05. Exon Skipping

Genes are generally made up of exon sequences (where the As, Cs, Gs and Ts code for protein as described above) and intron sequences (that don't spell out a protein).

The collagen gene involved with DEB (COL7A1) has over a hundred exons with introns in between. For the normal protein to be made, the genetic 'recipe' is read by jumping from exon to exon and ignoring the introns. If one of the exons contains a change that causes the whole protein to be broken, a type of therapy called ‘exon skipping’ might be used to make a protein that leaves out that exon along with the introns. The resulting protein is a bit shorter, but still works. This therapy has the potential to help people with EB and has been used in a different genetic condition called Duchenne Muscular Dystrophy, explained in this animation: