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)

Methlenetetrahydrofolate (CH2-H4folate) is required for the conversion of homocysteine to methionine and of dUMP to dTMP in support of DNA synthesis, and also serves as a major source of one carbon unit for purine biosynthesis. This review presents biochemical studies of a human polymorphism in methylenetetrahydrofolate reductase, which catalyzes the reaction shown below. The mutation decreases the flux of CH2-H4folate into CH3-H4folate, and is associated with both beneficial and deleterious effects that can be traced to the molecular effect of the substitution of alanine 222 by valine.
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PMID:Methylenetetrahydrofolate reductase: a common human polymorphism and its biochemical implications. 1193 57

Mild hyperhomocysteinemia is one of the known strong risk factors for atherosclerotic diseases, and therefore it is important to clarify factors that could determine plasma total homocysteine (tHcy) level. A cross-sectional study with a random sample of 455 Japanese rural residents aged 40-69 years was conducted in 2000 to investigate the associations of plasma tHcy concentration with 5,10-methylenetetrahydrofolate reductase (MTHFR) gene and selected life-style related factors. The frequency of the mutant allele, Valine (V) allele, was 0.40 and the prevalence of VV genotype was 14.3%. Plasma tHcy concentration in VV was significantly higher than those in two other genotypes. There were significant inverse associations of plasma tHcy with serum folate and serum vitamin B12 (P<0.001 for trend, respectively); both being stronger in VV than in other genotypes. The number of cigarettes smoked per day was positively associated with plasma tHcy concentration. A multivariate regression analysis revealed that serum folate, serum vitamin B12, and MTHFR genotype were independently associated with plasma tHcy. The inter-individual variance of plasma tHcy was more explained by serum folate and vitamin B12 than by MTHFR genotype. Higher intakes of folate, vitamin B12, and non-smoking may be important to prevent mild hyperhomocysteinemia and the eventual atherosclerotic diseases in this Japanese rural population.
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PMID:Are the associations between life-style related factors and plasma total homocysteine concentration different according to polymorphism of 5,10-methylenetetrahydrofolate reductase gene (C677T MTHFR)? A cross-sectional study in a Japanese rural population. 1203 23

High plasma homocysteine, a risk factor for atherosclerosis, is frequently caused by a common mutation in the gene for the enzyme, 5,10-methylenetetrahydrofolate reductase (MTHFR), C677T (alanine to valine substitution) or low intake of B vitamins that affect the remethylation or transsulfuration pathways in homocysteine metabolism. However, the interaction of the C677T mutation and B vitamins other than folate has not been well elucidated. We conducted a cross-sectional survey of 324 men and 641 women who participated in a 1996 health examination under a hypothesis that high nutritional status of folate, vitamin B12 and vitamin B6 expressed as high serum levels, may compensate for the hyperhomocysteinemia associated with homozygosity for the C677T mutation, but not for having the mutation per se. Age-adjusted plasma homocysteine levels were higher for both men and women with the homozygous genotype for the mutation than those who were heterozygous or had no mutation. Elevated homocysteine levels in homozygous genotype was attenuated among persons with higher serum levels of vitamin B12 and folate, but not vitamin B6, and among persons with the combination of lower folate and higher vitamin B12 and of higher folate and higher vitamin B12, split by the median. These findings suggest that elevated homocysteine levels among Japanese with the homozygous genotype for the MTHFR gene mutation can be modified efficiently by dietary supplement of vitamin B12 as well as folate.
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PMID:Effects of serum B vitamins on elevated plasma homocysteine levels associated with the mutation of methylenetetrahydrofolate reductase gene in Japanese. 1220 4

The patient had suffered from left hemiparesis at the age of thirteen months, and acute ischemic stroke of unknown etiology had been diagnosed at that time. His hemiparesis gradually disappeared and he was discharged two weeks after the onset without disability. At the age of 17 years, MRI following minor head trauma revealed cerebral infarctions located at the right corona radiata and basal ganglia. Laboratory findings showed hyperhomocysteinemia. Genetic study disclosed methylenetetrahydrofolate reductase deficiency (MTHFRD) (valine/valine type). MTHFRD is not detected by the routine infantile mass screening test for congenital amino acid metabolic disease, and should be considered in any patient with ischemic stroke at under two years of age.
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PMID:[Case of juvenile stroke caused by methylenetetrahydrofolate reductase deficiency]. 1861 55

A functional polymorphism in methylenetetrahydrofolate reductase (MTHFR) has been identified at codon 677 (C677T). The T-allele variant (valine type) has lower enzyme activity than the wild type (C-allele or alanine type), resulting in a slightly elevated homocysteine level, which has been recently recognized as a risk factor for fracture. However, whether subjects bearing the T allele have higher susceptibility to fractures is still controversial. We have investigated the effects of MTHFR polymorphism on fracture susceptibility in Japanese postmenopausal women. A total of 502 postmenopausal ambulatory Japanese women were followed up for 5.1 +/- 3.4 (mean +/- SD) years, and a total of 155 patients with incident fractures (121 patients with vertebral fractures and 34 cases with fractures at other sites) were recorded. When compared with the patients without any fractures, the patients with incident fractures were older, had more prevalent fractures, had higher urinary levels of bone turnover markers as well as plasma homocysteine level, but were shorter in body height and had lower bone mineral density. The prevalence of the TT genotype of MTHFR was significantly higher in the patients with incident fractures compared to the other genotypes. The subjects with the TT genotype had a higher incidence rate of fracture and higher plasma level of homocysteine than the subjects bearing the non-TT genotype. This relationship was observed in both osteoporotic and nonosteoporotic groups. The hazard ratio for TT genotype without osteoporosis, non-TT genotype with osteoporosis, and TT genotype with osteoporosis was 1.49 (0.91-2.45), 3.64 (2.50-5.29), and 7.21 (4.34-11.97), respectively, compared to the non-TT genotype without osteoporosis. A higher hazard ratio for the TT genotype with osteoporosis was still apparent after adjustment for age, body size, and number of prevalent vertebral fractures. These results indicate that the TT genotype of MTHFR may be a risk factor for future fracture in addition to the traditional risk factors.
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PMID:The synergistic effect of bone mineral density and methylenetetrahydrofolate reductase (MTHFR) polymorphism (C677T) on fractures. 1897 59

Prostate cancer is the most common malignancy and the second leading cause of cancer related deaths among men in many countries. Serum levels of prostate-spesific antigen (PSA) have attracted attention for prediction purposes. The methylenetetrahydrofolate reductase (MTHFR) gene play a critical role in cancer development, but its potential impact on prostate cancer has not been well studied. The C677T variant lies in exon 4 at the folate binding site of the MTHFR gene and results in substitution of an alanine by a valine residue. The present study was carried out 55 cases with prostate cancer and 50 healthy men. Polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), and agarose gel electrophoresis techniques were employed to determine MTHFR C677T mutation. The frequencies of the CT genotype (p= 0.025) and T allele (p= 0.023) was found to be higher in control subjects when compared with patients group. No statistical difference was found between the alleles of MTHFR and PSA levels after (PSA-BT)/ before (PSA-AT) antiandrogen treatment or tumor stages. We suggest that the heterozygote CT genotype and the 677T allele of the MTHFR polymorphism might be associated with an decreased prostate cancer risk.
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PMID:Effects of the MTHFR C677T polymorphism on prostate specific antigen and prostate cancer. 2229 69

There have been many controversial debates on the role of Hyperhomocysteinaemia (HHcy) as an independent risk factor for Coronary Artery Disease (CAD) during recent years. Furthermore, an alanine/valine (Ala/Val) gene polymorphism at 222nd amino acid of 5,10-methylenetetrahydrofolate reductase (MTHFR) has been considered as a factor that could render this enzyme thermolabile and less active which in turn may yield a subsequent increase in plasma total homocysteine (tHcy) levels. To assess whether this polymorphism is associated with increased risk of CAD and plasma levels of tHcy in a population from southern Iran, a total of 457 patients with angiographically documented multi-vessel CAD were compared with a control group comprised of 371 subjects with <30% stenosis in all major vessels. Nevertheless our results failed to admit a significant difference between CAD individuals and control subjects for Ala/Val polymorphism and plasma Hcy concentrations. However, plasma Hcy concentrations were significantly higher in individuals with Val/Val genotype than subjects with Ala/Ala genotype, but it didn't show a significant association with CAD in our population. Moreover, as the multiple linear regression analysis indicated, smoking habit, folate levels and the MTHFR Val/Val genotype were the only major predictors of tHcy concentrations in the current investigation.
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PMID:An MTHFR variant, plasma homocysteine levels and late-onset coronary artery disease in subjects from southern Iran. 2449 31


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