DMPK and myotonic dystrophy type 2: DM type 1 (DM1) is caused by the expansion of the CTG trinucleotide repeat at the level of the 3′UTR of the DM protein kinase (DMPK) gene, while DM type 2 (DM2) is caused by the expansion of the CCTG sequence inside the first intron of the CCHC-type zinc finger nucleic acid binding protein (CNBP) gene [158,159].