NGS Assessment of Congenitally Deafned Children and Neonatal Deafness Screnning

Inclusion Criteria: * Retropective study Inclusion criteria: * Age of onset of deafness between 0 and 17 years * With a hearing loss of one or two senses with, on the ear most affected, a hearing loss more than 40 dB in mean audiometric loss in behavioural audiometry * Availability of detailed information in Appendix 1: History, history and course of disease, associated symptoms, otoscopy data, radiology, treatments and hearing aids implemented. * Availability of DNA samples stored in an existing collection. * Consent to participate in the study (non-opposition) by the legal representative Exclusion Criteria: * Exclusion criteria: * Child with a known cause of observed deafness (meningitis, post-surgery or drug iatrogenic, trauma, infections, tumor) * Family not willing to participate in the study Prospective study Inclusion criteria: * Age of the child 0 to 6 months including corrected age having had on at least one of the two ears a lack of acoustic otoemissions and a lack of response in automated PEA, and a threshold of PEA at least on one ear at more than 40 dB. * Availability of detailed information in Appendix 2: Personal history, family history of deafness, associated symptoms, tympanometry, otoscopy data, neonatal deafness test data. * Collection of the consent of the legal representative Exclusion criteria: · Family not willing to participate in the study