The BBS9 (Bardet-Biedl syndrome 9) gene located within SCR4 constitutes one of the 15 loci that are associated with Bardet-Biedl syndrome (BBS), which in humans is a genetically heterogeneous disorder characterized by marked obesity among other clinical features [28]. The gene discussed is BBS9; the disease is obesity due to melanocortin 4 receptor deficiency.