Sex-Related Hearing Impairment in Wolfram Syndrome Patients Identified by Inactivating WFS1 Mutations

This study examined the audiovestibular profile of 11 Wolfram syndrome patients (4 males, 7 females) from 7 families, with identified WFS1 mutations, and the audiometric profile of 17 related heterozygous carriers of WFS1 mutations. Patients with Wolfram syndrome showed a downsloping audiogram and progressive hearing impairment. None of the carriers had sensorineural hearing loss. Two patients with missense (non-inactivating) mutations in WFS1 had normal hearing and mild symptoms of Wolfram syndrome and were excluded from the analyses. Of the identified patients with inactivating WFS1 mutations, 5 female patients were significantly more hearing impaired than four male patients (p < 0.05). Female patients showed hearing impairment progressing by 1.5–2.0 dB HL per year for the low frequencies and 4.0–4.5 dB HL per year for the mid and high frequencies. The age of onset (90% phoneme recognition score) was 21 years and the onset level 78 dB HL. The deterioration rate was 4.0% per year and the deterioration gradient 1.4% per dB HL. One of the 6 examined patients had vestibular areflexia.