IMMT and hearing loss disorder: The gene encodes myosin XVa, a 3530 amino acid motor protein involved in the differential elongation of the inner ear hair cells stereocilia [14], Two mutations in MYO15A had previously been identified in Tunisian patients whose hearing impairment loss ranged from severe to profound: c.7395+3G>C and c.4998C>A (p.C1666X) [15].