We examined whether polymorphisms in the methylenetetrahydrofolate dehydrogenase (MTHFD) and transcobalamin (TC) genes, which are involved in folate metabolism, affect maternal risk for Down syndrome. We investigated 76 Down syndrome mothers and 115 control mothers from Bengbu, China. Genomic DNA was isolated from the peripheral lymphocytes. Polymerase chain reaction and restriction fragment length polymorphism were used to examine the polymorphisms of MTHFD G1958A and TC C776G.
We conducted a hospital-based case-control study to investigate the associations of dietary intake of folate and MTHFR C677T and A1298C polymorphisms with breast cancer in a Chinese population. A 1:1-matched case-control study was conducted. Two hundred and thirty patients who were newly diagnosed and histologically confirmed breast cancer and 230 controls were enrolled from Xinxiang Central Hospital. Folate intake was calculated by standard portion size and relative size for each food item in the questionnaire. Genotyping of MTHFR C677T and A1298C was performed by PCR-RFLP.
We investigated the association between dietary intake of folate, vitamin B6, and the 5,10-methylenetetrahydrofolate reductase (MTHFR) genotype with breast cancer. A matched case-control study was conducted, and 413 patients with newly diagnosed and histologically confirmed breast cancer and 436 controls were recruited. Folate intake, vitamin B6, and vitamin B12 levels were calculated, and the MTHFR C677T and A1298C and MTR A2756G polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism.
Hypomethylation of the O6-methylguanine-DNA-methyltransferase (MGMT) promoter in glioma cells has been associated with temozolomide resistance. S-adenosylmethionine (SAM), which is produced during folate metabolism, is the main source of methyl groups during DNA methylation. As a key enzyme during folate metabolism, polymorphisms of 5,10-methylenetetrahydrofolate reductase (MTHFR) may regulate folate end-products.
Association between neural tube defects (NTDs) and C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene was suspected, because the MTHFR gene codes for a key enzyme in folate metabolism. Its deficiency usually leads to significant reductions in plasma concentrations of folate, vitamin B12 and methionine, whereas homocysteine levels are increased. We examined folate, vitamin B12 and homocysteine serum concentrations and polymorphism of the C677T MTHFR gene in Turkish children with neural tube defects.