The nitric oxide synthase 3 gene polymorphisms and their association with deep vein thrombosis in Asian Indian patients

Nitric Oxide Synthase 3 Gene Polymorphisms and Their Association with Acute Myocardial Infarction and Chronic Stable Angina: A Case-Control Study from Northern India

Background

Coronary artery disease (CAD) that encompasses acute myocardial infarction (AMI), chronic stable angina (CSA), and unstable angina (UA) has numerous known risk factors. Genetic predispositions contribute as major risk in the development of CAD and the genes regulating atherosclerosis are important for disease prevention. Nitric oxide synthase 3 (NOS3) gene responsible for nitric oxide (NO) production is of special importance.

Aim

To evaluate the role of three NOS3 polymorphisms (-786C/T, 894G/T, and 4a4b) in patients with CAD, particularly in AMI and CSA and their comparison with healthy controls.

Materials and Methods

One hundred patients in each AMI and CSA group and 100 controls were included and were typed for three NOS3 polymorphisms (-786C/T, 894G/T, and 4a4b) by polymerase chain reaction-restriction fragment length polymorphism. Plasma NO metabolites (NOx) were also evaluated.

Results

A significant association of 894G/T polymorphism with AMI in dominant model (P = 0.052) and with CSA in dominant and codominant models was detected (P = 0.008 and P = 0.006, respectively). Plasma NO levels were found to be significantly higher (P < 0.0001) in healthy controls (43.80 ± 6.28) compared to AMI and CSA patients (37.05 ± 6.75 and 38.67 ± 5.61). No significant association of -786C/T and 4a4b polymorphism with AMI and CSA risk under recessive, dominant, and codominant models was detected.

Conclusion

Our study revealed a significant association of 894G/T polymorphism with AMI and independent association of NOx levels with CAD, indicating high risk of CAD in the North Indian population. Our findings will be helpful in identifying the genetic risk factors associated with CAD and better management of the diagnostic as well as therapeutic measures.

Endothelial nitric oxide synthase polymorphism and venous thromboembolism: A meta-analysis of 9 studies involving 3993 subjects

BACKGROUND

Endothelial nitric oxide synthase (eNOS) polymorphism may influence the risk of venous thromboembolism (VTE). However, data from published studies with low statistical power are inconclusive. The present meta-analysis aimed to assess the relationship between eNOS polymorphism and the risk of VTE.

METHOD

Case-control studies evaluating the association between the eNOS polymorphism and VTE were searched in PubMed, Embase, Web of Science, Google Scholar, Wanfang, Chinese National Knowledge Infrastructure (CNKI), the Chongqing VIP Chinese Science and Technology Periodical Database (VIP), and Chinese Biomedical Literature Database (CBM).

RESULTS

A total of 1588 cases and 2405 controls from 9 studies were included in the analysis. The results showed that eNOS G894T polymorphism was related to VTE susceptibility and the difference was statistically significant [T vs G: OR = 1.41, 95% CI (1.13, 1.75), P = 0.002; TT + GG vs TG: OR = 0.71, 95% CI (0.60, 0.84), P = 0.000; TT + TG vs GG: OR = 1.45, 95% CI (1.23, 1.70), P = 0.000]. Additionally, eNOS Intron 4 VNTR polymorphism was related to VTE susceptibility and the difference was statistically significant [4b4b vs 4a4a + 4a4b: OR = 2.77, 95% CI (1.01, 7.61), P = 0.048].

CONCLUSION

ENOS G894T and eNOS Intron 4 VNTR polymorphisms were associated with VTE susceptibility, especially in Asian populations. However, multicenter studies with larger samples should be conducted to further clarify this association and verify our findings.

The Effect of Common Variants in SLC44A2 on the Contribution to the Risk of Deep Cein Thrombosis after Orthopedic Surgery

Aim: Deep vein thrombosis (DVT) is a common complication of orthopedic surgery. Multiple lines of evidence indicate that genetic factors play an important role in the development of DVT following orthopedic surgery (DVTFOS). Recent evidence suggested that the solute carrier family 44 member 2 (SLC44A) gene may contribute to the risk of DVT. In this study, we aimed to investigate the associations of SLC44A2 and DVTFOS in Chinese Han individuals.

Methods: In the study, 2,655 subjects, including 689 DVTFOS patients and 1,966 controls, were recruited. Eighteen SNPs were genotyped in the study. Genetic association analyses were performed at both the single marker and haplotype levels. Bioinformatics analyses were conducted to predict the functional consequences of significant SNPs.

Results: SNP rs2288904 of SLC44A2 was identified as being significantly associated with DVTFOS (P = 0.0003, OR [95%CI]= 1.28[1.12–1.46]). Allelic analyses showed that the G allele of this SNP significantly elevated the risks of DVTFOS, which was replicated in the genotypic association analyses. Moreover, a two-SNP haplotype, including rs2288904, was found to be strongly correlated with the risk of DVTFOS (P = 4.15 × 10⁻¹¹). Widespread effects in the expression quantitative trait loci were identified for rs2288904 in multiple tissues.

Conclusion: In summary, our results provide further supportive evidence of the association of SLC44A2 with the risk of DVTFOS, which also provide clues for understanding the important roles of the SLC44A2 gene in the pathogenesis of DVTFOS and in the development of preventive strategies.

Challenges imposed by minor reference alleles on the identification and reporting of clinical variants from exome data

Background

The conventional variant calling of pathogenic alleles in exome and genome sequencing requires the presence of the non-pathogenic alleles as genome references. This hinders the correct identification of variants with minor and/or pathogenic reference alleles warranting additional approaches for variant calling.

Results

More than 26,000 Exome Aggregation Consortium (ExAC) variants have a minor reference allele including variants with known ClinVar disease alleles. For instance, in a number of variants related to clotting disorders, the phenotype-associated allele is a human genome reference allele (rs6025, rs6003, rs1799983, and rs2227564 using the assembly hg19). We highlighted how the current variant calling standards miss homozygous reference disease variants in these sites and provided a bioinformatic panel that can be used to screen these variants using commonly available variant callers. We present exome sequencing results from an individual with venous thrombosis to emphasize how pathogenic alleles in clinically relevant variants escape variant calling while non-pathogenic alleles are detected.

Conclusions

This article highlights the importance of specialized variant calling strategies in clinical variants with minor reference alleles especially in the context of personal genomes and exomes. We provide here a simple strategy to screen potential disease-causing variants when present in homozygous reference state.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4433-3) contains supplementary material, which is available to authorized users.

Risk indicators for venous thrombosis in first-degree relatives of patients with recurrent venous thromboembolism in Chinese

Having encountered several subjects with venous thromboembolism (VTE) in 1 family in which 1 proband has recurrent VTE (rVTE), we aimed to assess the risk of VTE in first-degree relatives, especially the children of individuals with rVTE, and to investigate the association of endothelial nitric oxide synthase (eNOS) G894T polymorphism between Chinese persons with rVTE and their offspring.We collected information about family histories and blood samples from 126 individuals with rVTE who had presented to our institute from 2003 to 2014, and 126 population-based controls and the first-degree relatives of subjects in these 2 groups. We tested blood samples for heritable thrombophilia and calculated odds ratios (ORs) and kappa coefficients.First-degree relatives of individuals with rVTE patients had a statistically significant risk of developing VTE (OR 2.62, 95% confidence interval [CI] 1.61-4.26, P < 0.001). For siblings, the OR was 2.72 (95% CI 1.56-4.73, P < .001). Moreover, for each year that the patient was older, the OR was 0.98 (95% CI 0.97-0.99, P = 0.03). One (11.2%) of the 9 individuals who had the same eNOS G894T polymorphism as their probands had a history of VTE, whereas none of the 17 relatives without the same polymorphism had developed VTE. The associations between patients and their children were statistically significant for VTE (kappa = 0.23, P < 0.001) and for eNOS G894T (kappa = 0.03, P = 0.04).In this case-controlled study, we demonstrated a higher risk of VTE among first-degree relatives of individuals with rVTE, especially in siblings of younger subjects with rVTE. We also found that eNOS G894T polymorphism may be a predictor of VTE in offspring of individuals with rVTE.

Endothelin-1 Gene Polymorphism and Its Level Predict the Risk of Venous Thromboembolism in Male Indian Population

Objectives:

Genes related to endothelial function are responsible for the regulation of vascular functions.

Aim:

The aim of this study is to investigate whether endothelial gene-associated polymorphism and their plasma levels can be used to predict the risk for venous thromboembolism (VTE).

Methods:

We studied 133 patients with VTE and 164 healthy controls. Endothelin (EDN) G8002A, EDN T1370G, EDN 3A/4A, eNOSG894T, angiotensin-converting enzyme I/D, vascular endothelial growth factor C936T, and endothelial cell protein C receptor A6936G polymorphism was genotyped by restriction fragment length polymorphism. Plasma levels of endothelin 1 (EDN1), endothelial nitric oxide synthase, and angiotensin-converting enzyme were measured by enzyme-linked immunoassay kit.

Results:

The genotype and allele frequency between control and patients with VTE were significantly altered only for EDN T1370G polymorphism. The plasma EDN1 concentration was relatively higher in patients with VTE ( P = .0017) compared to healthy controls and showed an association with the EDN1 gene polymorphism in male Indian population. Logistic regression model analysis for EDN T1370G indicated a significant association between EDN G allele and occurrence of VTE.

Conclusion:

The EDN1 gene polymorphism may play a significant role in predicting individual’s susceptibility toward VTE and its clinical progression.

Endothelial nitric oxide gene polymorphisms and their association with coronary artery disease in Tunisian population

OBJECTIVE

By releasing mediators, like nitric oxide (NO), vascular endothelium is considered so significant in the process of atherosclerotic . In fact, the major functions of NO consist in inhibiting the activation of platelet, relaxing the muscles (vascular and smooth ones), and modulating the growth and the migration of cells (vascular and smooth ones). Therefore, this process makes the endothelial nitric oxide synthase (NOS3) considerably important because it possesses atheroprotective activity. Polymophisms, rs1808593 (10G/T) as well as rs891512 (G24943A) within NOS3 gene, play major role in the coronary artery disease (CAD) development. The aim of the study is to evaluate the relationship between the 10G/T and G24943A polymorphisms and the CAD among Tunisian individuals.

METHODS

We included, in this survey, a set of 274 patients suffering from CAD together with 162 normotensive subjects. The PCR-RFLP was applied to analyze the polymorphism of intron 23 (10G/T) gene, while the ASA-PCR was used to analyze the intronic G24943A gene polymorphism. Overall and subgroup analyses were performed. Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the association between NOS3 10G/T and G24943A polymorphisms as well as CAD risk. Statistical analysis was performed with SPSS V.10.

RESULTS

The genotype frequencies for G24943A polymorphism differed significantly between the CAD patients and the controls. The former had a frequency of 11.4% for the AA genotype, 34.7% for the GA genotype and 53.9% for the GG genotype. The latter had a frequency of only 2.5% for the AA genotype, 29.7% for the GA genotype and 67.7% for the GG genotype (χ2=7.62; OR=1.79; p=0.006). The CAD patient group showed a significantly-higher frequency of the A allele compared to the controls (0.28 vs. 0.16; χ2=15.20; p<0.001). The odds ratio of CAD for A vs. G allele frequency was statistically significant 1.99 (1.4-2.82) at 95% CI. The genotype distribution for the 3 investigated variants of 10G/T were not significantly different between CAD and control subjects (χ2=1.46; OR=1.72; p=0.22). Whereas, 10G/T has revealed barely allelic (χ2=4.45; OR=2.3; p=0.034) correlation with coronary artery disease Conclusion: The present study was designed so that there would be an association between the CAD and NOS3 polymorphism (G24943A). However, these results have proven that the polymorphism of 10G/T is not associated with CAD in the Tunisian population.

Progress in research into the genes associated with venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE), including both deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common, lethal disorder that affects hospitalized and non-hospitalized patients. This study aimed to review the progress in the research into VTE.

DATA SOURCES

We reviewed the studies about VTE and verified different genetic polymoriphisms of VTE.

RESULTS

The pathogenesis of VTE involves hereditary and acquired factors. Many studies indicated that the disorder of coagulation and fibirnolytic system is of utmost importance to this disease. Genetic polymoriphism-related VTE demonstrated significant differences among geographies and ethnicities.

CONCLUSION

VTE has many risk factors, but genetic factors play an important role.

Decanucleotide insertion polymorphism of F7 significantly influences the risk of thrombosis in patients with essential thrombocythemia

OBJECTIVE

There is strong evidence that certain thrombophilic single nucleotide polymorphisms (SNPs) account for an increased risk of thrombosis. The additive impact of inherited thrombotic risk factors to a certain disease- immanent thrombotic risk is vastly unknown. Therefore, we aimed to investigate the influence of three novel, preselected SNPs on the risk of thrombosis in patients diagnosed with myeloproliferative neoplasm (MPN).

METHOD

In 167 patients with a diagnosis of essential thrombocythemia (ET) or prefibrotic primary myelofibrosis (PMF) thrombophilic SNPs in the genes of factor VII (F7), nitric oxide synthase 3 (NOS3) and FcɣRIIa (FCGR2A) were determined. Subsequently, the polymorphic variants were correlated with the incidence of major thrombosis after diagnosis.

RESULTS

Decanucleotide insertion polymorphism of F7 emerged as an independent, significant risk factor for total thrombosis and arterial thrombosis in particular in the whole group of patients (P = 0.0007) as well as in the separate analysis of patients with ET (P = 0.0002).

CONCLUSION

Our results illustrate that the risk of thrombosis in MPN is significantly multiplied by inherited thrombophilic SNPs. This result points to the importance of a combined consideration of the inherited and the acquired hypercoagulable state in patients with MPN. Larger studies are needed to confirm and extend these important findings.

Apolipoprotein E polymorphism is associated with lower extremity deep venous thrombosis: color-flow Doppler ultrasound evaluation

Introduction

Apolipoprotein E (apoE) is a member of apolipoprotein family, and its gene polymorphisms seem to have some impact among patients with cardiovascular disease. However, its role in the lower extremity deep venous thrombosis (LEDVT) has not been well studied. The objective of this study was to investigate the potential association between APOE gene polymorphisms and LEDVT.

Materials and methods

A hospital-based case–control study was conducted in 300 patients with LEDVT by color-flow Doppler ultrasound and 300 age- and gender-matched healthy controls. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay was applied to assess the APOE gene polymorphisms.

Results

Patients with LEDVT had a significantly higher frequency of APOE E3/E4 genotype [odds ratio (OR) =1.48, 95% confidence interval (CI) = 1.05, 2.10; P = 0.03] than healthy controls. When stratifying by family history of LEDVT, it was found that patients with positive family history of LEDVT had a significantly higher frequency of APOE E3/E4 genotype (OR =1.68, 95% CI = 1.04, 0.95; P = 2.70). When stratifying by smoking status, presence of varicose veins, type 2 diabetes mellitus and any hormone administration before, no significant differences were found in any groups.

Conclusion

Our study suggested that APOE E3/E4 genotype was associated with a higher LEDVT risk. Additional studies are needed to confirm this finding.

Association of the 894G>T polymorphism in the endothelial nitric oxide synthase gene with risk of venous thromboembolism in Chinese population

INTRODUCTION

Endothelium derived nitric oxide (NO) is a key mediator of vascular homeostasis. Endothelial nitric oxide synthase (eNOS) gene, by affecting the expression and functional activity of the eNOS enzyme, thereby reducing NO availability, may be implicated in venous thromboembolism (VTE). We investigated the eNOS G894T polymorphism in VTE patients in the Chinese population.

MATERIALS AND METHODS

A case-control study was conducted in a general hospital. Blood samples, collected from 462 consecutive patients with VTE and 462 healthy controls, were used for DNA extraction. Single nucleotide polymorphisms (SNP) of eNOS (894G/T) were determined by allele specific-polymerase chain reaction (ARMS-PCR) analysis.

RESULTS

The eNOS 894G/T polymorphism alleles distribution was in agreement with the principle of Hardy-Weinberg equilibrium. The prevalence of homozygote, heterozygote and pathological homozygote for the eNOS G894T polymorphism in VTE patients was 79.7%, 18.1% and 2.2%, respectively (controls: 86.6%，12.3% and 1.1%). T allele distribution in the VTE (11.3%) and especially the male VTE patients (12.5%) was more common than in healthy controls (7.3%). The frequency of GT+TT genotype was significantly higher among the age≤55years patients in VTE group than in controls (20.1% vs. 12.2%, P=0.033).

CONCLUSION

Our result demonstrates that the 894G/T polymorphism variant of eNOS is a risk factor for VTE in Chinese population.