To report on the audiometric characteristics of a large Dutch family linked to DFNA15 with a novel mutation (p.L289F) in POU4F3 (OMIM 602460). Design: Clinical investigation. Setting: Tertiary referral center. Patients: Family members from a large 5-generation pedigree with sensorineural hearing impairment segregating as an autosomal dominant trait. Main Outcome Measures: Cross-sectional and longitudinal analyses of pure-tone audiometric data, and cross-sectional analyses of speech audiometry data. Results: Overall, a flat to gently downsloping audiometric configuration was observed with a progression rate of approximately 0.8 dB/y across most frequencies. Speech recognition scores remained fairly good in relation to age and hearing level compared with a group of patients with presbycusis. Interindividual variability was observed in terms of subjective onset age and audiometric configuration. Two mutation carriers, who reported vestibular symptoms, underwent vestibular examination and showed hypofunction of the vestibular labyrinth. Conclusions: The audiometric phenotype of the Dutch family linked to DFNA15 with a novel mutation in POU4F3 is comparable to that observed in the original Israeli family linked to DFNA15. Relatively good speech recognition scores suggest outer hair cell involvement. DFNA15 may represent a cochleovestibular disorder.

Vestibular examination (electronystagmography with rotatory chair and caloric tests) was performed on 18 carriers and 1 phenocopy carrier in a Dutch family with autosomal dominant nonsyndromic DFNA15. This is the second DFNA15 family worldwide to have a novel L289F mutation in POU4F3. Vestibular involvement appeared to be present in 2 affected individuals according to their medical history. Vestibular examination results in an extended subset of L289F POU4F3 mutation carriers varied from normal to areflexia. DFNA15 is the third cochleovestibular disorder, after DFNA9 and DFNA11, in the autosomal dominant nonsyndromic hearing impairment.