CDH23 and hearing loss disorder: Mutations in CDH23 and PCDH15 may lead to both NSHL (DFNB12 and DFNB23, respectively) and Usher syndrome type 1 (USH1D and USH1F, respectively) characterized by both congenital hearing loss and childhood retinitis pigmentosa (Astuto et al., 2002; Hu et al., 2018; Zhan, Liu, & Chen, 2015).