DRD2 and obesity due to melanocortin 4 receptor deficiency: The aims of this study were to assess the frequency of obesity, hypertension, metabolic syndrome, insulin resistance, and dyslipidemia in a sample of child and adolescent users of risperidone, to evaluate associations with clinical and pharmacological data and with certain polymorphisms of the HTR2C, DRD2, LEP, LEPR, MC4R, and CYP2D6 genes.