LEP and obesity due to melanocortin 4 receptor deficiency: Two single-nucleotide variants (SNVs) in the leptin gene, G19A and G2548A, located in the 5′ untranslated region (UTR) of the human leptin gene, have been reported to be associated with body mass index (BMI) and obesity, as well as leptin levels, but with discordant results [12,13,14,15,16,17,18,19,20].