Samples (n = 119) from a previous randomised controlled trial in pregnancy were used to compare the DNA methylation profiles of the same woman pre- versus post-folic acid intervention. Candidate genes were identified from the literature and a pilot genome wide screen of six women (three from each of the folic acid and placebo arms of the trial). We did not observe consistent DNA methylation changes in response to folic acid intervention at any of our candidate genes (RASA4, DHFR, DHFR2, RASSF1A, EIF2C3, ATPF1). We did identify a 40% decrease in DNA methylation at the RASA4 promoter correlating with a 3.5-fold increase in its mRNA abundance in an in vitro cell culture model.
Continued folic acid intervention over a 22-week period did not appear to significantly influence the DNA methylation status of six candidate genes in blood samples of women compared to placebo. However, DNA methylation may play a role in the gene expression control of the RASA4 gene.