Recently, genome-wide association studies (GWAS), performed mostly among Caucasians, identified that the alleles of RAS p21 protein activator 2 (RASA2), cell adhesion molecule 1 (CADM1) and hypoxia inducible factor 1 alpha subunit inhibitor (HIF1AN) genes were tightly associated with obesity in the general population [15]. This evidence concerns the gene HIF1AN and obesity due to melanocortin 4 receptor deficiency.