PDZD7 and deafness: Regarding non-syndromic deafness genes, compound heterozygous variants of MYO15A were identified in four sporadic cases (families 1470, 1540, 1479, and 1688); compound heterozygous variants of CDH23 in two sporadic cases (families 1644 and 1528); and compound heterozygous variants of PDZD7 in families 1397 and 1597; all three candidate PDZD7 variants mapped to exon 4 in regions encoding one of the PDZ domains, which are structural anchors that tether the protein to cytoskeletal components [31].