Cell degeneration is not a primary causer for Connexin26 (GJB2) deficiency associated hearing loss

► We coincidentally examined cochlear development and hearing loss in Cx26 KO mice. ► Deafness is congenital and occurs at all frequencies before cell degeneration. ► Cell degeneration is only visible in middle-high frequency regions in the adult cochlea. ► Cx26 deficiency associated deafness is not resulted from cell degeneration.