ECC stands out among pathways affected by DM1 mis-splicing because 3 sequential components are strongly affected by exon skipping (CACNA1S exon 29, RYR1 exon 70, and ATP2a1 exon 22), and a fourth shows abnormal exon inclusion (CLCN1 exon 7a). The gene discussed is CLCN1; the disease is myotonic dystrophy type 1.