RNA-Seq analysis shows differential exon usage of MDS-related genes. (A-D) A total of 81 564 exons were tested in 9069 genes for differential exon usage between normal and mutant groups. A total of 48 835 exons were excluded, being not testable or present in genes with less than 2 testable exons. A total of 423 exons from 350 genes were found to be differentially used at the 0.05 false discovery rate level (ie, adjusted P < .05; Table 2 shows the complete list). A total of 282 of these 423 exons (67%) had higher usage in the mutant group relative to a healthy person. A total of 56 genes contained more than one significant exon. Screenshots of fitted exon counts indicate that 4 genes, specifically ASXL1, CBL, EZH1, and RUNX3, contained at least 1 exon showing differential usage between SF3B1 mutants (red) and normals (blue). Positive (+) and negative (−) signs indicate the strand, giving the 3′ and 5′ ends of the gene. Area in magenta represents the differentially used exon.