Usher syndrome is a rare autosomal-recessive disorder manifested primarily by sensorineural hearing loss and retinitis pigmentosa. Although others described the syndrome earlier, it is named for Charles Usher, a British ophthalmologist who emphasized the role of heredity in the disorder. The degree of hearing loss in most affected individuals is severe to profound. Retinitis pigmentosa causes deterioration of the retina and progressive loss of vision, usually to blindness. Disturbances of balance occur with some types of Usher syndrome. Recent MRI evidence has indicated decreased brain and cerebellum size in a sample of Usher syndrome patients, suggesting a broader impact of the disorder than on the visual, auditory, and vestibular systems alone.
An autosomal recessive disorder marked by a combination of congenital sensorineural deafness and retinitis pigmentosa that results in a gradual loss of vision. One variant of the syndrome also interferes with normal balance.