KCNQ1 and obesity due to melanocortin 4 receptor deficiency: Differential methylation was found in genes associated with obesity, epigenetic regulation and development, such as cholesteryl ester transfer protein (CETP), forkhead box P2 (FOXP2), HDAC4, DNMT3B, potassium voltage-gated channel subfamily Q member 1 (KCNQ1) and homeobox (HOX) clusters.