In the study, researchers worked with a mouse model that has a debilitating mutation on one of
the exons of the dystrophin gene.
The team led by biomedical engineering professor Charles A. Gersbach used a mouse model suffering from a mutated
exon of the dystrophin gene, programming CRISPR / CAS9 — a bacterial - protein derived process of cutting and pasting DNA portions — to snip out the defective exon.
Not exact matches
The exact mutation varies from patient to patient but in 65 percent
of cases, the
dystrophin gene is missing large sections
of DNA called
exons, which carry the instructions for protein production.
Researchers demonstrate how CRISPR / Cas9 - mediated
exon skipping, or myoediting, may rescue
dystrophin function in a majority
of Duchenne muscular dystrophy patients
Correction
of dystrophin expression in cells from Duchenne muscular dystrophy patients through genomic excision
of exon 51 by zinc finger nucleases.
They observed a 13 % removal rate
of exon 51, which resulted in appropriately localized
dystrophin.
Within the mutational hotspot for
dystrophin,
exons 45 - 55, there are multiple common deletions that maintain the protein's reading frame, leading to the production
of a smaller, but at least partially functional protein.
The
dystrophin gene is very large (79
exons), but much
of the sequence appears to be nonessential.
Although Nelson et al. observed only 2 % genome editing in one experiment, they found the
exon - skipped transcript constituted 59 %
of total
dystrophin mRNA, similar to the 39 % observed by Tabebordbar et al..