Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
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Single-nucleotide polymorphisms in the genes that code for coagulation factors V (factor V Leiden) and II (prothrombin, G20210A), as well as the methylenetetrahydrofolate reductase (MTHFR, C677T) gene, have been implicated in the majority of cases of hereditary thrombophilia. We have developed a multiplex PCR-RFLP assay based on MnlI endonuclease digestion for the simultaneous detection of mutations in the FV, FII, and MTHFR genes. Digested amplification products were analyzed by gel electrophoresis in a single gel lane and visualized by ethidium bromide. This approach is a rapid and convenient method, hence economic, that alternate to others described for the detection of FVL, G20210A and C677T mutations.
Exp Mol Pathol 2007 Aug
PMID:Primer-engineered multiplex PCR-RFLP for detection of MTHFR C677T, prothrombin G20210A and factor V Leiden mutations. 1727 7

The goals of our present study were to measure plasma homocysteine levels and determine their association with methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms (C677T and A1298C) in essential hypertensive subjects. Plasma total homocysteine and folic acid levels were measured in essential hypertensive patients (n = 153) before and after oral supplementation with either 5 mg folic acid tablet/day or 5 mg placebo/day for 4 weeks and compared with age and sex matched normotensive controls (n = 133). MTHFR gene polymorphisms (C677T and A1298C) were studied by restriction fragment length polymorphism and correlated with plasma homocysteine levels. Homocysteine levels were significantly higher in hypertensive patients as compared to controls and showed a negative correlation with plasma folate levels. Folic acid supplementation (5 mg/day) for 4 weeks resulted in a significant decrease in plasma homocysteine concentrations in these patients. Patients carrying MTHFR 677T allele (OR = 1.90; 95%CI: 1.14-3.19) or MTHFR 1298C (OR = 2.6, 95%CI: 1.55-4.40) allele were at increased risk of hypertension. The frequency of co-occurrence of MTHFR 677 CT/1298 CC genotypes was significantly higher in the patients compared to controls (P < 0.05) and was associated with increased risk of hypertension (OR = 3.54, 95%CI: 0.37-4.30). Subjects with MTHFR 1298 CC genotype had significantly higher homocysteine levels compared to those with MTHFR 1298 AA genotype (P < 0.05). Our results indicate that MTHFR 677T and 1298C alleles and co-occurrence of MTHFR 677 CT/MTHFR 1298 CC genotypes are associated with increased risk of hypertension and MTHFR 1298 CC genotype is associated with higher homocysteine levels in our subjects.
Mol Cell Biochem 2007 Aug
PMID:MTHFR 677 CT/MTHFR 1298 CC genotypes are associated with increased risk of hypertension in Indians. 1733 88

We studied 692 Swedish children and adolescents (aged 9-10 or 15-16 years, respectively), in order to evaluate the effect of the methylenetetrahydrofolate reductase (MTHFR) 677C>T, 1298A>C, and 1793G>A polymorphisms on total plasma homocysteine concentrations (tHcy). Genotyping was performed with Pyrosequencing technology. The MTHFR 677C>T polymorphism was associated with increased tHcy concentrations in both the children and the adolescents (P<0.001 for both age groups) in both genders. The effect of MTHFR 1298A>C was studied separately in subjects with the 677CC and 677CT genotypes, and the 1298C allele was found to be associated with higher tHcy levels both when children were stratified according to 677C>T genotypes, and when using haplotype analyses and diplotype reconstructions. The 1793A allele was in complete linkage disequilibrium with the 1298C allele. It was still possible to show that the 1793A allele was associated with lower tHcy levels, statistically significant in the adolescents. In conclusion, a haplotype-based approach was slightly superior in explaining the genetic interaction on tHcy plasma levels in children and adolescents than a simple genotype based approach (R2 adj 0.44 vs. 0.40). The major genetic impact on tHcy concentrations is attributable to the MTHFR 677C>T polymorphism. The common 1298A>C polymorphism had a minor elevating effect on tHcy, whereas the 1793G>A polymorphism had a lowering effect on tHcy.
Int J Mol Med 2007 Apr
PMID:Association of total plasma homocysteine with methylenetetrahydrofolate reductase genotypes 677C>T, 1298A>C, and 1793G>A and the corresponding haplotypes in Swedish children and adolescents. 1733 42

Over a four-year period, we collected clinical and biochemical data from five Amish children who were homozygous for missense mutations in 5,10-methylenetetrahydrofolate reductase (MTHFR c.1129C>T). The four oldest patients had irreversible brain damage prior to diagnosis. The youngest child, diagnosed and started on betaine therapy as a newborn, is healthy at her present age of three years. We compared biochemical data among four groups: 16 control subjects, eight heterozygous parents, and five affected children (for the latter group, both before and during treatment with betaine anhydrous). Plasma amino acid concentrations were used to estimate changes in cerebral methionine uptake resulting from betaine therapy. In all affected children, treatment with betaine (534+/-222 mg/kg/day) increased plasma S-adenosylmethionine, improved markers of tissue methyltransferase activity, and resulted in a threefold increase of calculated brain methionine uptake. Betaine therapy did not normalize plasma total homocysteine, nor did it correct cerebral 5-methyltetrahydrofolate deficiency. We conclude that when the 5-methyltetrahydrofolate content of brain tissue is low, dietary betaine sufficient to increase brain methionine uptake may compensate for impaired cerebral methionine recycling. To effectively support the metabolic requirements of rapid brain growth, a large dose of betaine should be started early in life.
Mol Genet Metab 2007 Jun
PMID:Prevention of brain disease from severe 5,10-methylenetetrahydrofolate reductase deficiency. 1740 6

We have examined the prevalence of the C677T and A1298C single nucleotide polymorphisms (SNPs) in the methylenetetrahydrofolate reductase (MTHFR) gene in healthy Tamilians and in patients with acute myocardial infarction and related this polymorphism to plasma homocysteine concentrations, serum folate, serum cobalamin and riboflavin status. The SNPs in the MTHFR gene were determined by polymerase chain reaction-restriction fragment length polymorphism analysis. Plasma homocysteine, serum folate and serum cobalamin concentrations were analyzed using an automated chemiluminescence method and riboflavin status was assessed by measuring the erythrocyte glutathione reductase activity using spectrophotometric method. Out of the 200 young and middle-aged (<48 years) individuals included in the study, 100 were acute myocardial infarction (AMI) patients and 100 were healthy individuals with no documented history of heart diseases. There was a significant increase in homocysteine levels among the AMI patients as compared to the healthy controls (p<0.001). The results of this study indicate that hyperhomocystinemia is more prevalent in Tamilian AMI patients and that the MTHFR C677T and A1298C SNPs are not associated with hyperhomocystinemia. Folate status was found to be within normal range in all the study subjects. There was no correlation between homocysteine and different biochemical variables including cobalamin, folate and riboflavin. However, serum cobalamin was found to be significantly decreased in AMI patients when compared to controls (p<0.001). The simultaneous presence of decreased serum cobalamin status, hyperhomocystinemia and mutant genotype for both the SNPs might lead to an increased risk for the occurrence of AMI. Further intervention trials including the supplementation of cobalamin may prove whether homocysteine level decrease in response to the supplementation of cobalamin in individuals with hyperhomocystinemia and mutant genotype for both the above mentioned SNPs.
Exp Mol Pathol 2007 Jun
PMID:MTHFR Gene polymorphisms, B-vitamins and hyperhomocystinemia in young and middle-aged acute myocardial infarction patients. 1741 21

Amplicon melting is a closed-tube method for genotyping that does not require probes, real-time analysis, or allele-specific polymerase chain reaction. However, correct differentiation of homozygous mutant and wild-type samples by melting temperature (Tm) requires high-resolution melting and closely controlled reaction conditions. When three different DNA extraction methods were used to isolate DNA from whole blood, amplicon Tm differences of 0.03 to 0.39 degrees C attributable to the extractions were observed. To correct for solution chemistry differences between samples, complementary unlabeled oligonucleotides were included as internal temperature controls to shift and scale the temperature axis of derivative melting plots. This adjustment was applied to a duplex amplicon melting assay for the methylenetetrahydrofolate reductase variants 1298A>C and 677C>T. High- and low-temperature controls bracketing the amplicon melting region decreased the Tm SD within homozygous genotypes by 47 to 82%. The amplicon melting assay was 100% concordant to an adjacent hybridization probe (HybProbe) melting assay when temperature controls were included, whereas a 3% error rate was observed without temperature correction. In conclusion, internal temperature controls increase the accuracy of genotyping by high-resolution amplicon melting and should also improve results on lower resolution instruments.
J Mol Diagn 2007 Jul
PMID:Unlabeled oligonucleotides as internal temperature controls for genotyping by amplicon melting. 1759 26

The disorders of folate metabolism caused by methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms may lead to several disease states including coronary heart disease, venous thrombosis, and several types of cancer. We have developed a real-time multiplex single-tube polymerase chain reaction procedure on the LightCycler for the detection of the two most commonly occurring variants, 677C>T and 1298A>C, in the MTHFR gene. An improved probe design, based on the nearest neighbor model for nucleic acid-probe duplex stability, resulted in a better separation (DeltaTm approximately 10 degrees C) of melting peaks of the wild-type and mutant alleles than that by the existing method (DeltaTm approximately 3 degrees C) for specimens heterozygous for the 1298A>C polymorphism. Of the 333 blood specimens analyzed by this procedure, we did not find any samples that gave ambiguous results. The specimens with homozygous mutation for one polymorphism were of the wild type for the other variant. The assay was validated by the comparison of the genotyping results of 50 blood specimens from the LightCycler polymerase chain reaction with the conventional restriction fragment length polymorphism procedures. There was 100% concordance of the test results obtained by the two techniques. This assay is reliable, economical, and can be performed by less trained technologists compared with the procedure performed by the conventional restriction fragment length polymorphism technique.
J Mol Diagn 2007 Jul
PMID:Improved real-time multiplex polymerase chain reaction detection of methylenetetrahydrofolate reductase (MTHFR) 677C>T and 1298A>C polymorphisms using nearest neighbor model-based probe design. 1759 34

Previous studies have suggested that both angiotensin II type-1 receptor (AT1R) 1166C and methylenetetrahydrofolate reductase (MTHFR) 677T variants can have disadvantageous effects on the small-vessel circulation under certain conditions. The purpose of this study was to analyze the possible consequences of the simultaneous distribution of these two genetic variants in different types of ischemic stroke. The genetic and clinical data on 357 ischemic stroke patients and 263 control subjects were analyzed by using univariate and logistic statistical approaches. Neither the MTHFR 677T nor the AT1R 1166C genetic variant alone conferred the risk of any subtype of ischemic stroke. The combination of the homozygous MTHFR 677TT genotype and at least one AT1R 1166C allele occurred more frequently in the ischemic stroke patients (8.68%) than in the controls (4.56%, p < 0.05). Specific subclassification of the patients revealed an accumulation of this combination in small-vessel-associated ischemic stroke (12.2%, p < 0.01); multivariate logistic regression analysis of the data confirmed this association, with an odds ratio of 2.66 (95% confidence interval, 1.28-7.89; p < 0.05). These findings suggest that the combination of these two genetic factors can contribute to the development of small-vessel cerebral infarcts. Although the exact mechanism of action is not known, addition of the unfavourable effects on the endothelial function can be presumed.
J Mol Neurosci 2007
PMID:The combination of homozygous MTHFR 677T and angiotensin II type-1 receptor 1166C variants confers the risk of small-vessel-associated ischemic stroke. 1772 26

The methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism has been shown to be associated with cardiovascular disease and in patients with end-stage renal disease (ESRD). However, the relationship between MTHFR polymorphisms and cardiovascular disease (CVD) in patients on hemodialysis has not been examined. The aim of this study was to assess the association of polymorphisms of MTHFR gene with homocysteine (Hcy) and intimal medial thickness (IMT) in patients on hemodialysis. We performed case-control study involving107 patients with ESRD and 103 healthy controls. Plasma Hcy was measured in all the subjects and these subjects were genotyped for three MTHFR polymorphisms (C677T, A1298C, and G1793A). We observed significantly higher Hcy levels in patients as compared to controls. The frequency of MTHFR 1298CC genotype was significantly higher in ESRD patients than in controls (21.4% vs. 2.9%); the frequency of the MTHFR C677T genotypes did not differ between groups (26.1% vs. 17.4%). Compound heterozygous MTHFR 677CT/1298AC genotypes showed maximum association with the risk of ESRD (OR: 12.8; 5%CI: 1.64-10.01, P < 0.05). Concurrent occurrence of MTHFR 677CC wild genotype with either 1298CC or 1793GA significantly increased the risk of disease (OR: 7.20; 95%CI: 2.06-2.51, P < 0.001 and OR: 7.60; 95%CI: 1.68-34.35; P < 0.05, respectively). MTHFR 1298CC genotype was associated with higher Hcy levels. IMT was also significantly higher in patients with the 1298CC genotype (P < 0.05). Thus, A1298C polymorphism of MTHFR gene appears to be associated with the severity of carotid atherosclerosis and co-occurrence of MTHFR polymorphisms may be a risk factor for CVD in patients on hemodialysis.
Mol Cell Biochem 2008 Jan
PMID:MTHFR A1298C polymorphism is associated with cardiovascular risk in end stage renal disease in North Indians. 1789 17

Hyperhomocysteinemia has been documented in chronic renal failure (CRF). Premature as well as progressive occlusive vascular disease is common. Mutations or polymorphisms in the gene of the enzyme methylenetetrahydrofolate reductase (MTHFR), as C677T, A1298C and G1793A, are associated with hyperhomocysteinemia and possibly with elevated risk for vascular diseases. This study was conducted on 89 individuals with renal failure on dialysis to determine the allelic and genotypic frequencies of the mutations in the MTHFR gene and hyperhomocysteinemia. Blood samples were colleted for determination of homocysteine and DNA. The C677T, A1298C and G1793A mutations were detected. This study confirmed the high prevalence of hyperhomocysteinemia in patients on dialysis, which was diagnosed in 76 patients (85.39%) and high incidence of the C677T and A1298C mutation, 42 (47.19%) and 29 (32.58%) patients, respectively. Five patients (5.62%) presented the G1793A mutation and hyperhomocysteinemia. The authors concluded that there was no influence of the polymorphisms on homocysteine levels in these patients.
Mol Nutr Food Res 2007 Nov
PMID:Hyperhomocysteinemia and polymorphisms of the methylenetetrahydrofolate gene in hemodialysis and peritoneal dialysis patients. 1796 40


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