Multiple exon skipping strategies to by-pass dystrophin mutations

Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Perth, WA 6009, Australia.
Neuromuscular Disorders (Impact Factor: 2.64). 12/2011; 22(4):297-305. DOI: 10.1016/j.nmd.2011.10.007
Source: PubMed


Manipulation of dystrophin pre-mRNA processing offers the potential to overcome mutations in the dystrophin gene that would otherwise lead to Duchenne muscular dystrophy. Dystrophin mutations will require the removal of one or more exons to restore the reading frame and in some cases, multiple exon skipping strategies exist to restore dystrophin expression. However, for some small intra-exonic mutations, a third strategy, not applicable to whole exon deletions, may be possible. The removal of only one frame-shifting exon flanking the mutation-carrying exon may restore the reading frame and allow synthesis of a functional dystrophin isoform, providing that no premature termination codons are encountered. For these mutations, the removal of only one exon offers a simpler, cheaper and more feasible alternative approach to the dual exon skipping that would otherwise be considered. We present strategies to by-pass intra-exonic dystrophin mutations that clearly demonstrate the importance of tailoring exon skipping strategies to specific patient mutations.

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Available from: Steve D Wilton, Jun 30, 2014
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    • "It would therefore be feasible to attempt multiple exon skipping so as to bypass the entire C2D domain of dysferlin using the previously validated AONs. These methods of multiple exon skipping have already been used with success in DMD treatment for the simultaneous skipping of at least 6 consecutive exons [39] [40] [41] [42] [43] [44] [45] [46] [47] [48] [49] [50] [51]. Exon skipping could also be used to remove pseudoexons. "

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    • "When first examining the dystrophin transcripts in cells from the DMD patients, DMD-16ss and DMD-45ss, RT- PCR across the gene lesions failed to yield reproducible amplicons, a result that is inconsistent with skipping of the respective exons. It was considered unlikely that nonsense-mediated decay alone could account for what appeared to be extremely low levels of transcript, as we routinely detect dystrophin transcripts in many different DMD patient cell and tissue samples, under equivalent amplification conditions (Arechavala-Gomeza et al. 2007; Forrest et al. 2010; Fragall et al. 2011; Adkin et al. 2012). Hence, we hypothesized that a catastrophic disruption of pre-mRNA processing may have ablated the dystrophin transcript, downstream of the gene lesion. "
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