DMPK and myotonic dystrophy type 2: Specifically, the underlying molecular cause for DM1 is the existence of a pathological (CTG)n triplet expansion in the 3’UTR of the dystrophia myotonica protein kinase (DMPK) gene [47], whereas (CCTG)n repeats in the first intron of the cellular nucleic acid binding protein/zinc finger protein 9 (CNBP/ZNF9) gene cause DM2 [48].