Progression of low-frequency sensorineural hearing loss (DFNA6/14-WFS1)

Objective: To assess the audiometric profile and speech recognition characteristics in affected members of 2 families with DFNA6/14 harboring heterozygous mutations in the WFS1 gene that cause an autosomal dominant nonsyndromic sensorineural hearing impairment trait. Design: Family study. Setting: Tertiary referral center. Patients: Thirteen patients from 2 recently identified Dutch families with DFNA6/14 (Dutch III and IV). Methods: Cross-sectional and longitudinal analyses of pure-tone thresholds at octave frequencies of 0.25 to 8 kHz were performed, and speech phoneme recognition scores were assessed. Progression was evaluated by linear regression analysis with and without correction for presbycusis. Results: All individuals showed low-frequency hearing impairment. The 2-kHz frequency was more affected in the Dutch III family than in the Dutch IV family. Progressive hearing loss beyond presbycusis was found in the Dutch IV family and in 3 individuals in the Dutch III family. Annual threshold deterioration was between 0.6 and 1 dB, per year at all frequencies. The speech recognition scores in the Dutch III family showed significantly more deterioration at increasing levels of hearing impairment compared with those in the Dutch IV family. Conclusion: Both families showed an autosomal dominant, progressive, low-frequency sensorineural hearing impairment caused by heterozygous WFS1 mutations.