목적: Unlike prelingual severe auditory neuropathy spectrum disorder(ANSD), etiologies of post-lingual progressive ANSD have not been clearly identified. This uncertainty has led to difficulties in planning a solid auditory rehabilitation. In this study, we tried to identify a molecular etiology of autosomal dominant(AD) progressive ANSD segregating in a big Korean family. We, for the first time in the literature, report a novel AD type ANSD gene. 방법:A big family(SB162) segregating post-lingual progressive hearing loss in adults was recruited and audiological tests including PTA/SA, auditory brainstem responses(ABR) with measurement of cochlear microphonics(CM), EABR, DPOAE/TEOAE and stapedial reflex as well as imaging studies were performed. We performed whole exome sequencing and further Sanger sequencing. Once we identify the convincing candidate gene, we evaluated the expression of the protein in the cochlea using RT-PCR and immunohistochemistry. 결과:We confirmed that the progressive moderate to severe hearing loss with minimal speech discrimination in SB162 was compatible with ANSD as evidenced by no ABR response, but positive CM and DPOAE/TEOAE as well as no anatomical defect of the cochlear nerve. We identified a truncation mutation of a novel gene, TMEM43 to be a molecular etiology of AN/AD in SB162 by recruiting 18 subjects. Strong expression of this gene in the cochlea as proven by RT-PCR and the strong staining of this protein encoded by TMEM43 exclusively in the inner hair cells, not outer hair cells further supported the etiologic role of this mutation for the ANSD in this family. Positive EABR response in SB162 suggested significant maintenance of spiral ganglion neuronal population, implying a favorable response to cochlear implantation. 결론:We report a novel ANSD deafness gene and, for the first time in the literature, provide a nice model for personalized auditory rehabilitation of progressive postlingual ANSD based on the molecular etiology.