CNBP and myotonic dystrophy type 1: While DM1 results from expansion of a CTG trinucleotide repeat in the DMPK gene on chromosome 19q13.3, a CCTG repeat expansion in the CNBP (also known as ZNF9) gene located on chromosome 3q21.3 and encoding for a ubiquitous protein has been identified in DM2 [16, 17].