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DM1 is an autosomal dominant rare genetic disease with variable presentation. It is the most common muscle dystrophy in adults and it is a highly disabling. It is highly disabling as it typically causes severe neuromuscular symptoms, including cardiac conduction defects, myotonia, and progressive muscle weakness and wasting (atrophy). Neuropsychological dysfunction is also a common symptom of DM. The genetic cause of DM1 is well known, namely the accumulation of mutant transcripts containing expanded CUG repeats in the 3 'UTR of the DYSTROPHIA MYOTONICA PROTEIN KINASE (DMPK) gene. CUG repeats aggregate forming ribonuclear foci, the disease hallmark. Toxic RNA retains RNA-binding proteins MBNL, that are thus depleted from their regular cellular targets. Loss of function of MBNL proteins triggers gene misregulation events at the level of transcription, translation, gene silencing, alternative splicing, and polyadenylation of subsets of transcripts. There is ample evidence that MBNL functions are the limiting factors in DM1. Therefore, boosting their expression is a potential therapeutic avenue. Indeed, overexpression of MBNLbnl could rescue disease-associated RNA missplicing and muscle myotonia in a DM mouse model that expresses 250 CTG repeat units from a human skeletal actin promoter (HSALR) (Kanadia et al. 2006). Consistently, compound loss of muscleblind-like function reproduces cardinal features of DM such as reduced lifespan, heart conduction block, severe myotonia, and progressive muscle weakness

Unfortunately, no treatment has yet been specifically developed for DM1 despite intensive efforts.