Common C677T polymorphism in the methylenetetrahydrofolate reductase gene increases the risk for deep vein thrombosis in patients with predisposition of thrombophilia

Ductus Arteriosus Aneurysm and Pulmonary Artery Thromboses in a Protein S-Deficient Newborn

Ductus arteriosus aneurysm (DAA) asymptomatically occurs in newborn infants and resolves spontaneously. High-risk DAA with compression, rupture, and thrombosis requires early surgical intervention. Newborn infants have the highest risk of thrombosis among pediatric patients, but the genetic predisposition is difficult to determine in infancy. We herein report a neonatal case of massive thromboses in DAA and pulmonary artery. Desaturation occurred in an active full-term infant 2 days after birth. Echocardiography and contrast-enhanced computed tomography indicated thrombotic occlusion of the DAA and pulmonary artery thrombus. Urgent thrombectomy and ductus resection were successfully performed. After 6 months of anticoagulant therapy, the dissociated low plasma activity levels of protein S from protein C suggested protein S deficiency. A genetic study of PROS1 identified a heterozygous variant of protein S K196E, a low-risk variant of thrombophilia in Japanese populations. There have been seven reported cases with neonatal-onset symptomatic thromboses of DAA involving the pulmonary artery. All survived without recurrence after surgical intervention in five and anticoagulant therapy alone in two. Two newborns had a heterozygous methylenetetrahydrofolate reductase ( MTHFR ) variant, but information on thrombophilia was not available for any other cases. A genetic predisposition may raise the risk of DAA thrombosis, leading to rapid progression.

Integrative analyses of genes about venous thromboembolism: An umbrella review of systematic reviews and meta-analyses

BACKGROUND

In recent years, many studies have found possible links between gene polymorphisms and venous thromboembolism (VTE). By identifying genetic risk factors before facing environmental risk factors such as surgical interventions and COVID-19 vaccination, we could rapidly respond to the risk of VTE. The aim of this study was to perform an umbrella review of genetic variants related to VTE. Integrative gene analysis of VTE was performed to identify critical genetic variations.

METHODS

This study conducted an umbrella review of systematic reviews and meta-analyses. All included studies were selected from the PubMed/MEDLINE database. To select eligible studies, the following variables were extracted: first author name; effect size of each study genetic variant; year of publication; the number of studies included in each article; ethnicity, sample size, P values, and heterogeneity estimates. To assess cumulative evidence in genetic epidemiology about effects of gene polymorphisms on VTE, Human Genome Epidemiology Network's Venice criteria were used. Methodological quality assessment was conducted with JBI Critical Appraisal Checklist for Systematic Reviews and Research Syntheses.

RESULTS

Genes provided in the present study with genetic variants associated with VTE were FVL (G1691A), Prothrombin (G20210A), MTHFR (C677T, A1298C), PAI-1 (4G/5G), factor VII activating protease (1601G > A), and endothelial protein C receptor (g.6936A_G, c.4600A_G). Among them, variants in FVL, Prothrombin, MTHFR, and PAI-1 showed high significance. Particularly, variants in Prothrombin (G20210A), MTHFR (C677T), and PAI-1 (4G/5G) had more than 2 types of model significance.

CONCLUSION

The present study performed a systematic review of genetic variants associated with VTE. Our results could lead to a more comprehensive understanding of VTE etiology. These results could give a strategy of prediagnosis about evaluating individual risks of VTE who might be exposed to environmental risk factors.

Venous thromboembolism associated with hyperhomocysteinemia, homozygosity for the methylenetetrahydrofolate reductase 677C>T gene variant, and secondary polycythemia

: The development of pulmonary embolism/deep vein thrombosis (DVT) in the extremities is influenced by various risk factors. Hyperhomocysteinemia is one such risk factor, which may be associated with vitamin B12/folate deficiency, or the methylenetetrahydrofolate reductase gene variant, 677C>T. Here, we report a 47-year-old male who developed pulmonary embolism/DVT, associated with hyperhomocysteinemia (plasma homocysteine: 71.9 nmol/ml; reference range: 6.3-18.9 nmol/ml) and was homozygous (T/T) for the methylenetetrahydrofolate reductase variant. Serum levels of vitamin B12 and folate were within the normal range, while secondary polycythemia (hemoglobin: 18.2 g/dl and hematocrit: 50.8%) may have acted as an additional trigger for the thromboembolism. The pulmonary embolism/DVT was successfully managed and the patient has been doing well for longer than 3 years.

High prevalence of factor V Leiden and prothrombin G20101A mutations in Kashmiri patients with venous thromboembolism

AIM

The genetic variants of the factor V (G1691A), prothrombin (G20210A) and MTHFR (C677T) genes have been widely implicated as inherited risk factors for developing venous thrombosis. This study was undertaken to reveal the frequency of these mutations in Kashmiri patients with venous thromboembolism.

METHODOLOGY

A case-control study was designed with 250 VTE patients and 250 healthy controls. The mutations were analysed using ARMS-PCR and PCR-RFLP approach.

RESULT

The factor V Leiden G1691A mutation was found in 17/250 (6.8%) VTE patients and prothrombin G20210A mutation was found in 7/250 (2.8%) VTE patients while no mutation was found in any of the healthy controls. Both the mutations were found to be significantly associated with the increased risk of VTE (p = 0.0001 and 0.0150 respectively) while no association of VTE risk with MTHFR C677T polymorphism was found (p = 0.53).

CONCLUSION

The increased frequency of factor V Leiden G1691A and prothrombin G20210A mutation in VTE patients indicates a significant role of these mutations in the development of VTE in our population. We therefore suggest the routine screening of these two mutations as thrombophilic markers in Kashmiri patients with venous thromboembolism.

Role of polymorphisms in BCL-2 and BAX genes in modulating the risk of developing non-Hodgkin lymphoma

The aim of this study was to investigate whether polymorphisms of - 938C/A and Thr43Ala in the BCL-2 gene and G - 248A in the BAX gene are associated with the risk of developing non-Hodgkin lymphoma (NHL). We genotyped polymorphisms of - 938C/A and Thr43Ala in the BCL-2 gene and G-248A in the BAX gene among 424 patients with NHL and 446 controls. We found that the - 938AA genotype of the BCL2 gene was significantly associated with the risk of developing NHL (p < 0.001) and this genotype was associated with advanced stage (p = 0.01). Meanwhile, individuals having - 248AG + AA genotypes were significantly associated with an increased risk of NHL (p = 0.01), and these genotypes were associated with larger tumor size (p = 0.02). The present study demonstrated that the - 938AA genotype of the BCL-2 gene and - 248AG + AA genotype of the BAX gene may be susceptible genotypes for NHL. There appeared to be an impact of the BCL2 - 938AA genotype on advanced stage and - 248AG + AA genotypes on tumor size in NHL.

The 677C>T Mutation of the MTHFR Gene Increases the Risk of Venous Thromboembolism in Koreans and a Meta-Analysis From Asian Population

The frequency of methylenetetrahydrofolate reductase (MTHFR) mutations varies between racial and ethnic groups, and there are also conflicting data regarding MTHFR gene mutations in Asian patients with venous thromboembolism (VTE). The aim of this study was to examine the association between common MTHFR gene mutations (677C>T and 1298A>C) and risk of VTE in Koreans. This study was a retrospective case–control study. We enrolled 203 patients with VTE and 403 controls. For the 677C>T polymorphism, there was no difference in the frequency of the CT genotype and TT genotype between the patients with VTE and the controls. However, in the recessive analysis (CC + CT vs TT), the frequency of the TT genotype was significantly higher in VTE than in controls (odds ratio = 1.700; 95% confidence interval = 1.108-2.607, P = .015). In conclusion, the TT genotype of MTHFR 677C>T increases the risk of VTE in Koreans. This finding was supported by meta-analysis of previous Asian studies.

Creatine kinase MM TaqI and methylenetetrahydrofolate reductase C677T and A1298C gene polymorphisms influence exercise-induced C-reactive protein levels

Physical training induces beneficial adaptations, but exhausting exercise increases reactive oxygen species, which can cause muscular injuries with consequent inflammatory processes, implying jeopardized performance and possibly overtraining. Acute strenuous exercise almost certainly exceeds the benefits of physical activity; it can compromise performance and may contribute to increased future risk of cardiovascular disease (CVD) in athletes. Polymorphisms in the muscle-type creatine kinase (CK-MM) gene may influence performance and adaptation to training, while many potentially significant genetic variants are reported as risk factors for CVD. Therefore, we investigated the influence of polymorphisms in CK-MM TaqI and NcoI, methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and C-reactive protein (CRP G1059C) genes on exercise-induced damage and inflammation markers. Blood samples were taken immediately after a race (of at least 4 km) that took place outdoors on flat tracks, and were submitted to genotyping and biochemical evaluation of aspartate aminotransferase (AST), CK, CRP and high-sensitivity CRP (hs-CRP). CK-MM TaqI polymorphism significantly influenced results of AST, CK and hs-CRP, and an association between MTHFR C677T and A1298C with CRP level was found, although these levels did not exceed reference values. Results indicate that these polymorphisms can indirectly influence performance, contribute to higher susceptibility to exercise-induced inflammation or protection against it, and perhaps affect future risks of CVD in athletes.

Inherited risk factors for deep venous thrombosis following total hip arthroplasty in Japanese patients: matched control study

BACKGROUND

Inherited predisposing risk factors for deep venous thrombosis (DVT) have been clearly identified in Caucasians, but there are fewer reports evaluating these factors in the Japanese. This study was undertaken to assess the predisposing risk factors for DVT following elective total hip arthroplasty (THA) in Japanese patients.

METHODS

We studied 60 patients who underwent THA. The study group consisted of 30 patients who developed DVT diagnosed by duplex sonography examination; the 30 patients who did not develop DVT served as a control group. They were matched in age, sex distribution, diagnosis (osteoarthritis secondary to dysplastic hip), and operation side(s) (bilateral or unilateral). Protein C, protein S, antithrombin III, and plasminogen activities and the plasma homocysteine level were measured. Three polymorphisms were screened for the factor V Leiden polymorphism, the factor II G20210A polymorphism, and the methylene tetrahydrofolate reductase C677T polymorphism.

RESULTS

Plasma protein C activity was 82.39% +/- 14.24% in the DVT patients and 88.76% +/- 23.27% in the controls. Plasma protein C activity was significantly reduced in the study group, whereas other serologic and genetic analyses revealed no significant differences.

CONCLUSIONS

Three genetic risk factors established in Caucasian patients are not valuable for evaluating DVT risk in Japanese patients. Reduced protein C activity may be a risk factor for DVT after THA.

The influence of risk factors in promoting thrombosis during childhood: the role of acquired factors

Thrombo-embolism in childhood is a multifactorial disorder. The present study is a case-control study that investigated the role of genetic and acquired risk factors in 60 children with thrombosis and compared the results with the controls. Acquired and inherited risk factors precipitating thrombosis were present in 75 and 40% of the thrombotic children, respectively. The most frequent acquired risk factor was infection (58%). Of the genetic factors, factor V G20210A was the most common (38%). The comparison of the genetic and acquired risk factors in thrombotic versus nonthrombotic settings identified that acquired factors played a more significant role in causing thrombosis (OR:14.44; 95% CI: 7.05-29.94, p < .001). This study has clearly suggested that the prevention of acquired risk factors, particularly infection, could decrease the risk of thrombosis in pediatric cases.

A Case Control Study on the Contribution of Factor V-Leiden, Prothrombin G20210A, and MTHFR C677T Mutations to the Genetic Susceptibility of Deep Venous Thrombosis

BACKGROUND

Insofar as the inherited prothrombotic single nucleotide polymorphisms (SNPs) factor V G1691A (FV-Leiden), prothrombin (PRT) G20210A, and methylenetetrahydrofolate reductase (MTHFR), C677T are inherited risk factors of venous thromboembolism (VTE), the aim of this study was to determine the prevalence of single and combined SNPs in 198 patients with documented deep venous thrombosis (DVT), and 697 control subjects, and to estimate the associated risks.

METHODS

Factor V-Leiden, PRT G20210A, and MTHFR C677T were analyzed by PCR and restriction fragment length polymorphism (RFLP).

RESULTS

The prevalence of the heterozygote and homozygous variants for FV-Leiden (52.02 vs. 14.78%, RR 6.28), PRT G20210A (19.2 vs. 3.6%; RR 6.38), and to a lesser extent the T/T genotype of MTHFR C677T (20.71 vs. 11.0%; RR 1.49) were higher among DVT patients vs. controls, respectively. Two or more SNPs were detected in 90 of 198 patients (45.5%) and in 60 of 697 controls (8.6%), with odds ratios of 16.754 for joint occurrence of FV-Leiden and PRT G20210A, 10.471 for FV-Leiden and MTHFR C677T, and 6.283 for PRT G20210A SNPs and MTHFR 677T/T. Logistic regression analysis showed a further increased odds for FV-Leiden in combination with PRT G20210A (85.198) or homozygous MTHFR C677T (81.133), and to a lesser extent for PRT G20210A in combination with homozygous MTHFR C677T (20.812).

CONCLUSIONS

This indicates that FV-Leiden and PRT G20210A, more than MTHFR C677T, are important risk factors for DVT, and that the presence of more than one prothrombotic SNPs was associated with a significant risk of DVT.

Homocysteine, MTHFR and risk of venous thrombosis: a meta-analysis of published epidemiological studies

CONTEXT

It has been suggested that elevated total plasma homocysteine levels are associated with the risk of venous thrombosis.

OBJECTIVE

To assess the relationship of homocysteine and the MTHFR 677TT genotype and the risk of venous thrombosis by conducting a meta-analysis of all relevant studies.

DATA SOURCES AND SELECTION

Studies (case-control or nested case-control) were identified by searches of electronic literature for relevant reports published before July 2003 on homocysteine and the MTHFR 677TT genotype and venous thrombosis as an end-point, by hand-searching reference lists of original articles (including meta-analyses) on this topic and by contact with investigators in the field.

DATA EXTRACTION

A meta-analysis of 24 retrospective (n = 3289 cases) and three prospective studies (n = 476 cases) was carried out to examine the association of homocysteine with venous thrombosis. A meta-analysis of 53 studies (n = 8364 cases) of the MTHFR 677TT genotype (that increases homocysteine) was carried out to assess if this association is causal.

DATA SYNTHESIS

A 5 micromol L(-1) higher measured homocysteine level was associated with a 27% (95% CI: 1-59) higher risk of venous thrombosis in prospective studies and a 60% (95% CI: 10-134) higher risk in retrospective studies. The 677TT genotype was associated with a 20% (95% CI: 8-32) higher risk of venous thrombosis compared with the 677CC genotype. In contrast with non-American studies, the 677TT genotype had no effect on venous thrombosis in North America, due probably to the higher intake of folate and riboflavin in North America.

CONCLUSION

This meta-analysis of prospective and retrospective studies demonstrates a modest association of homocysteine with venous thrombosis. The elevated risk associated with the MTHFR 677TT genotype provides some support for causality.

Rapid combined genotyping of factor V, prothrombin and methylenetetrahydrofolate reductase single nucleotide polymorphisms using minor groove binding DNA oligonucleotides (MGB probes) and real-time polymerase chain reaction

Risk factors for cardiovascular diseases and venous thromboembolism involve both acquired and hereditary conditions. Among the latter, mutations in genes coding for coagulation factors (

[A common mutation C677T in the 5,10-methyltetrahydrofolate reductase gene is associated to idiopathic deep venous thrombosis]

PURPOSE

Moderate hyperhomocysteinemia is a risk factor for deep venous thrombosis. The homozygous C677T methylenetetrahydrofolate reductase (MTHFR) mutation is associated with increased level of total plasma homocysteine. The association between homozygous C677T mutation and deep venous thrombosis is still controversial.

METHOD

In order to evaluate this association, we studied the prevalence of C677T mutation in 168 patients with confirmed deep venous thrombosis; 31 with an idiopathic deep venous thrombosis (group A) and 137 with thromboembolic event explained by one or more clinical and/or biological risk factors (group B).

RESULTS

The distribution of genotypes was different between group A and B [++/+ -/- -(n(%))] : 9(29)/10(32)/12(39) vs 16(12)/57(42)/64(46) (chi(2) : 6.03; P: 0.049). The comparison between homozygotes and the two other genotypes showed significant statistical relationship between homozygous genotype and idiopathic character of deep venous thrombosis (chi(2) : 6.01; P : 0.014; OR : 3.09 [IC 95% : 1.06-8.53]).

CONCLUSION

These results suggest that homozygous C677T methylenetetrahydrofolate reductase mutation could be considered as a genetic risk factor for venous thrombosis.

Serum homocysteine, thermolabile variant of methylene tetrahydrofolate reductase (MTHFR), and venous thromboembolism: Longitudinal Investigation of Thromboembolism Etiology (LITE)

We sought to examine prospectively the association of serum homocysteine and the methylene tetrahydrofolate reductase (MTHFR) C677T gene polymorphism with risk of venous thromboembolism (VTE). We studied these relationships in a nested case-control study of 303 VTE cases and 635 matched controls from a population-based cohort of 21,680 adults from six U.S. communities. The highest quintile of serum homocysteine carried a non-statistically significant adjusted odds ratio of 1.55 (95% CI, 0.93-2.58) compared to the lowest quintile in the overall cohort but a significant association among adults aged 45-64 years (OR = 2.05, 95% CI, 1.10-3.83) and an inverse association in those > or = 65 years of age. Carriers of the MTHFR C677T polymorphism were not at higher risk for VTE than those with normal genotype (OR = 0.74, 95% CI = 0.56-0.98). Our prospective data showed, at most, a weak relationship between homocysteine and VTE risk, with associations larger among younger participants. MTHFR C677T was not a risk factor for VTE.

Major and potential prothrombotic genotypes in a cohort of patients with venous thromboembolism

Factor V Leiden (FVL) and the prothrombin 20210A (PT-20210A) variant are well-known risk factors for venous thromboembolism (VT). The thermolabile variant (TT) of the methylenetetrahydrofolate reductase (MTHFR) gene, and homozygosity for the 4G allele of the promoter region of the plasminogen activator inhibitor-1 (PAI-1) are potential genetic polymorphisms that have not been consistently associated with increased risk of VT. A case-control study was performed on 192 consecutive unrelated patients referred for evaluation of thrombophilia because of VT and 200 healthy controls. FVL was found in 10.4% of patients compared to 3.0% of controls, while 6.3% of patients were carriers of the PT-20210A allele compared to 2.0% of controls. The adjusted odds ratios (OR) were 5.92 and 4.03 for FVL (P=.001) and the PT-20210A (P=.033), respectively. The prevalence of homozygotes for MTHFR (TT) and PAI-1 (4G/4G) among patients and controls were 13.7% versus 13.0% and 21.6% versus 23.5%, respectively (P=ns). A total of 121 patients underwent a complete screening for FVL, the PT-20210A, protein C (PC), protein S (PS), antithrombin III (ATIII), levels of factor VIII, and antiphospholipid antibodies (aPL). In 59 patients (48.8%) at least one defect was found, being a single defect in 55 and combined defects in 4 patients. Plasma levels of homocysteine (Hcy) were measured in 138 patients and 144 controls. Subjects from both groups carrying the MTHFR-TT variant had higher Hcy levels than those with the normal genotype. Hyperhomocysteinemia (HHcy) by itself is a risk factor for VT (OR 4.92, P<.0001). We conclude that FVL and the PT-20210A are risk factors for VT as well as Hcy levels, but the MTHFR and PAI-1 polymorphisms do not appear to be associated with VT in our country.

Importance of hyperhomocysteinemia as a risk factor for venous thromboembolism in a Taiwanese population. A case-control study

OBJECTIVE

To determine the current status of hyperhomocysteinemia, which is a known risk for venous thrombosis (DVT), in Taiwan.

SUBJECTS

101 unselected patients with a minimum of one episode of deep leg DVT, either initial inpatients or current compliant outpatients in a teaching hospital.

METHODS

Various thrombophilic risks, gene polymorphism and clinical predisposition were evaluated.

RESULTS AND CONCLUSIONS

Patients presented higher fast total plasma homocysteine (hcy) levels than age- and sex-matched controls did (14.1 vs. 9.94 microM). Based on the 95th percentile of control values, hyperhomocysteinemia had a four- to nine-fold risk for DVT, irrespective of clinical predisposition, as well as other thrombophilic risks surveyed. Polymorphism of a metabolizing enzyme, methylenetetrahydrofolate reductase (MTHFR), was not associated with DVT, although homozygous thermolabile mutation tended to have higher plasma hcy levels. Factor V Leiden was absent in analysis of 80 patients. In complete evaluation (hcy, antithrombin (AT), protein S (PS), protein C (PC), lupus anticoagulant (LA), anticardiolipin antibody) of a subset of 83 patients hyperhomocysteinemia was the most prevalent risk (33.7%), with PC or PS deficiencies following (22.9%). Thus, hyperhomocysteinemia is a prominent risk for DVT in Taiwan.

Association between polymorphisms of folate- and methionine-metabolizing enzymes and susceptibility to malignant lymphoma

Genetic alteration is considered a probable cause of malignant lymphoma. Folate and methionine metabolism play essential roles in DNA synthesis and DNA methylation, and their metabolic pathways might thus affect disease susceptibility. In the present study, 2 polymorphisms were evaluated for a folate metabolic enzyme, methylenetetrahydrofolate reductase (MTHFR), and one was evaluated for methionine synthase (MS). The 2 polymorphisms, MTHFR677 C-->T and MTHFR1298 A-->C, are reported to reduce the enzyme activity, which causes intracellular accumulation of 5,10-methylenetetrahydrofolate and results in a reduced incidence of DNA double-strand breakage. The MS2756 A-->G polymorphism also reduces the enzyme activity and results in the hypomethylation of DNA. To evaluate the association between malignant lymphoma susceptibility and these polymorphisms, hospital-based case-control study was conducted in Aichi Cancer Center. Ninety-eight patients with histologically confirmed lymphoma and 243 control subjects without cancer were evaluated. Unconditional logistic regression analyses revealed a higher susceptibility with the MTHFR677 CC and the MTHFR1298 AA genotypes (odds ratio, 2.26; 95% confidence interval, 1.26-4.02) when those harboring at least one variant allele in either polymorphism of MTHFR were defined as the reference. For the MS polymorphism, the MS2756 GG genotype also showed a higher susceptibility (odds ratio, 3.83; 95% CI, 1.21-12.1) than those with MS2756 AA or AG types. The significance was not altered when these 3 polymorphisms were evaluated in combination, and the results suggest that folate and methionine metabolism play important roles in the occurrence of malignant lymphomas. Further studies to confirm the association and detailed biologic mechanisms are now required.