The mode of inheritance is typically autosomal recessive. To date, causative mutations in multiple genes, including MYO7A, USH1C, CDH23, PCDH15, USH1G, CIB2, USH2A, GPR98, WHRN, and CLRN1 have been identified. In addition to clinical variability, there is extensive genetic heterogeneity underlying the condition. Usher Syndrome can be divided by clinical characteristics into 3 types by the age of onset and severity of deafness, imbalance and visual loss. Usher syndrome was first described in 1858 by Albrecht Von Graefe, but was given it’s eponymous name for Charles Usher, a Scottish eye doctor who identified and described the disorder’s hereditary nature and recessive inheritance pattern in 1914. Usher Syndrome is the commonest cause of combined inherited blindness and deafness with an estimated prevalence of 1 in 30,000. The Creative Commons Public Domain Dedication waiver ( ) applies to the data made available in this article, unless otherwise stated in a credit line to the data. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. Further, the value in electroretinographic testing for diagnosis is demonstrated.Ĭongenital hearing loss Electroretinogram Inherited retinal disease Retinitis pigmentosa Usher syndrome.Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. Caution is thus warranted when predicting a visual prognosis in such a patient. The patient demonstrated that the absence of visual symptoms and favorable findings on functional testing on initial presentation might yet belie a future for austere visual loss. They showed that the patient was asymptomatic with only a moderate reduction on ERG testing at the time of diagnosis, but subsequently progressed to an advanced stage of retinal disease with severe visual loss. Our findings documented the long-term progression of Usher syndrome in this patient. We additionally reviewed the ocular findings on two of his siblings also afflicted with Usher syndrome type 2. The patient also had genetic testing performed. Nevertheless, 43 years after his initial examination, he showed severe degenerative changes in the retina.Ī 63-year-old man with Usher syndrome type 2 underwent ophthalmic examination that included visual acuity, optical coherence tomography (OCT), electroretinogram (ERG), fundus photography, and Goldmann visual field testing. Here, we present a case in which an adult patient had neither subjective visual complaints nor ocular findings at the time of diagnosis aside from a moderate reduction in rod and cone function on electroretinogram testing. However, diagnosis may initially be more difficult in cases with limited ocular findings. Patients characteristically experience congenital hearing loss, nyctalopia, reduced visual fields, and ultimately decreased visual acuity. The Usher syndrome phenotype is comprised of ocular and audiologic anomalies.
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