Myotonic dystrophy is a multi-system disorder, characterized by aberrant RNA splicing, which results from the expansion of a CTG tract located in the 3′UTR of DMPK. An important mediator of DM1 pathology is the mutant DMPK RNA encoding the expanded CUG tracts [24], [37]–[39]. This evidence concerns the gene DMPK and myotonic dystrophy.