Bardet-Biedl Syndrome (BBS)
Bardet-Biedl syndrome is a complex disorder that affects many parts of the body including the retina. Individuals with BBS have a retinal degeneration similar to retinitis pigmentosa (RP).
The diagnosis of Bardet-Biedl syndrome (BBS) is usually confirmed in childhood when (usually) RP-like visual problems are discovered. The first symptom is night blindness, making it difficult to see in low light levels. Then, there may be progressive loss of peripheral (side) vision. Visual symptoms progress rapidly and usually lead to severe visual impairment by early adulthood. In addition to vision problems, other defining characteristics of BBS may be polydactyly (extra fingers and/or toes), obesity and kidney (renal) disease. Renal abnormalities can affect the structure and the function of the kidneys and can lead to severe renal impairment. Recently, scientists have discovered that some BBS genes code for proteins that support cilia, fingerlike projections found on many cells, including photoreceptors and renal cells. This may explain why one individual may have both vision and kidney problems. For more information, see Cilia