Consistent with this hypothesis, individuals with similar missense changes presented with a milder phenotype characterized by retinopathy and variable polydactyly with or without obesity or multiorgan anomalies [4], suggesting that a narrow spectrum of BBS9 changes, restricted to the β-propeller domain, may cause a milder phenotype of BBS9. The gene discussed is BBS9; the disease is obesity due to melanocortin 4 receptor deficiency.