CLCN1 and Myotonia: In particular, DMPK- and ZNF9-induced alteration of CLCN1 transcription have been demonstrated in several mouse models of DM1 and DM2, and is likely responsible for the observed myotonia (Charlet-B et al., 2002; Mankodi et al., 2002; Chen et al., 2007; Lueck et al., 2007; Wheeler et al., 2007; Hao et al., 2008).