Furthermore, severe obesity was found in congenitally leptin-deficient humans of Pakistani origin caused by a homozygous frameshift mutation consisting of a single guanine deletion in codon 133 (Δ133G or g.13374delG) of the LEP gene, affecting the protein p.Gly133Valfs*15. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.