GJB2 and hearing loss disorder: Based on the prevalence of mutations from the previous studies, we selected 7 mutations which show the high frequencies in Korean hearing loss population and designed the method to detect effectively mutant alleles through rapid screening: c.235delC of GJB2, c.919-2A>G and c.2168A>G of SLC26A4 and m.1555A>G of the MT-RNR1 gene.