Since infancy, the patient had developed recurrent infections of the upper and lower respiratory tract; cystic fibrosis and severe immunodeficiency had been excluded. [jamanetwork.com]

COMMON Features of the Disorder Retinitis pigmentosa Night blindness progresses to more visual loss (e.g. peripheral vision loss) Cataracts Developmental delay Balance problems PROGNOSIS Features of the disorder are confined to sensory issues and other [evolvegene.com]

Abstract Usher syndrome type I is an autosomal recessive disease characterized by profound congenital hearing impairment and vestibular dysfunction followed by the onset of progressive pigmentary retinopathy in childhood or early adolescence. [ncbi.nlm.nih.gov]

Patients with type 2 disease generally are hearing impaired but have no balance problems. All patients develop eye problems that cause difficulty seeing in the dark. [clinicaltrials.gov]