Characteristics of Retinitis Pigmentosa Associated with and Comparison with in Patients from a Multicentric Usher Syndrome Study Treatrush.

In contrast to , variants in are a minor cause of Usher syndrome type 2, and the associated phenotype is less known. The purpose of the study was to characterize the retinal phenotype of 18 patients (9 male, 9 female; median age 52 years) and compare it with that of 204 patients (111 male, 93 female; median age 43 years) in terms of nyctalopia onset, best corrected visual acuity (BCVA), fundus autofluorescence (FAF), and optical coherence tomography (OCT) features. There was no statistical difference in the median age at onset (30 and 18 years; Mann-Whitney U test, = 0.13); the mean age when 50% of the patients reached legal blindness (≥1.0 log MAR) based on visual acuity (64 years for both groups; log-rank, = 0.3); the risk of developing advanced retinal degeneration (patch or atrophy) with age (multiple logistic regression, = 0.8); or the frequency of cystoid macular edema (31% vs. 26%, Fisher's exact test, = 0.4). and retinopathy were indistinguishable in all major functional and structural characteristics, suggesting that the loss of function of the corresponding proteins produces similar effects in the retina. The results are important for counseling patients, who represent the minor patient subgroup.