FTO and obesity due to melanocortin 4 receptor deficiency: Fat mass and obesity-associated protein (FTO), melanocortin 4 receptor (MC4R), and brain-derived neurotrophic factor (BDNF) genetic variants have been reported to be strongly associated with obesity risk in a genome-wide association study (GWAS) and meta-analysis studies of children and adults of different ethnicities including Europeans, Americans, Asians, and Africans [8,9,10,11,12].