The MTHFR 677TT genotype and folate intake interact to lower global leukocyte DNA methylation in young Mexican American women

• Published in: Nutrition research (New York, N.Y.) N.Y.), 2007-01, Vol.27 (1), p.1365-1317
• Main Authors: Axume, Juan, Smith, Steven S, Pogribny, Igor P, Moriarty, David J, Caudill, Marie A
• Format: Article
• Language: English
• ISSN: 0271-5317; 1879-0739
• DOI: 10.1016/j.nutres.2006.12.006

DNA methylation is an epigenetic feature that is associated with X chromosome inactivation, genomic imprinting, transcriptional silencing of genes and genomic stability. Folate provides a labile source of methyl groups which may be used for cellular methylation reactions including DNA methylation. The methylenetetrahydrofolate reductase (MTHFR) 677C-->T variant is an important determinant of folate nutriture and may influence DNA methylation. This study sought to assess the influence of the MTHFR C677T genotype on global leukocyte DNA methylation in young (18-45y) Mexican American women (n=43; 14 CC, 12 CT and 17 TT). Subjects consumed a folate restricted diet (135 mug DFE/d) for 7 wk followed by folate treatment with 400 or 800 mug DFE/d for 7 wk. Global leukocyte DNA methylation was assessed via the cytosine extension assay at week 0, week 7 (after folate restriction) and week 14 (after folate treatment). No main effects of MTHFR C677T genotype or folate intake were detected at any time point during the study. However, at the end of folate treatment (wk 14), DNA methylation was lower (P