Ahmed et al. (2003) reported 3 families with isolated deafness. Two of the families had no history of nyctalopia, and the funduscopy and electroretinograms were normal in 2 older affected individuals from each family (age range, 13-44 years). ... Ahmed et al. (2003) reported 3 families with isolated deafness. Two of the families had no history of nyctalopia, and the funduscopy and electroretinograms were normal in 2 older affected individuals from each family (age range, 13-44 years). Vestibular responses were intact in affected individuals. Doucette et al. (2009) reported a consanguineous family from Newfoundland, Canada, with isolated hearing loss that was neurosensory, prelingual, and severe to profound. Ancestors of the family had emigrated from England in the early 1800s to settle a fishing 'outport' on Newfoundland's southern coast. Detailed examination of 2 homozygous carriers in middle age showed no evidence of Usher syndrome and no vestibular abnormalities.
In affected members of 2 unrelated families with isolated deafness, Ahmed et al. (2003) identified 2 different homozygous mutations in the PCDH15 gene (605514.0006 and 605514.0007, respectively).
In affected members of a consanguineous family from Newfoundland ... In affected members of 2 unrelated families with isolated deafness, Ahmed et al. (2003) identified 2 different homozygous mutations in the PCDH15 gene (605514.0006 and 605514.0007, respectively). In affected members of a consanguineous family from Newfoundland with isolated deafness, Doucette et al. (2009) identified a homozygous mutation in the PCDH15 gene (V528D; 605514.0010).