Compared with children without obesity, children with obesity had 251 promoters and 575 CGIs demethylated, and 141 promoters and 277,251 promoters hypermethylated. Four genes (FZD7, PRLHR, EXOSC4, and EIF6) with differential promoter methylation were validated. The gene discussed is PRLHR; the disease is obesity due to melanocortin 4 receptor deficiency.