DFNA9

DFNA9 (Deafness Autosomal Dominant 9) is an autosomal dominant hereditary hearing loss which is associated with vestibular deterioration. The most recent genotype-phenotype correlation studies have been conducted more than 15 years ago. Meanwhile, emerging and valuable vestibular tests have been added to the vestibular test battery. These tests were not available at the time of the correlation studies. The aim of this study is to carry out a prospective cross-sectional study on symptomatic and presymptomatic affected carriers of the Pro51Ser (P51S) Coagulation Factor C Homology (COCH) mutation in order to correlate vestibular data using the complete vestibular test battery with the known data on hearing and vestibular function in relation to age.

In 2014 radiologic lesions were detected at one or more semicircular canals using CT and MR imaging of temporal bone in subjects carrying the p.P51S mutation in COCH. These lesions are believed to present at more advanced stages of the hearing and vestibular deterioration. Since then, other authors have described similar lesions in advanced non-genetic hearing and vestibular impairment as well. The purpose of this study is therefore to assess the radiologic investigation using CT and MR imaging of temporal bone to all subjects presenting with bilateral vestibulopathy, using the Barany criteria, compared to the p.P51S population.