FTO and obesity due to melanocortin 4 receptor deficiency: In adults, the strongest associations with the risk of obesity were discovered for single-nucleotide polymorphisms (SNPs) in the FTO, MC4R, TMEM18, TNNI3K, SEC16B, GNPDA2, POMC, RPGRIP1L, IRX3, and IRX5 genes [8,9,10,11].