Effects of the interaction between the C677T 5,10-methylenetetrahydrofolate reductase polymorphism and serum B vitamins on homocysteine levels in pregnant women

Abstract

Objective: The purpose of this study was to investigate the effect of the interaction between the C677T mutation in the 5,10-methylenetetrahydrofolate reductase (MTHFR) genotypes and serum levels of B vitamins on serum homocysteine levels in pregnant women. Design: A cross-sectional study. Setting: Ewha Womans University Hospital, Seoul, Korea. Subjects: A total of 177 normal pregnant women, 24.671.1 weeks of gestation, in a 6-month period during [2001][2002]. Interventions: Serum vitamin B 2 , vitamin B 6 , and homocysteine analyses were conducted using high-performance liquid chromatography methods. Serum folate and vitamin B 12 concentrations were determined using a radioimmunoassay kit. MTHFR gene mutation was investigated by the polymerase chain reaction of a genomic DNA fragment. Results: Serum homocysteine was higher in women with the T/T genotype than those with the C/T or C/C genotype of the MTHFR gene (Po0.05). Serum homocysteine was negatively correlated with serum folate in all MTHFR genotypes (Po0.001), and the correlation between the two serum levels was the strongest in the T/T genotype. Serum homocysteine was higher in the subjects with the T/T MTHFR genotype only when the serum folate was below the median level. Explanatory power of B vitamin status as predictors of serum homocysteine levels was more pronounced in the T/T genotypes (68.5%) compared with the C/T (37.9%) or C/C genotypes (20.6%). Conclusions: Serum homocysteine levels in pregnant women varied significantly with MTHFR genotype and the serum B vitamin status. Higher serum folate, vitamin B 2 , and vitamin B 12 concentrations may lessen the MTHFR genotypic effect on serum homocysteine levels.

The effects of homocysteine and MTHFR genotype on hip bone loss and fracture risk in elderly women

“…Another limitation of the study is that we did not evaluate the association between homocysteine levels and Results are the mean±SD or mean±SEM for differences or n (%) as stated a The CC genotype had significantly higher rate of prevalent fracture than the AA and AC genotypes, P=0.024 (chi-square test) b Analysis adjusted for baseline age and weight, 1 year hip BMD, prevalent fracture, calcium treatment, and compliance with study tablets some medications, such as anti-epileptic, lipid-lowering, and antihypertensive drugs, that have been reported to influence homocysteine levels [40,41]. Consistent with previous analyses [15,42,43], an increased plasma homocysteine level was observed in those with the MTHFR C677T TT genotype and either low folate intake or low riboflavin intake. These data support that this polymorphism impairs the MTHFR enzyme activity and thus the conversion of homocysteine to methionine, especially in the presence of suboptimal levels of dietary folate and riboflavin, which are both necessary for the conversion.…”

Association of maternal folate nutrition and serum C-reactive protein concentrations with gestational age at delivery

“…Several groups of investigators, including our own, have reported an inverse association between homocysteine and folate concentration in pregnant women (Guerra-Shinohara et al, 2002;Kim et al, 2004;Park et al, 2004;Lindblad et al, 2005). Elevated plasma homocysteine during pregnancy has been implicated in placental vascular changes in preeclampsia (de Vries et al, 1997).…”

The association between mother and child MTHFR C677T polymorphisms, dietary folate intake and childhood atopy in a population‐based, longitudinal birth cohort

“…When mothers' allergic status was restricted to asthma, the prevalence was closer to the observed prevalence of atopy in the children and there remained no evidence of an association with the MTHFR genotype. We did not have objective measurements of maternal folate status based on blood samples in this study but there is good evidence that MTHFR C677T is a functional polymorphism that is linked to plasma homocysteine levels and modified by dietary folate status [31]. Although, a deficiency state associated with TT homozygosity might influence dietary behaviour, there was no evidence from our analyses that maternal folate intake varied by the MTHFR C677T genotype.…”