Adverse physiological conditions during pregnancy such as maternal obesity and gestational diabetes have been associated with higher placental LEP methylation (Lesseur et al. 2014b), whereas other studies have found lower placental LEP methylation in mothers with early-onset preeclampsia (Hogg et al. 2013) or impaired glucose metabolism (Bouchard et al. 2010). The gene discussed is LEP; the disease is gestational diabetes.