GJB2 and hearing loss disorder: The prevalence of del(125 kb) among unaffected individuals supported it as the fifth most common pathogenic variant associated with hearing loss in China, following c.109G>A, c.235del of GJB2, c.919-2A>G of SLC26A4, and c.299_300del (p.His100ArgfsTer14) of GJB2, according to previously reported studies [36, 37].