Defects in HARS are a cause of Usher syndrome type 3B (USH3B). USH3B is a syndrome characterized by progressive vision and hearing loss during early childhood. Some patients have the so-called 'Charles Bonnet syndrome,' involving decreased visual acuity and vivid visual hallucinations. USH is a genetically heterogeneous condition characterized by the association of retinitis pigmentosa with sensorineural deafness. Age at onset and differences in auditory and vestibular function distinguish Usher syndrome type 1 (USH1), Usher syndrome type 2 (USH2) and Usher syndrome type 3 (USH3). USH3 is characterized by postlingual, progressive hearing loss, variable vestibular dysfunction, and onset of retinitis pigmentosa symptoms, including nyctalopia, constriction of the visual fields, and loss of central visual acuity, usually by the second decade of life. Belongs to the class-II aminoacyl-tRNA synthetase family.Raben N., Nucleic Acids Res. 20:1075-1081(1992).Tsui F.W.L., Nucleic Acids Res. 15:3349-3367(1987).Tsui H.W., Gene 131:201-208(1993).