LEP and obesity due to melanocortin 4 receptor deficiency: Previous studies examining the genetic causes of severe early-onset obesity in Pakistani families have mainly focused on a few genes most often linked to monogenic forms of obesity i.e. LEP, LEPR and MC4R [10, 12, 55–57], yet, more recently, a mutation screen of multiple genes was performed in 39 unrelated children with severe obesity from consanguineous Pakistani families [56].