Among the six leptin-associated loci, three genes (MC4R, BDNF, and PCSK1) are known to be involved in the hypothalamic leptin–melanocortin pathway [9, 17, 30], thus it is not surprising that those three loci are found to be associated with obesity-related traits and leptin levels in our pediatric setting. The gene discussed is PCSK1; the disease is obesity due to melanocortin 4 receptor deficiency.