To analyze the phenotype in a 5-generation DFNA13 family with a missense mutation in the COL11A2 gene that causes autosomal dominant, presumably prelingual, nonsyndromic sensorineural hearing impairment.
University hospital department.
Twenty mutation carriers from a large American kindred.
Cross-sectional analysis using pure-tone threshold measurements at 0.25, 0.5, 1, 2, 4, and 8 kHz. The audiometric configuration was evaluated according to an existing consensus protocol. The significance of features relating to audiometric configuration was tested using 1-way analysis of variance. Progression was evaluated with linear regression analyses of threshold-on-age.
Most individuals showed midfrequency (U-shaped) characteristics. The mean threshold in generations IV and V was 44 dB at 1, 2, and 4 kHz (midfrequencies); it was 29 dB at the other frequencies (0.25, 0.5, and 8 kHz). There was no significant progression beyond presbyacusis.
The trait in this family can be characterized as autosomal dominant, nonprogressive, presumably prelingual, midfrequency sensorineural hearing impairment.