MBNL1 and myotonic dystrophy type 1: For instance, MBNL1 is responsible for the regulation of ABLIM1 (actin-binding LIM protein 1) exon11 and CLCN1 (muscle chloride channel) exon7a splicing, which are dysregulated due to sequestration of MBNL1 in the expansion RNAs in DM1.