Figure 5. Schematic representation of the Cdh23 gene structure and splice variants. Isoform a of Cdh23 is the full-length transcript and contains 69 coding (black) and noncoding (gray) exons [18]. Isoforms b and c were previously reported [29]. Exon 68 encodes part of the cytoplasmic domain of cadherin 23 and is alternatively spliced. Two alternatively splice variants of isoform a, involving exons 5–10 (GenBank EU681829 and EU681830) of Cdh23 were amplified from inner ear and retina cDNA using PCR primers located in the sequence of exons 5 and 13. Cdh23^v-6J is a nonsense mutation found in exon 9, which is absent in one of the alternative splice variants of Cdh23 isoform a.