DRD2 and obesity due to melanocortin 4 receptor deficiency: Dopaminergic genes, including DRD2, ANKK1, OPRM1, COMT, DAT1 and DRD3, especially a polymorphism called Taq1A of DRD2, have been associated with higher reward sensitivity and obesity [28,29,30], which is of significant interest in the effective treatment of BED.