A common variant in methylenetetrahydrofolate reductase (MTHFR677C→T) causes mild MTHFR deficiency with lower 5-methyltetrahydrofolate for methylation reactions.
Testicular MTHFR protein levels decreased significantly in wild-type mice on the 20× diet but not in those on the 10× diet, suggesting a possible role for MTHFR deficiency in sperm DNA hypomethylation.
The diagnosis of MTHFR deficiency was confirmed based on extremely reduced fibroblast MTHFR activity (0.3 nmol CHO/mg prot/hr) as well as mutation analysis that revealed two variants in the MTHFR gene, a splice site mutation p (IVS5-1G>A), as well as a missense mutation (c.155 G>A; p. Arg52Gln).
In the latter group, remethylation disorders of homocysteine to methionine (chiefly CblC defect and 5,10-methylenetetrahydrofolate reductase [MTHFR] deficiency) are by far the most frequently encountered situations.
Five patients suspected of having non-classical homocystinuria due to MTHFR deficiency were examined with respect to their symptoms, MTHFR enzyme activity and genotypes of the MTHFR gene.
Life-threatening methylenetetrahydrofolate reductase (MTHFR) deficiency with extremely early onset: characterization of two novel mutations in compound heterozygous patients.
These results underscore the importance of folate interconversion in VPA-induced teratogenicity, since VPA increases MTHFR expression and has lower teratogenic potential in MTHFR deficiency.
To investigate the in vivo pathogenetic mechanisms of MTHFR deficiency, we generated mice with a knockout of MTHFR: Plasma total homocysteine levels in heterozygous and homozygous knockout mice are 1.6- and 10-fold higher than those in wild-type littermates, respectively.
In earlier work, we isolated the human cDNA for MTHFR, and reported 14 mutations in severe MTHFR deficiency, as well as a common 677C-->T missense mutation (Ala-->Val) that encodes the thermolabile MTHFR.
The ongoing identification and characterisation of mutations in the MTHFR gene will provide further insight into the heterogeneity of the clinical phenotype in severe MTHFR deficiency.
Seven novel mutations in the methylenetetrahydrofolate reductase gene and genotype/phenotype correlations in severe methylenetetrahydrofolate reductase deficiency.
The biochemical features in these four subjects are distinguishable from subjects homozygous for the thermolabile MTHFR, whose specific activity is approximately 50% of the normal mean, and from heterozygotes for severe MTHFR deficiency, in whom the enzyme is thermostable and has a specific activity of about 50% of the normal mean.
The combination of MTHFR deficiency and HFAT exacerbates changes in inflammatory mediators and introduces additional effects on inflammation (Saa2) and lipid metabolism (Nr1h4, Srebf1c, Ppara, and Crot).
The combination of MTHFR deficiency and HFAT exacerbates changes in inflammatory mediators and introduces additional effects on inflammation (Saa2) and lipid metabolism (Nr1h4, Srebf1c, Ppara, and Crot).