Transcriptional analysis of patients with splicing factor mutations. (A) Comparison of levels of U2AF1 mRNA between U2AF1 mutants, WT cases, and WT cases with low expression of U2AF1 (red, blue, and green colors, respectively). The mean expression level is indicated by the dashed line. (B) Exon skipping levels in 3 genes comparing U2AF1 mutants, WT, and WT with low expression levels (red, blue, and green bars, respectively). (C) Validation of RNAseq results on exon 7 of the CEP164 gene using an independent set of patients by RT-PCR. (D) Comparison of exon skipping levels between patients bearing mutations in different spliceosomal factors: SF3B1, SRSF2, U2AF26, and U2AF1. ATR, ataxia telangiectasia and Rad3-related.