Audiometric analysis of a Belgian family linked to the DFNA10 locus.

Abstract

Objective: To report the otologic and audiometric characteristics of a nonsyndromic postlingual sensorineural hearing impairment in a Belgian family linked to DFNA10.

Study design: Retrospective study of the otologic and audiometric data of 17 genetically affected persons.

Setting: Tertiary referral center.

Patients: All members of a Belgian kindred who carried the haplotype linked to the inherited hearing impairment of DFNA10.

Interventions: Diagnostic otologic and audiometric analysis.

Main outcome measures: Pure-tone audiometry.

Results: To find the frequencies that were most affected by the genetic defect, the excess hearing loss of the 17 patients was calculated per frequency in comparison with the respective p50 and p95 thresholds of the normal population.

Conclusions: The genetically affected persons of a Belgian family shared a progressive symmetric sensorineural hearing loss that started in the first to fourth decade. Thirty-five percent of the affected family members had tinnitus, and only one patient had very mild vestibular complaints. At onset, hearing losses were mainly situated at the midfrequencies. With increasing age, all frequencies became affected. The hearing loss was initially mild, with a spontaneous evolution to a moderate or severe hearing impairment. The progression of the hearing loss for the pure-tone average (between 0.5 and 4 kHz) was 1.08 dB/year for this family, compared with 0.50 dB/year and 0.35 dB/year at the 95th and 50th percentiles of the normal population, respectively.