CLCN1 and myotonic dystrophy type 1: The AS findings of this study replicated previous observations regarding DM1 muscle RNA metabolism, such as the abnormal inclusion of exon 7a or retention of intron 2 in muscle-specific chloride voltage-gated channel 1 (CLCN1) transcripts, both triggering nonsense-mediated decay resulting in a severe reduction in functional CLCN1 [46].