Gene editing using CRISPR is set to transform the treatment of genetic disorders. Derived from the immune response of bacteria, it functions by associating an endonuclease, an enzyme which breaks DNA strands, with an RNA molecule, guiding it to a specific location in the genome. Cleaving the target site induces the cell’s DNA repair mechanisms to mend the sequence, correcting mutations responsible for disease in the process. Researchers have used two CRISPR systems, associated with different endonucleases, to fix mutations in the dystrophin gene, responsible for Duchenne muscular dystrophy, a degenerative disease of muscles, including heart tissue (pictured). Treatment with CRISPR restored functional dystrophin in stem cells from human patients and in the offspring of affected mice. One of the longest genes in the human genome, dystrophin can acquire mutations in many places, so building a flexible toolbox of CRISPR systems will be key to successful implementations in human patients.
Written by Emmanuelle Briolat
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