CACNA1D and deafness: Ranum et al. (2019) used single cell full-length reverse transcriptional analysis with long-read sequencing to identify novel exons and to reveal the unappreciated splicing diversity among deafness-associated genes. They analyzed 12 deafness-associated genes and detected 20 unannotated exons, including exon 1B of Cabp2 and exons 1B, 22B, 9B, and 31B of Cacna1d. Their work showed that the heterogeneity and complexity of genetic deafness is greater than previously believed and suggested that current genetic tests for deafness are incomplete.