BEST1

Mutations in the BEST1 gene can cause retinal degenerative disorders called bestrophinopathies. These mutations can cause eye abnormalities similar to retinitis pigmentosa, but it's not clear if BEST1 gene mutations are a major cause of retinitis pigmentosa. The BEST1 gene provides instructions for making the protein bestrophin-1, which is found in the retinal pigment epithelium (RPE) cells of the eye. Bestrophin-1 helps regulate calcium signaling and allows chloride ions to flow in and out of RPE cells. Retinitis pigmentosa is a group of eye disorders that cause vision loss by gradually deteriorating the photoreceptors in the retina. Symptoms include reduced vision in low light, difficulty seeing objects in the periphery, and a gradual narrowing of the area of good vision. The most common inheritance pattern for retinitis pigmentosa is autosomal recessive (definition: An inheritance pattern where a person needs an altered copy of a gene from both parents to be affected. Parents with only one copy are usually unaffected carriers.), which affects about 20% of cases. Autosomal dominant (definition: An inheritance pattern where a single altered copy of a gene, from just one parent, is enough to cause the condition.) inheritance affects 10–20% of cases, and X-linked (definition: An inheritance pattern where the altered gene is on the X chromosome. These conditions often affect males more severely, though some female carriers have symptoms too.) recessive inheritance affects 10%. At present, there's no cure for retinitis pigmentosa, but some treatments can slow vision loss or restore some sight.