title: Usher syndrome type III can mimic other types of Usher syndrome.
abstract: Clinical and genetic characteristics are presented of 2 patients from a Dutch Usher syndrome type III family who have a new homozygous USH3 gene mutation: 149-152delCAGG + insTGTCCAAT. One individual (IV:1) is profoundly hearing impaired and has normal vestibular function and retinitis punctata albescens (RPA). The other individual is also profoundly hearing impaired, but has well-developed speech, vestibular areflexia, and retinitis pigmentosa sine pigmento (RPSP). These findings suggest that Usher syndrome type III can be clinically misdiagnosed as either Usher type I or II; that Usher syndrome patients who are profoundly hearing impaired and have normal vestibular function should be tested for USH3 mutations; and that RPA and RPSP can occur as fundoscopic manifestations of pigmentary retinopathy in Usher syndrome.
authors.affiliation: Department of Otorhinolaryngology, University Medical Centre St Radboud, Nijmegen, the Netherlands.
authors.forename: Ronald J E
authors.initials: RJ
authors.lastname: Pennings
authors.forename: Randall R
authors.initials: RR
authors.lastname: Fields
authors.forename: Patrick L M
authors.initials: PL
authors.lastname: Huygen
authors.forename: August F
authors.initials: AF
authors.lastname: Deutman
authors.forename: William J
authors.initials: WJ
authors.lastname: Kimberling
authors.forename: Cor W R J
authors.initials: CW
authors.lastname: Cremers
mesh_terms: D000328:Adult; D001309:Auditory Threshold / Q000502:physiology; D002648:Child; D003937:Diagnosis, Differential; D004584:Electronystagmography; D005260:Female; D005838:Genotype; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D017354:Point Mutation / Q000235:genetics; D012021:Reflex, Abnormal / Q000502:physiology; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology; D012174:Retinitis Pigmentosa / Q000175:diagnosis / Q000235:genetics*; D013577:Syndrome; D014722:Vestibule, Labyrinth / Q000502:physiology
chemical_list: C437067:CLRN1 protein, human; D008565:Membrane Proteins