DMPK and myotonic dystrophy type 1: Myotonic dystrophy type 1 (DM1) is caused by CTG repeat expansions in the 3′-untranslated region (UTR) of the myotonic dystrophy protein kinase gene (DMPK) [5], while myotonic dystrophy type 2 (DM2) is the result of CCTG tetranucleotide expansion in the CCHC-type zinc finger nucleic acid binding protein gene (CNBP) intron 1 [6].