisms, which are related to apoptosis, might influence the outcome of Hepatitis B Virus (HBV) infection.Objectives:Thus, the present study aimed to determine if FAS and FASL promoter polymorphisms are associated with the clinical outcome of HBV infection.Patients and Methods:DNA samples were obtained from the infected individuals including chronic carrier (n = 50), chronic hepatitis (n = 50), cirrhosis (n = 25), naturally recovered (n = 26) and compared with those of their matched healthy controls (n = 100). Genotyping for polymorphisms of FAS-670 A/G and -1377 G/A, and FASL -844 C/T was performed using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assays.Results:Multiple analyses for genetic association of FAS and FASL polymorphisms were not statistically different between HBV patients (n = 125) and healthy controls (n = 100). However, genotype and allele frequencies of FASL-844 C/T were significantly different between recovered individuals and patients with cirrhosis (P = 0.02 and P=0.01, respectively). Whereas, FAS-670A/G and -1377G/A polymorphisms were similarly distributed in these two groups (P = 0.8 and P = 0.47, respectively).Conclusions:The current study results showed that bearing -844T allele in FASL promoter region has a protective effect on cirrhosis and is involved in recovery from infection. In conclusion, it is proposed that HBV infection outcome might be influenced by FASL-844C/T polymorphism through alteration in apoptosis of hepatocytes.

Association Study between an SNP in CD147 and Its Expression With Acute Coronary Syndrome in a Jiangsu Chinese Population.

CD147 is an important molecule in the inflammation and proteolysis process. This molecule crucially contributes to the initial and progression of atherosclerotic lesions. A single nucleotide polymorphism in CD147 gene, the rs8259 T/A in the 3′-untranslated region, is responsible for its expression in various cells. This study assessed whether the genetic variation rs8259 is associated with acute coronary syndrome (ACS) and CD147. A total of 943 ACS subjects and 439 stable angina subjects, and 851 controls were genotyped for rs8259 polymorphism by polymerase chain reaction restriction fragment length polymorphism and DNA-sequencing method. Plasma soluble CD147 (sCD147) level was measured by enzyme-linked immunosorbent assay. CD147 mRNA and protein expression in peripheral blood mononuclear cells were tested by real-time quantitative polymerase chain reaction and western blot, respectively. We found that TT genotype and T-allele frequency of CD147 rs8259 in ACS patients were much lower than the other patient groups. Significant difference was not observed between stable angina and controls. CD147 T allele was negatively related to ACS. ACS patients exhibited the highest CD147 expression in peripheral blood mononuclear cells and plasma sCD147 level. The plasma sCD147 levels in the culprit vessel were higher than those in the radial artery. In ACS patients, AA gene carriers had the highest CD147 levels, whereas TT gene carriers had the lowest CD147 levels. Linear regression analysis showed that genotypes and disease conditions contributed 49% to the change of the plasma CD147 level. These results suggested that the single nucleotide polymorphism of CD147 gene rs8259 T/A was associated with ACS susceptibility. Allele T gene may decrease the relative risk of suffering from ACS through downregulation of CD147 expression.

Genotyping of Toxoplasma gondii Directly from Human and Animal Biological Samples: From Partial Genotypes to a New Genotype.

Genotyping of Toxoplasma gondii is traditionally performed using DNA obtained from tachyzoites after isolation by bioassay in mice. In this study, genotyping of T. gondii was performed by multiplex nested polymerase chain reaction restriction fragment length polymorphism (Mn-PCR-RFLP) in DNA obtained from the lungs of experimentally infected mice, the hearts of naturally infected free-range chickens, and human blood samples of newborns with congenital toxoplasmosis. The efficiency of Mn-PCR varied according to the marker. We obtained complete genotypes of all of the mice lung samples. In chickens, total or partial genotyping was performed on all of the 15 samples. Two complete genotypes were obtained, including one identified for the first time, and another previously described in different hosts including dogs, cats, and humans. In blood from infants, partial genotypes were obtained in 8 of the 12 samples. Mouse bioassay is the most efficient method to obtain DNA from T. gondii , but direct tissue genotyping enhances the likelihood of obtaining molecular information on T. gondii and is an effective tool as a complement to isolation in mice. In this study, we genotyped Toxoplasma gondii directly from human (blood samples of newborns with congenital toxoplasmosis) and free-range chickens (hearts) by Mn-PCR-RFLP. We present partial and complete genotypes and provide technical and scientific information about T. gondii genotyping methods.

Association between polymorphisms in transforming growth factor-β1 and sporadic Alzheimer's disease in a Chinese population

Alzheimer's disease (AD) is the most common neurodegenerative disorder of the brain. It causes the slow progressive loss of cognitive functions that ultimately leads to dementia and death in the elderly. The etiology and mechanism of late-onset AD (LOAD) are poorly understood, and genetic factors might play an important role in the development of AD. The aim of this study was to investigate the association between common polymorphisms in TGF-β1 with LOAD in a Chinese Han population. Two single nucleotide polymorphisms in TGF-β1 (rs1800469 and rs1982073) were genotyped in 202 patients with sporadic LOAD and 225 control subjects using polymerase chain reaction restriction fragment length polymorphism. Our results showed that rs1800469 in TGF-β1 were significantly associated with LOAD. The frequencies of the AC genotypes of rs1800469 were significantly higher in the LOAD patients than in the control subjects (42.5% vs 28.6%; P = 0.001). The minor allele (C) frequency was significantly higher in patients with LOAD than in control subjects (30.7% vs. 21.0%; P = 0.001). The genotypes and allele of rs1982073 in TGF-β1 were also significantly associated with LOAD. The frequency of the TG genotype of rs1982073 was significantly higher in the LOAD patients than in the control subjects (38.1% vs. 27.1%; P = 0.013). The minor allele (G) frequency was significantly higher in patients with LOAD than in control subjects (22.2% vs. 16.7%; P = 0.032). These results suggest that common variants in TGF-β1 might contribute to the development of LOAD in the Chinese population.

Polymorphic variants in vitamin D signaling pathway genes and the risk of endometriosis-associated infertility.

It has recently been reported that vitamin D blood plasma levels are associated with reduced risk of endometriosis. The present study aimed to investigate whether the vitamin D binding protein (GC), vitamin D receptor (VDR), and retinoid X receptor (RXR) gene variants may be genetic risk factors for endometriosis‑associated infertility. The subjects consisted of 154 women with endometriosis‑associated infertility and 347 controls. Using polymerase chain reaction restriction fragment length polymorphism and high resolution melt techniques, the GC rs1155563, rs2298849 and rs7041; RXRA rs10881578, rs10776909 and rs749759; VDR BsmI rs1544410; and FokI rs2228570 single nucleotide polymorphisms (SNPs) were investigated in the patients with endometriosis and the healthy controls. The results indicated that no significant differences were observed between the genotype and allele frequencies of all experimental SNPs in the vitamin D signaling pathway genes in women with endometriosis-associated infertility and controls. However, a significant association was present between the A‑T haplotype, consisting of VDR rs1544410 and rs222857 minor alleles, and endometriosis-associated infertility [OR=1.659 (1.122‑2.453), P=0.011]. The results of the present study suggested that VDR gene variants act as genetic risk factors for endometriosis‑associated infertility.

MTHFR-Ala222Val and male infertility: a study in Iranian men, an updated meta-analysis and an in silico-analysis

Methylenetetrahydrofolate reductase (MTHFR) functions as a main regulatory enzyme in folate metabolism. The association of MTHFR gene Ala222Val polymorphism with male infertility in an Iranian population was investigated by undertaking a meta-analysis and in-silico approach. A genetic association study included 497 men; 242 had unexplained infertility and 255 were healthy controls. Polymerase chain reaction restriction fragment length polymorphism was used for genotyping MTHFR-Ala222Val. OpenMeta[Analyst] software was used to conduct the analysis; 22 studies were identified by searching PubMed and the currently reported genetic association study. A novel in-silico approach was used to analyse the effects of Ala222Val substitution on the structure of mRNA and protein. Genetic association study revealed a significant association of MTHFR-222Val/Val genotype with oligozoospermia (OR 2.32; 95% CI, 1.12 to 4.78; P = 0.0451) and azoospermia (OR 2.59; 95% CI 1.09 to 6.17; P = 0.0314). Meta-analysis for allelic, dominant and codominant models showed a significant association between Ala222Val polymorphism and the risk of male infertility (P < 0.001). In silico-analysis showed MTHFR-Ala222Val affects enzyme structure and could also change the mRNA properties (P = 0.1641; P < 0.2 is significant). The meta-analysis suggested significant association of MTHFR-Ala222Val with risk of male infertility, especially in Asian populations.

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.

Association between genetic polymorphisms in folate-related enzyme genes and infertile men with non-obstructive azoospermia

Polymorphisms in the genes encoding enzymes in the folate metabolism pathway have been associated with male infertility and chromosome abnormalities. The aim of this study was to analyze the distribution of the methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR), and methionine synthase reductase (MTRR) polymorphisms in fertile men and infertile men with non-obstructive azoospermia (NOA). A case-control study comprising 85 infertile men with NOA and 246 fertile men as controls was carried out. MTHFR c.677C > T (rs1801133), MTHFR c.1298A > C (rs1801131), MTR c.2756A > G (rs1805087), and MTRR c.66A > G (rs1801394) polymorphisms were determined using the polymerase chain reaction restriction fragment length polymorphism technique. There were significant differences in AC + CC genotype (OR = 1.9, 95% CI = 1.1–3.2) and C allele frequencies (OR = 1.8, 95% CI = 1.2–2.8) of MTHFR c.1298A > C polymorphism between NOA patients and controls after applying the Bonferroni correction. Moreover, the 1298AC genotype, 1298AC + CC genotype, and 1298C allele frequencies were statistically significant in NOA with chromosomal abnormalities and/or a Y chromosome deletion compared to the controls (AC genotype: OR = 3.0; AC + CC genotype: OR = 3.0; C allele: OR = 2.3). Considering the other polymorphisms, no differences were found between cases and controls. Our findings suggest the MTHFR c.1298A > C polymorphism is associated with an increased risk of male infertility, i.e., NOA.