Single-molecule, full-length transcript isoform sequencing reveals disease-associated RNA isoforms

CZ: key principle underlying his work on heart disease: alternative splicing of mRNA generates different isoforms to increase diversity and complexity.

Half of dilated cardiomyopathy cases are familial, 1/3 of those have mutations in splicing factor RBM20, resulting in particularly severe disease.

What are the exact transcript isoforms that are deregulated in RBM20 mutants? To investigate, Chenchen generated iPSC-derived mutant cardiomyocytes, and sequenced their cDNA with MinION.

Chenchen’s team identified over 30,000 transcripts, of which 30% were putatively novel, with an average of 2 isoforms per gene from just a single tissue type.

They identified 38 mis-spliced transcript isoforms in 34 genes enriched for cardiac function, and revealed significant differences in expression of many isoforms, including several RBM20 targets.

Compared to conventional RNAseq, Chenchen notes that this approach could directly point to aberrant isoforms, instead of requiring any reconstruction.