What is exon skipping?
If you imagine that the gene is made up of segments (or exons) which ultimately spliced together to make a recipe or message for producing the protein:
A deletion of exon 71 would be considered “in frame” because the 70 and 72 could still joint up and allow transcription. However, a deletion of exons 48 through 50 would be “out of frame” since 47 and 51 do not splice back together to form the message:
The message would become corrupted and the gene product, in this case dystrophin, would be dysfunctional or even totally absent:
The drug Eteplirsen will link 47 and 51 back together again, and in so doing restore the reading frame and facilitate transcription of an altered but hopefully functional gene product:
Does it work?
A clinical study started in August 2011
The preliminary results from this study were very encouraging – the boys who received the drug maintained strength and walking ability and there were no treatment related adverse effects.
What’s the next step?