MBNL1 and Myotonia: For example, HSALR, Mbnl1−/− and adr mice all exhibit myotonia and increased frequency of oxidative fibers (16,22,63), and we previously reported that 24% of changes in gene expression in HSALR mice are likely due to myotonia-dependent transcriptional reprogramming, as evidenced by parallel changes in adr mice (40).