BBS is a condition characterised by progressive retinal dystrophy, obesity, polydactyly and renal anomalies. There are considerable phenotypic heterogeneity and not all BBS patients are affected similarly.

BBS is a childhood condition that affects many organs in the body. The main features are retinitis pigmentosa, polydactyly, obesity and kidney abnormalities. Other less common features have been reported as well, and not all patients are affected similarly.