Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.5.7.1 (methylenetetrahydrofolate reductase)
2,116 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inherited thrombophilias are the leading cause of maternal thromboembolism and are associated with an increased risk of certain adverse pregnancy outcomes including second- and third-trimester fetal loss, abruptions, severe intrauterine growth restriction, and early-onset, severe preeclampsia. Current information suggests that all patients with a history of prior venous thrombotic events and those with these characteristic adverse pregnancy events should be evaluated for thrombophilias. The most common, clinically significant, inherited thrombophilias are heterozygosity for the factor V Leiden and prothrombin G20210A mutations. The autosomal-dominant deficiencies of protein C and protein S are of comparable thrombogenic potential but are far less common. Homozygosity for the 4G/4G mutation in the type-1 plasminogen activator inhibitor gene and the thermolabile variant of the methylenetetrahydrofolate reductase gene, the leading cause of hyperhomocysteinemia, although relatively common, confer a low risk of thrombosis. In contrast, autosomal-dominant antithrombin deficiency and homozygosity or compound heterozygosity (ie, carriers of one copy of each mutant allele) for the factor V and prothrombin mutations are very rare but highly thrombogenic states. Regardless of their antecedent histories, pregnant patients with these highly thrombogenic conditions are at very high risk for both thromboembolism and characteristic adverse pregnancy outcomes, require full therapeutic heparin therapy throughout pregnancy, and need at least 6 weeks of postpartum oral anticoagulation. There is also compelling evidence that patients with the less thrombogenic thrombophilias and a history of venous thrombotic events or characteristic adverse pregnancy outcomes require prophylactic anticoagulant therapy during pregnancy and, in the case of prior thromboembolism, during the puerperium. Antepartum anticoagulation does not appear warranted among patients with less thrombogenic thrombophilias who are without a history of venous thromboembolism, characteristic adverse pregnancy outcomes, or other high risk factors for venous thrombosis.
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PMID:Inherited thrombophilias in pregnant patients: detection and treatment paradigm. 1181 16

Abdominal aortic aneurysm (AAA) presents itself as a progressive dilation of the abdominal aorta, leading--if untreated--to rupture. It is a common disease of the elderly, with a complex etiology. Several genetic, biochemical and environmental factors are recognized as relevant for the pathogenesis of AAA. We determined the polymorphism of the MTHFR (methylenetetrahydrofolate reductase) gene within the fourth exon (C677T) in 63 patients with AAA and compared it to that in 75 subjects of the population sample. The frequencies of the C/C, C/T and T/T genotypes were 65%, 27%, and 8% in the population sample and 33%, 60%, and 6% in the patients. This corresponds to a 4.4-fold greater risk of AAA in subjects who have the 677C/T variant of MTHFR, as compared with those who are 677C/C (p < 0.0001; 95% CI=2.11-9.34). The frequency of allele MTHFR 677T in patients (0.37) was higher than in the population sample (0.21; p < 0.007). This association between the common allele of the MTHFR gene--MTHFR 677T--and the development of AAA suggests that elevated homocysteine (Hcy) may disturb the function of the aortic wall. The disturbance may involve enhancement of elastin degradation, the process enhanced by mild hyperhomocysteinemia in minipigs. The magnitude of this effect, which refers to the AAA patients unselected for familial occurrence, indicates that the disturbance of aortic wall physiology caused by the presence of the MTHFR 677T allele is greater than the effect of the earlier described allele disequilibrium at the polymorphic alleles of the PAI1 (plasminogen activator inhibitor 1) gene seen only in familial cases of AAA.
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PMID:Increased risk of the abdominal aortic aneurysm in carriers of the MTHFR 677T allele. 1259 Jan 85

Hemostatic gene polymorphisms have been shown to be associated with arterial and venous thrombotic disease. To date these polymorphisms have mainly been detected by labor-intensive conventional gel based methods. Aim of the present study was to design and optimize high throughput 5' nuclease assays for the detection of a set of 10 single-nucleotide polymorphisms (SNP) in genes of importance for hemostasis: plasminogen activator inhibitor type 1 -675 4G>5G, thrombin activatable fibrinolysis inhibitor Ala147Thr and 1,542C>G, beta-fibrinogen -455G>A, von Willebrand factor -1,051A>G, factor VII Arg353Gln, factor XIII Val34Leu, prothrombin 20,210G>A, tissue factor pathway inhibitor -287T>C, and methylenetetrahydrofolate reductase 1,298A>C. Specificity of each genotyping assay was confirmed by sequence-based typing and reproducibility was evaluated by repeated genotyping. The genotyping protocols presented here may serve as a valuable tool for clinical researchers interested in exploring associations between these SNPs and thrombotic disease.
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PMID:Rapid genotyping of haemostatic gene polymorphisms using the 5' nuclease assay. 1271 92

Our specific aim was to assess associations of thrombophilia, hypofibrinolysis, and polycystic ovary syndrome (PCOS) with recurrent pregnancy loss (RPL) (>/=3 consecutive pregnancy losses < 20 weeks gestation). Prospective studies were performed in 33 Caucasian women referred for diagnosis and treatment of PCOS who were subsequently found to have RPL and in 16 Caucasian women referred for diagnosis and treatment of RPL, who did not have PCOS. Cases (PCOS-RPL, RPL without PCOS) were compared with controls (116 healthy Caucasian females) for the G1691A Factor V Leiden, G20210A prothrombin, C677T methylenetetrahydrofolate reductase (MTHFR), plasminogen activator inhibitor 4G/5G, and platelet glycoprotein PL A1A2 gene mutations. Cases were compared with controls (44 healthy adult Caucasian females) for serologic coagulation tests including homocysteine, proteins C, S, free S, antithrombin III, anticardiolipin antibodies IgG and IgM, dilute Russel's viper venom time, activated partial thromboplastin time, Factor VIII, Factor XI, lipoprotein (Lp)(a), and plasminogen activator inhibitor activity (PAI-Fx). The 33 Caucasian women with PCOS subsequently found to have RPL were 10% of a cohort of 322 Caucasian women who had >/= 1 previous pregnancy and had been referred for diagnosis and therapy of PCOS over a 4.3-year period. The Factor V Leiden G1691 mutation was present in 6 of 33 women (18%) with PCOS-RPL and in 3 of 16 women with RPL without PCOS (19%) versus 2 of 116 (1.7%) female controls, Fisher's P (p(f)) =.0016, p(f) =.013. The 33 PCOS-RPL cases also differed from the 44 female controls for high PAI-Fx (>21.1 U/mL), 38% versus 8%, p(f) =. 004. The thrombophilic G1691A Factor V Leiden mutation is associated with RPL in women with and without PCOS; hypofibrinolysis (high PAI-Fx) is also associated with RPL in women with PCOS.
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PMID:Polycystic ovary syndrome, the G1691A factor V Leiden mutation, and plasminogen activator inhibitor activity: associations with recurrent pregnancy loss. 1466 68

A multi-site study to assess the accuracy and performance of the biplex Invader assay for genotyping five polymorphisms implicated in venous thrombosis was carried out in seven laboratories. Genotyping results obtained using the Invader biplex assay were compared to those obtained from a reference method, either allele-specific polymerase chain reaction (AS-PCR), restriction fragment length polymorphism (PCR-RFLP) or PCR-mass spectrometry. Results were compared for five loci associated with venous thrombosis: Factor V Leiden, Factor II (prothrombin) G20210A, methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, and plasminogen activator inhibitor (PAI-1) 4G/5G. Of a total of 1448 genotypes tested in this study, there were 22 samples that gave different results between the Invader biplex assay and the PCR-based methods. On further testing, 21 were determined to be correctly genotyped by the Invader Assay and only a single discrepancy was resolved in favor of the PCR-based assays. The compiled results demonstrate that the Invader biplex assay provides results more than 99.9% concordant with standard PCR-based techniques and is a rapid and highly accurate alternative to target amplification-based methods.
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PMID:Detection of genomic polymorphisms associated with venous thrombosis using the invader biplex assay. 1509 70

Recently, it has been proposed that abnormalities in coagulation and fibrinolysis contribute to the development of preeclampsia by increasing the thrombotic tendency. This hypothesis was tested in women who have had preeclampsia (cases) compared with matched controls. Polymorphisms in the thrombophilia genes [plasminogen activator inhibitor type 1 [PAI-1 -675(4G/5G)], thrombin activatable fibrinolysis inhibitor (TAFI -438G/A and 1040C/T), methylenetetrahydrofolate reductase (MTHFR 677C/T), factor V (FV Leiden R/Q506), prothrombin (FII 20210G/A) and factor XIIIA (FXIIIA V/L34)] were determined in 157 women with preeclampsia and 157 women with uncomplicated pregnancy. The associated risk of preeclampsia was analyzed using logistic regression methods. The frequency distributions of the genotypes of these six polymorphisms in thrombophilia genes were similar in the case and control groups. We found no differences in the prevalence of genetic risk factors of thrombosis in women with preeclampsia compared with controls, which makes it unlikely that these polymorphisms are risk factors for preeclampsia.
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PMID:Preeclampsia and its interaction with common variants in thrombophilia genes. 1533 35

A kindred was examined in which the 48-year-old white female proband with three deep venous thrombosis-pulmonary emboli events had four thrombophilic and one hypofibrinolytic mutations, and in which her 14-year-old asymptomatic daughter had four thrombophilic mutations. The proband was heterozygous for the G1691A factor V Leiden, G20210A prothrombin, and platelet glycoprotein IIIa PL A1/A2 mutations, had high factor VIII (221%), and was homozygous for the 4G4G plasminogen activator inhibitor-1 gene mutation, with high plasminogen activator inhibitor activity (23.7 U/mL). Her 14-year-old daughter was homozygous for the G1691A factor V Leiden and platelet glycoprotein IIb-IIIa PL A2/A2 mutations, compound heterozygous for the C677T and A1298C methylenetetrahydrofolate reductase (MTHFR) mutations, and heterozygous for the G20210A prothrombin mutation, a combination with an estimated likelihood of 1.6 x 10(-7). In 247 white healthy controls, there was no V Leiden homozygosity and no V Leiden-prothrombin gene compound heterozygosity. Heterozygosity for the V Leiden and prothrombin gene mutations was 3.2% and 4.1%, respectively. Homozygosity for the platelet glycoprotein IIb-IIIa PL A2A2, PAI-1 gene 4G4G, and C677T MTHFR mutations was 3.2%, 22.7%, and 12%, respectively. The proband will receive anticoagulation therapy for life. Beyond aspirin, avoidance of exogenous estrogens, and enoxaparin prophylaxis during pregnancy, it is not known whether the proband's daughter should have lifelong anticoagulation therapy, or only after her first thrombotic event.
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PMID:Ramifications of four concurrent thrombophilic mutations and one hypofibrinolytic mutation. 1549 23

Recently, several investigations concerning disadvantageous genetic factors in human reproduction have progressed. Inherited thrombophilia, such as factor V Leiden, prothrombin, and methylenetetrahydrofolate reductase mutations; gene polymorphisms of detoxification enzyme (CYP1A1); growth factors (insulin-like growth factor-I); and hormones such as angiotensinogen and CYP17 are involved in the pathogenesis of fetal growth restriction. The inherited thrombophilia, gene polymorphisms of coagulation and anticoagulation factor such as thrombomodulin, endothelial protein C receptor, plasminogen activator inhibitor 1, and factor XIII; human lymphocyte antigen (HLA-G); detoxification enzymes (glutathione- S-transferase M1); cytokines such as interleukin (IL) -1 and IL-6; hormones (CYP17); vasodilators (nitric oxide synthase 3); and vitamins (transcobalamin) are involved in the pathogenesis of sporadic and recurrent miscarriage. It is likely that a gene polymorphism or mutation susceptible to reproductive failure has a beneficial effect on the process of human reproduction with or without the environmental interaction. The factor V Leiden mutation has genetic advantages that are believed to be an improved implantation rate in in vitro fertilization and a reduction of maternal intrapartum blood loss. It has also been demonstrated that the CYP17 A2 allele has bidirectional effects on human reproduction, including increases in susceptibility to recurrent miscarriage and fetal growth enhancement.
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PMID:Genetic factors in fetal growth restriction and miscarriage. 1605 6

The purpose of this study was to evaluate the thrombophilic genes in pregnant women with and without preeclampsia independently or in combination. In a prospective case-control study, we investigated four polymorphisms in thrombophilic genes in 75 women with mild or severe preeclampsia and 145 women with normal pregnancy. The genotype frequencies were assessed and the odds ratio (OR) calculated. When we analyzed the polymorphisms independently and the development of preeclampsia, no association was observed [methylenetetrahydrofolate reductase (MTHFR) 677TT genotype, OR 2.07, 95% confidence interval (CI) 0.99-4.30; prothrombin mutation (F II) (GA or AA genotypes) OR 8.11, 95% CI 0.89-73.92; factor V Leiden (FV Leiden) OR 3.94, 95% CI 0.35-44.23; plasminogen activator inhibitor (PAI-1) 4G/4G genotype, OR 1.63, 95% CI 0.87-3.05] not even with severe preeclampsia subgroup analysis. However, when we investigated a possible interaction among these polymorphisms on the development of the preeclampsia, the OR for having one risk genotype, one or two genotype risk factors and two genotype risk factors compared to those without genotype risk factors were 1.97 (95% CI 1.08-3.59), 2.21 (95% CI 1.25-3.92) and 4.27 (95% CI 1.3-13.9), respectively. In conclusion, in the population analyzed, the presence of the genotype risk factors alone does not seem to be associated with the development of preeclampsia even in the severe presentation form. However, an interaction among the MTHFR, F II, FV and PAI-1 gene polymorphisms on the development of the preeclampsia was indicated.
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PMID:Relationship between polymorphisms in thrombophilic genes and preeclampsia in a Brazilian population. 1696 92

Evolvement and progression of cardiovascular diseases affecting the venous and arterial system are influenced by a multitude of environmental and hereditary factors. Many of these hereditary factors consist of defined gene polymorphisms, such as single nucleotide polymorphisms (SNPs) or insertion-deletion polymorphisms, which directly or indirectly affect the hemostatic system. The frequencies of individual hemostatic gene polymorphisms in different normal populations are well defined. However, descriptions of patterns of genetic variability of a larger extent of different factors of hereditary hypercoagulability in single populations are scarce. The aim of this study was i) to give a detailed description of the frequencies of factors of hereditary thrombophilia and their combinations in a German population (n = 282) and ii) to compare their distributions with those reported for other regions. Variants of coagulation factors [factor V 1691G>A (factor V Leiden), factor V 4070A>G (factor V HR2 haplotype), factor VII Arg353Gln, factor XIII Val34Leu, beta-fibrinogen -455G>A, prothrombin 20210G>A], coagulation inhibitors [tissue factor pathway inhibitor 536C>T, thrombomodulin 127G>A], fibrinolytic factors [angiotensin converting enzyme intron 16 insertion/deletion, factor VII-activating protease 1601G>A (FSAP Marburg I), plasminogen activator inhibitor 1-675 insertion/deletion (5G/4G), tissue plasminogen activator intron h deletion/insertion], and other factors implicated in influencing susceptibility to thromboembolic diseases [apolipoprotein E2/E3/E4, glycoprotein Ia 807C>T, methylenetetrahydrofolate reductase 677C>T] were included. The distribution of glycoprotein Ia 807C>T deviated significantly from the Hardy-Weinberg equilibrium, and a comparison with previously published data indicates marked region and ethnicity dependent differences in the genotype distributions of some other factors.
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PMID:Gene polymorphisms implicated in influencing susceptibility to venous and arterial thromboembolism: frequency distribution in a healthy German population. 1700 23


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