Usher syndrome (USH) is an autosomal recessively inherited disease characterized by sensorineural hearing loss (SNHL) and retinitis pigmentosa (RP) with or without vestibular dysfunction. It is highly heterogeneous both clinically and genetically. Recently, variants in the arylsulfatase G ( ARSG ) gene have been reported to underlie USH type IV. This distinct type of USH is characterized by late-onset RP with predominantly per...