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Ophthalmologic findings in Usher syndrome type 2A
A Van Aarem1, M Wagenaar, A J Pinckers
1Department of Otorhinolaryngology, University Hospital Nijmegen, The Netherlands.
Ophthalmic Genetics
|December 1, 1995
Summary
Usher syndrome type II (USH2) patients show significant eye condition variability despite a presumed genetic homogeneity. Ophthalmologic findings, including visual acuity and fundoscopic appearance, worsen with age, impacting Usher syndrome management.
Area of Science:
- Ophthalmology
- Genetics
- Audiology
Background:
- Usher syndrome type II (USH2) is a genetic disorder characterized by hearing loss and retinitis pigmentosa.
- Genetic heterogeneity was investigated in a Dutch cohort of USH2 patients.
Purpose of the Study:
- To investigate the ophthalmologic variability in Usher syndrome type II patients.
- To analyze the genetic basis and clinical presentation of USH2 in a Dutch population.
Main Methods:
- Ophthalmologic examinations were performed on 37 patients (24 familial, 13 isolated).
- Gene-linkage analysis was used to confirm USH2A in familial cases.
- Fundoscopic findings were classified into Type A and Type B.
Main Results:
- Despite genetic homogeneity, significant ophthalmologic variability was observed, even within families.
- Corrected visual acuity decreased with increasing age.
- The prevalence of Type A fundoscopic findings (attenuated vessels, bone corpuscles) increased with age.
Conclusions:
- The USH2A gene is likely the primary cause of USH2 in the Dutch population studied.
- Age-related progression of ophthalmologic symptoms is a key feature of USH2.
- Understanding this variability is crucial for managing Usher syndrome type II.