Usher syndrome
Usher syndrome is a relatively rare genetic disorder caused by a mutation in any one of 10 genes resulting in a combination of hearing loss and visual impairment, and is a leading cause of deafblindness. Usher syndrome is incurable at present.Other names for Usher syndrome include Hallgren syndrome, Usher-Hallgren syndrome, retinitis pigmentosa-dysacusis syndrome, and dystrophia retinae dysacusis syndrome.