DM is an autosomal dominant disorder, which arises from 2 different mutations: DM1, determined by 50-1000 CUG triplets in the 3′UTR of DMPK gene [18,41] and DM2, caused by 75–11000 expansions of the tetranucleotide CCTG in the first intron of ZNF9. [18,42]. This evidence concerns the gene CNBP and myotonic dystrophy type 2.