Previous studies have reported an association between GDM and HIF3A methylation [22], though this was in the area covered by HIF3A. 1. While we have found novel evidence for GDM influencing average methylation in HIF3A. 2, no such association was observed for HIF3A. 1. However, there were relatively few women in our population-derived cohort with GDM (n = 17 for the HIF3A. 1 sub-cohort) compared to the previous study that was enriched for mothers with GDM (n = 68) [22]. The gene discussed is HIF3A; the disease is gestational diabetes.