To reveal splicing alterations that may be relevant to the DM1 phenotypes, we deployed our RT-PCR screening platform to identify which mis-splicing events documented in the HSALR and MBNL1 knockout mice (FBV/n strain) were similarly altered in mice (C57BL6/129/OLA/FVB strain) displaying a milder DM1 phenotype. This evidence concerns the gene MBNL1 and myotonic dystrophy type 1.