TMEM18 and obesity due to melanocortin 4 receptor deficiency: From the Genetic Investigation of Anthropometric Traits (GIANT) consortium, additional loci were associated with obesity, like transmembrane protein 18 (TMEM18), potassium channel tetramerization domain containing 15 (KCTD15), glucosamine-6-phosphate deaminase 2 (GNPDA2), Src homology 2B (SH2B) family member 1 (SH2B1), mitochondrial carrier 2 (MTCH2), the melanocortin 4 receptor (MC4R), and the neuronal growth regulator 1 (NEGR1) genes [14].