Mutations in USH2A give rise to two phenotypes: Usher syndrome type 2a (USH2A) and nonsyndromic RP (USH2A associated nsRP). Usher syndrome is the most common form of congenital deafblindness. Patients with Usher syndrome are hearing impaired or profoundly deaf from birth and this can be rehabilitated with hearing aids or a cochlear implant. Furthermore, these patients develop retinitis pigmentosa (RP), a slowly progressive type of retinal degeneration that usually starts in the first or second decade of life. In both USH2A and nsRP patients the disease leads to severe visual impairment and eventually blindness around the 50th-70th year of life. There are no treatment options for the retinal degeneration. We do not know if they also suffer from balance complaints. Currently, genetic therapy for Usher syndrome type 2 and USH2A associated nsRP is in development. But to measure the effect of a (genetic) therapy, it is crucial to know the detailed natural course of the visual and hearing deterioration over time. Several genetic therapy studies for other disorders are currently delayed, because the natural history of the disease has not been studied in detail previously. The main objective is to map the natural course of the visual and hearing deterioration in Usher Syndrome 2 and USH2A associated nsRP for upcoming genetic therapy studies. Secondary objectives are: 1) To determine the necessary type of (combined) examinations, the sample size and length of studies (in years) essential to evaluate future genetic therapy in Usher syndrome. 2) To improve counselling of patients with Usher syndrome type 2 and USH2A associated nsRP with detailed information on the prognosis. 3) To identify additional etiological factors that explain variability in hearing impairment by adding questionnaires and psychophysical audiometric tests; and to assess the vestibular phenotype in Usher syndrome type 2 and USH2A associated nsRP patients. This is a longitudinal, prospective natural history study. The study population consists of healthy human volunteers, 16 - 55 yr old with a confirmed genetic diagnosis of Usher Syndrome type 2 or and USH2A associated nsRP. The main study endpoint is the natural course of the visual and hearing deterioration in Usher Syndrome type 2 and USH2A associated nsRP, over a time span of 4 years. There are no risks associated with participation.
Age range
16 Years – 55 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Change in perceived visual functioning
Timeframe: Baseline, 2 years and study completion at 4 years
Change in perceived handicap due to hearing impairment
Timeframe: Baseline, 2 years and study completion at 4 years
Change in perceived handicap due to dizziness
Timeframe: Baseline, 2 years and study completion at 4 years
Change in lifestyle adjustment due to Usher syndrome.
Timeframe: Baseline, 2 years and study completion at 4 years
Change in perceived health
Timeframe: Baseline, 2 years and study completion at 4 years
Change in the indication of depressive symptoms
Timeframe: Baseline, 2 years and study completion at 4 years
Change in overall condition of the eye
Timeframe: Baseline and every year until study completion at 4 years
Change in visual acuity
Timeframe: Baseline and every year until study completion at 4 years
Change in visual fields area
Timeframe: Baseline and study completion at 4 years
Change in visual fields sensitivity
Timeframe: Baseline and every year until study completion at 4 years
Change in mean retinal sensitivity
Timeframe: Baseline and every year until study completion at 4 years
Change in ellipsoid zone (EZ) area
Timeframe: Baseline and every year until study completion at 4 years
Change in retinal autofluorescence and Robson ring size
Timeframe: Baseline and every year until study completion at 4 years
Change in condition of the retina, macula, optic nerve and ocular vascularization
Timeframe: Baseline and every year until study completion at 4 years
Change in rod- and cone-mediated retinal function
Timeframe: Baseline and every year until study completion at 4 years
Change in retinal function
Timeframe: Baseline and study completion at 4 years
Change in hearing thresholds
Timeframe: Baseline and study completion at 4 years
Change in auditory speech recognition abilities in noise
Timeframe: Baseline and study completion at 4 years
Change in integrity of the outer hair cells
Timeframe: Baseline and study completion at 4 years
Change in integrity of the inner hair cells, the synapse and the first stage on the auditory nerve
Timeframe: Baseline and study completion at 4 years
Vestibular function
Timeframe: 3 years
Function of individual vestibular semicircular canals
Timeframe: 3 years
Function of saccule and utricule of the vestibular organ
Timeframe: 3 years