MC4R and obesity due to melanocortin 4 receptor deficiency: Pathogenesis of obesity involves a combination of excessive caloric intake, sedentary lifestyle, and the effects of multiple hormones and adipokines that involve body weight and appetite control such as leptin, adiponectin, proopiomelanocortin, prohormone convertase 1, melanocortin receptor 3 (MC3R), and melanocortin receptor 4 (MC4R) [2].