REPAIR WITH THE HELP OF CRISPR/CAS9
The CRISPR/Cas9 system is based on an important part of the bacterial defence mechanism against viral infections. The scientists Jennifer Doudna (University of California, USA) and Emmanuelle Charpentier (Max Planck Instituut in Berlin, Germany) discovered in the laboratory that they could modify this defence mechanism themselves. What’s more, they could very precisely cut and paste in the DNA at the desired place. In this way, pieces of DNA can be easily, quickly, cheaply and extremely precisely be processed in all types of cells. CRISPR/Cas9 can enable or disable genes and adjust these in plants, animals and even people.
REPAIR OF THE c.2299delG MUTATION
Carla Fuster Garcia from Valencia, Spain, tries to repair faults/mutations in the USH2a gene with the help of the CRISPR/Cas9 system. Here she concentrates on the most frequently occurring mutation in the USH2a gene: c.2299delG.
Fuster Garcia applied this system to cultivated skin cells of a USH2a patient with the aim to repair the c.2299delG mutation.
With these cell models she demonstrated that the mutation (albeit not really efficiently yet) can be repaired without being confronted with the adverse side-effects in the cell. The next step will be to increase the efficiency of the repair and to test this method in animal models or in a retina cultivated by making use of stem cells.
GENE PROCESSING WITH THE CRISPR/CAS9 TOOL
(Source: SaveSightNow: status and content of study are unknown)
Dr. Williams, who works in the UCLA Stein Eye Institute, uses the CRISPR/Cas9 technology for correcting a mutation in the MYO7A, which causes Usher Syndrome type 1B. MYO7A is a large gene, which makes it difficult to replace using conventional (viral) gene replacement therapy.