To me this paper sounds like its 2008 but with a single injection. Lot more efficacy over the current weekly dosing regime. 

http://www.sciencedirect.com/science/article/pii/S0960896613008766

In 2008 we first saw the videos of GRDM models seeing the benefits of exon skipping, and now 5 years later we are almost on the verge of large scale trials for different exon skipping. The above paper talks about 21 GRDMs models showing 80%dystrophin after 1 injection and 14 weeks. 

Duplications are a bit further away than GRDM results 

http://www.sciencedirect.com/science/article/pii/S0960896613008663

Its a fast moving world of muscle disorder cures. Hope that it stays that way. Next couple of years should see a effective treatment for all mutation types and then reversal of the loss.