The relationship between Usher's syndrome and psychosis with Capgras syndrome.

Usher's syndrome is a genetic disorder that causes congenital sensorineural hearing loss, visual impairment due to progressive pigmentary retinopathy, and, often, vestibular dysfunction. The aim of this article is to illustrate a case that clearly demonstrates psychotic symptoms in Usher's syndrome Type III and serves to increase clinical awareness of this disorder and its possible link to psychotic symptoms. There is some evidence in the literature of concurrent psychiatric symptoms, particularly psychotic symptoms, associated with Usher's syndrome, and several theories around this association have been proposed. These theories of associations include a genetic link between the genes responsible for schizophrenia and the genes for Usher's syndrome; a neuropathological explanation as radiologic studies have revealed that patients with Usher's syndrome have CNS abnormalities in multiple brain structures; and a sensory deficit model which proposes that the stressors associated with sensory impairment and the brain's adaptation to changes in sensory inputs place an individual at increased risk for psychopathology.