Some of the common genes that contribute towards obesity and subsequently leptin resistance are: mutations in leptin (LEP), leptin receptor (LEPR), Melanocortin 4 receptor (MC4R), Proopiomelanocortin (POMC), Brain-derived neurotrophic factor (BDNF), Proprotein convertase subtilisin/kexin type 1 (PCSK1), and peroxisome proliferator-activated receptor (PPARs) [213,214,215,216,217,218,219]. The gene discussed is PCSK1; the disease is obesity due to melanocortin 4 receptor deficiency.