목적: The p.P240L is a strong founder allele among Korean arSNHL. CDH23 should be considered as a strong candidate etiology both for pre-lingual and post-lingual arSNHL. Based on the CDH23 alleles with a questionable pathogenic potential in postlingual arSNHL, we propose the phenotypic priority of milder pathogenic DFNB12 allele over strongly pathogenic DFNB12 allele. 방법:From Sep. 2010 to Oct. 2014, subjects with prelingual severe-to- profound or postlingual various degree of arSNHL without phenotypic markers were collected. Sanger sequencing of CDH23 p.P240L was performed on connexin- negative samples without enlarged vestibular aqueducts, followed by targeted resequencing of 134 deafness genes. Four p.P240L-linked STR markers were genotyped in 40 normal-hearing subjects and p.P240L carriers in arSNHL. 결과:We identified significant contribution of CDH23 mutations to both prelingual and postlingual arSNHL, by 3.1%(4/128) and 6.0%(2/33). All affected prelingual subjects showed profound SNHL. On the contrary, postlingually affected subjects carrying one convincingly pathogenic CDH23 mutation in trans with CDH23 variants with a subtle or questionable pathogenicity showed progressive SNHL with serviceable hearing. Most subjects carrying CDH23 mutations had at least a p.P240L allele. Analysis of p.P240L-linked STR markers in these subjects carrying p.P240L revealed a significantly strong association between the p.P240L and a single haplotype (p<0.001). 결론:The p.P240L is a strong founder allele among Korean arSNHL. CDH23 should be considered as a strong candidate etiology both for pre- The p.P240L is a strong founder allele among Korean arSNHL. CDH23 should be considered as a strong candidate etiology both for pre-lingual and post-lingual arSNHL. Based on the CDH23 alleles with a questionable pathogenic potential in postlingual arSNHL, we propose the phenotypic priority of milder pathogenic DFNB12 allele over strongly pathogenic DFNB12 allele.