Prevalence of POU4F3 and SLC17A8 Mutations

Inclusion Criteria: * Age \> 18 years * Patients with a 1. suggestive neurosensory Deafness: The characteristics of the deafness will be determined from the data of the questionnaire, of the interrogation, the examination and results of the tonal audiometry. \*Neurosensory deafness: Audiometrics measurement(difference between the tonal audiometric average loss for the frequencies 0,5, 1, 2 and 4 kHz in air conduction and in osseous conduction) \< 15 dB for each of both ears. * Bilateral symetric: difference between the audiometric thresholds of both ears \< or = 15 dB for at least two frequencies. * Light to severe: The degree of deafness is defined according to the following classification (moderate hearing loss calculated on the frequencies 500 Hz, 1, 2 and 4 kHz): light hearing deficiency from 20 to 40 dB, moderate hearing deficiency of 40 to 70 dB, severe hearing deficiency of 70 in 90 dB and deep hearing deficiency beyond 90 dB. * Whose thresholds frequency by frequency in tonal audiometry (air conduction) are superior to the thresholds of the 90th percentile of the standard ISO 7029. * Without environmental exposition factors. 2. Dominant autosomal transmission diagnosed from one of the following elements: * Deafness at a father and his son * Deafness at a father and his daughter outside a suggestive context of a dominant form X-related. (deep deafness at the father and light to moderate deafness in daughter) * Deafness at a mother and her daughter * Deafness at a mother and her son outside a suggestive context of a dominant X-related(light to moderate deafness at the mother, and deep deafness at the son) * Deafness at a patient whose a dead parent had a sure or likely deafness according to the criteria of diagnosis mentioned previously 3. given the consent to participate at this clinical study Exclusion Criteria: * Suggestive symptom of a polymalformative syndrom * familial Consanguinity * Age \< 18 years * Deafness of transmission or mixed * Deafness of asymmetric or fluctuating perception * Prelingual deep Deafness * Pathology of the ear (otospongiose, disease of Ménière, neurinome of the acoustics)