Band-Aid For Genes: Modified EXACT CRISPR/Cas9 Gene Editing Technique Can Repair Point Mutations

Can CRISPR/Cas9 gene editing cure hereditary diseases? Scientists say yes.

Molecular biology experts working at the Christiana Care Health System's Gene Editing Institute have developed a new and improved CRISPR/Cas9 gene editing system, which can repair mutations with a high accuracy.

Scientists have long been working on the mechanism of introducing emergency shut-down switches and failsafes in the CRISPR/Cas9 gene editing technology, Vancouver Sun reported. Eric Kmiec, Director of the Gene Editing Institute at the Helen F. Graham Cancer & Research Institute at Christiana Care, led the team of researchers to develop the EXACT gene editing system that can not only repair the damaged DNA but can also crosscheck whether any unwanted genetic changes were accompanied with the repair.

The research was published in the PLOS One journal in the form of a research article titled Insertional mutagenesis by CRISPR/Cas9 Ribonuclear gene editing in cells targeted for point mutation repair directed by short single-stranded DNA oligonucleotides.

The article described various aspects of the development of the EXACT CRISPR/Cas9 technique, how it can be used for the repair of disease causing point mutations and its real time application in the treatment of diseases, such as the sickle cell anemia or the Gaucher's disease, according to Canada Journal.

A previously published article in the journal Scientific Reports by Dr. Kmiec established the "Band-Aid template" repair mechanism of the CRISPR/Cas9 gene editing method. Further research proved that a single-stranded DNA template conjugated with a pre-assembled CRISPR/Cas9 ribonucleoprotein complex can effectively repair point mutations.

The experiments were done on human cells engineered for the expression of a fluorescent protein only if the point mutation present in the gene responsible for its expression can be repaired. Researchers observed that the EXACT gene editing system could efficiently repair the engineered cells and express functional fluorescent protein.

"If you lose DNA, even one or two bases, even if you fix the point-mutation the gene is disabled, because the gene can no longer code for the proper protein," Dr. Kmiec said. But the CRISPR/Cas9 gene editing was successful in repairing the mutations as well as the errors associated with it, which makes it appropriate for clinical applications.