X-linked deafness is a mixed deafness syndrome with congenital fixation of the stapedial footplate. The DFN 3 gene was mapped to the Xq 21 region by linkage analysis and by identification of deletion in both syndromic and nonsyndromic patients.1
The hearing loss in the affected person has a conductive and sensorineural component. A large conductive component of more than 30 to 40 dB reflects stapes ankylosis, which becomes gradually smaller toward the higher frequencies. Smaller conductive losses of 20 dB are believed to be the result of a widened vestibule, leading to a loss of energy of fluid wave transmitted to the cochlea.2 Sensorineural loss is caused by cerebrospinal fluid changing pressure in the perilymphatic and endolymphatic component of the cochlea.