PMC

Proteins involved in the uptake, retention, and metabolism of folate. FOLH1, folate hydrolase 1 (γ carboxy peptidase II); FOLR1, folate receptor 1; FPGS, folate polyglutamate synthase; GGH, γ-glutamyl hydrolase; MTHFR, methylene tetrahydrofolate reductase; MTR, methionine synthase; PCFT (SLC46A1), proton-coupled folate transporter; RFC1 (SLC19A1), reduced folate carrier 1; 1-C, one-carbon.

Association of the γ-glutamyl hydrolase (GGH) single nucleotide polymorphisms rs11545076 genotype with blood DNA uracil concentrations. Values are expressed as means ±SEMs. n = 128, 92, and 18 for the TT, TG, and GG genotypes, respectively. Uracil data were adjusted for age, sex, plasma folate, vitamin B-12, and plasma pyridoxal phosphate. *P for trend (additive model) = 0.022 and 0.058 for the untransformed and log-transformed models, respectively.

Association of single nucleotide polymorphisms (SNPs) in methylene tetrahydrofolate reductase (MTHFR), reduced folate carrier 1 (RFC1), and folate hydrolase 1 (FOLH1) with plasma folate and homocysteine (Hcy) concentrations. Values are expressed as adjusted means ± SEMs. Hcy values were adjusted for age, sex, alcohol intake, plasma folate, plasma pyridoxal phosphate, vitamin B-12, and creatinine. Folate data were adjusted for age, sex, smoking status, alcohol intake, and dietary folate equivalent intake. *Log homocysteine and folate significantly different (P ≤ 0.05, general linear model) from other 2 genotypes combined (dominant/recessive) after adjustment for the abovementioned factors (n = 875–929). Note that for the FOLH1 1561C>T SNP (C), the CT and TT genotypes were combined because n = 2 for the TT genotype.