MAP3K4 and myotonic dystrophy type 1: We also evaluated alternative splicing in urine exRNA of four additional transcripts, MBNL2, MBNL1, CLASP1, and MAP3K4, by ddPCR, and found that inclusion percentages were significantly different in DM1 vs. UA subjects, and values for all four demonstrated a linear relationship to RT-PCR (Fig. 5f, g).