Evaluating Methylation of the Oxytocin Receptor Gene and the Oxytocin Intergenic Region.

Oxytocin and its paralogue, vasopressin, are widely studied biomarkers in relation to pregnancy and birth, maternal and social behavior, and mental health. Epigenetics is a biological mechanism that mediates the link between environmental influences and behavioral patterns. In a candidate gene approach, we describe here a DNA methylation assay of two regions within the oxytocin system, using human buccal cells and next-generation sequencing. Two nanograms of DNA were sufficient to assess the DNA methylation status of 28 CpG sites (22 corresponding to the oxytocin receptor and 6 corresponding to the vasopressin/oxytocin intergenic region). This method proved to be non-invasive for the participants, and reproducible; its validity remains to be confirmed alongside other biomarkers of gene function.