Usher syndrome constitutes a group of autosomal recessive disorders characterized by progressive pigmentary retinopathy and sensorineural hearing loss. Phenotypic distinctions are based on auditory and vestibular differences. Persons with forms of Usher syndrome type I (276900) have congenital ... Usher syndrome constitutes a group of autosomal recessive disorders characterized by progressive pigmentary retinopathy and sensorineural hearing loss. Phenotypic distinctions are based on auditory and vestibular differences. Persons with forms of Usher syndrome type I (276900) have congenital severe to profound hearing loss and vestibular dysfunction.
In 2 Pakistani families segregating Usher syndrome type 1F, Ahmed et al. (2001) demonstrated 2 homozygous mutations (IVS27-2A-G, 605514.0001; and arg3 to ter, 605514.0002) in the protocadherin-15 gene (PCDH15; 605514).
In cell culture studies, Rebibo-Sabbah et ... In 2 Pakistani families segregating Usher syndrome type 1F, Ahmed et al. (2001) demonstrated 2 homozygous mutations (IVS27-2A-G, 605514.0001; and arg3 to ter, 605514.0002) in the protocadherin-15 gene (PCDH15; 605514). In cell culture studies, Rebibo-Sabbah et al. (2007) demonstrated that aminoglycosides suppressed translation of several PCDH15 nonsense mutations identified in patients with Usher syndrome type 1F. The aminoglycosides resulted in variable full-length protein levels resulting from partial read-through of the nonsense mutations. Rebibo-Sabbah et al. (2007) postulated that such treatment could potentially delay the progression of retinitis pigmentosa in patients with the disorder. Ahmed et al. (2008) identified mutations in the PCDH15 gene in 7 of 12 consanguineous Pakistani families with USH1F. Six mutations were novel (see, e.g., 605514.0009). The remaining 5 families showed linkage to chromosome 10q21, but no pathogenic mutations in the PCDH15 gene were identified.