Evidence for several genome-wide association studies (GWAS) has indicated that several common single nucleotide polymorphism (SNP) variants, such as rs1421085 and rs9930506, located in the first intron of fat mass and obesity associated (FTO) gene, are strongly associated with an increased risk of obesity (6–8), and the functional loci and biological targets associated with these variants are largely unknown. The gene discussed is FTO; the disease is obesity due to melanocortin 4 receptor deficiency.