Exon Skipping Restores Protein in Model of Duchenne Muscular Dystrophy

In a new study in Proceedings of the National Academy of Sciences, researchers from Ludwig Maximilian University of Munich describe their exon skipping analyses within a pig model of Duchenne muscular dystrophy (DMD) lacking DMD exon 52. DMD is caused by mutations in the DMD gene, which lead to the absence of dystrophin and eventually cause progressive degeneration of skeletal musculature and myocardium. While previous studies had led to experimental therapeutic approaches aimed at correcting the reading frame of the DMD gene, they were limited in its ability to completely restore dystrophin in all cardiomyocytes. "Thus, there is a need for DMD animal models that predict the best possible therapeutic outcome of exon skipping strategies," the authors write. In their paper, the authors find that in DMD patients and in a corresponding pig model, an additional deletion of DMD exon 51 alongside the deletion of DMD exon 52 leads to the expression of an internally shortened dystrophin, as the transcript is reframed. This presence of dystrophin was confirmed by immunohistochemistry, western blot analyses, and mass spectrometry.