CLRN1 (c.459 del3 (delATT), p.N48K, p.L150P), USH3, characterized by progressive post-lingual hearing loss, sensorineural, variable vestibular dysfunction, as well as retinitis pigmentosa. Some of the symptoms of retinitis pigmentosa include nyctalopia, progressive restriction of visual fields, and reduction of central visual acuity in these individuals. USH3 is inherited in an autosomal recessive manner, and has an increased frequency in Finland accounting for 40% of all Usher Syndrome patients in Finland. The CLRN1 gene encodes the small transmembrane glycoprotein, clarin-1, which is expressed in the retina, skeletal muscles, olfactory epithelium, hair cells of the Corti, and in spiral ganglion cells. This gene is mutated causing the vision and hearing loss in USH3 individuals.