Purpose: Usher's syndrome (US) is a group of genetically distinct autosomal conditions, characterized by sensorineural hearing loss accompanied by a retinal dystrophy indistinguishable from retinitis pigmentosa (RP). The purpose of this study was to analyze full-field electroretinography (ERG) and visual acuity (VA) among patients with type I and II Usher's syndrome.
Methods: Electroretinography responses and visual acuity were studied in 22 patients (mean age at test = 26.8+/-16.8 years). Seventeen patients had SU type I and 5 patients were diagnosed as Usher's syndrome type II.
Results: Mean visual acuity was 0.9 logMAR (20/160, Snellen equivalent) for patients with Usher's syndrome type I and 0.4 logMAR (20/50, Snellen equivalent) for patients with Usher's syndrome type II. Scotopic rod and maximal responses were non-detectable in both groups. Mean amplitude for oscillatory potentials was 14.5 microV+/-6.1 in Usher's syndrome type I and 12.6 microV+/-5.2 in Usher's syndrome type II. Cone responses were non-detectable in 95% of the patients with Usher's syndrome I and in 100% of patients with Usher's syndrome II. Mean amplitude for 30 Hz flicker photopic cone response was 3.1 microV+/-4.1 for Usher's syndrome type I and 1.0 microV+/-0.6 for type II with mean implicit time of 34.0 ms+/-6.2 (US I) and 35.8 ms+/-3.1 (type II).
Conclusions: Visual acuity was relatively preserved in both groups, however Usher's syndrome II group showed better visual acuity results. Electroretinography findings were severely reduced in both groups, with most patients showing non-detectable rod and cone responses.
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http://dx.doi.org/10.1590/s0004-27492005000200004 | DOI Listing |
Orphanet J Rare Dis
January 2025
Ophthalmology Department, Centro Hospitalar e Universitário de Coimbra (CHUC), Hospitais da Universidade de Coimbra (HUC), ULS Coimbra, Praceta Prof. Mota Pinto, 3000-075, Coimbra, Portugal.
Background: Syndromic genetic disorders affecting vision can also cause hearing loss, and Usher syndrome is by far the most common etiology. However, many other conditions can present dual sensory impairment. Accurate diagnosis is essential for providing patients with genetic counseling, prognostic information, and appropriate resources.
View Article and Find Full Text PDFProg Retin Eye Res
December 2024
Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands; Department of Ophthalmology, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
Retinitis pigmentosa (RP) is a progressive inherited retinal dystrophy, characterized by the degeneration of photoreceptors, presenting as a rod-cone dystrophy. Approximately 20-30% of patients with RP also exhibit extra-ocular manifestations in the context of a syndrome. This manuscript discusses the broad spectrum of syndromes associated with RP, pathogenic mechanisms, clinical manifestations, differential diagnoses, clinical management approaches, and future perspectives.
View Article and Find Full Text PDFBMC Med
November 2024
Division of Surgery & Interventional Science, Faculty of Medical Sciences, University College London, London, WC1E 6BT, UK.
Background: Predicting which children and young people (CYP) are at the highest risk of developing post-COVID-19 condition (PCC) could improve care pathways. We aim to develop and validate prediction models for persistent PCC up to 24 months post-infection in CYP.
Methods: CYP who were PCR-positive between September 2020 and March 2021, with follow-up data up to 24-months post-infection, were analysed.
PLoS One
November 2024
Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Saguenay, Québec, Canada.
In response to the current challenge in genetic studies to make new associations, we advocate for a shift toward leveraging population fine-scale structure. Our exploration brings to light distinct fine-structure within populations having undergone a founder effect such as the Ashkenazi Jews and the population of the Quebec' province. We leverage the fine-scale population structure to explore its impact on the frequency of rare variants.
View Article and Find Full Text PDFJ Clin Invest
October 2024
Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA.
Usher syndrome type 1F (USH1F), resulting from mutations in the protocadherin-15 (PCDH15) gene, is characterized by congenital lack of hearing and balance, and progressive blindness in the form of retinitis pigmentosa. In this study, we explore an approach for USH1F gene therapy, exceeding the single AAV packaging limit by employing a dual-adeno-associated virus (dual-AAV) strategy to deliver the full-length PCDH15 coding sequence. We demonstrate the efficacy of this strategy in mouse USH1F models, effectively restoring hearing and balance in these mice.
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