Background information
Bardet-Biedl syndrome (BBS) is a pleiotropic genetic disorder characterized by obesity, photoreceptor degeneration, polydactyly, hypogenitalism, renal abnormalities, and developmental delay. Other associated clinical findings in BBS patients include diabetes, hypertension, and congenital heart defects. BBS is a heterogeneous disorder that maps to eight genetic loci and encodes eight proteins, BBS1-BBS8. Five BBS genes encode basal body or cilia proteins, suggesting that BBS is a ciliary dysfunction disorder. BBS2 is a 721-amino acid protein that is evolutionarily conserved and is expressed in a broad range of tissues including: brain, kidney, adrenal gland, and thyroid gland. Loss of BBS2 may be involved in defects in social interactions as well as infertility. BBS2 retinopathy involves normal retina development followed by apoptotic death of photoreceptors, the primary ciliated cells of the retina.
