Consistent with the involvement of MBNL proteins in the RNA gain of function mechanism, Mbnl1 knockdown mice [60] showed DM1-like phenotypes including iridescent cataracts, myotonia and missplicing of muscle transcripts that had been reported altered in DM1 patients such as IR and CLC-1 pre-mRNA [61, 62]. The gene discussed is CLCN1; the disease is Myotonia.