MTNR1B and diabetes mellitus: Among the genes involved in the etiology of obesity and diabetes can be named Melanocortin 4 receptor (MC4R), Melatonin Receptor 1B (MTNR1B), Peroxisome proliferator-activated receptor gamma (PPAR-γ), Phosphatase and tensin homolog (PTEN), Acetyl-CoA Carboxylase Beta (ACACB), and peroxisome proliferator-activated receptor-α (PPAR-α), MC4R gene encodes melanocortin receptor, MC4 protein, a G-protein receptor that high it’s expression is related to body fat distribution and energy intake in children [16].