Expanded CTG repeats in the 3’ non-coding region of the dystrophia myotonica-protein kinase (DMPK) gene in DM1 cause an aggregation of CUG transcripts, which interfere with the regulatory splicing activities of MBNL1 and CELF1 RNA-binding proteins, leading to a misregulation of the alternative splicing of several transcripts [60]. This evidence concerns the gene DMPK and myotonic dystrophy type 1.