Until now the CRISPR system, also known as “genetic scissors”, was only tested in the laboratory. Now for the first time, CRISPR has been used on a man with an inherited form of blindness.
“We literally have the potential to take people who are essentially blind and make them see,” Charles Albright, chief scientific officer of Editas Medicine, told the AP.
This is not a miracle but could become a reality if all goes as planned. A team from Oregon Health & Science Institute has used the CRISPR system to treat a patient with an inherited form of blindness – Leber congenital amaurosis- caused by a genetic mutation that prevents the production of a protein needed to convert light into signals for the brain.
This disease cannot be treated with standard gene therapy, where a replacement gene is provided because it is too large to be incorporated into incapacitated viruses, the classical route for the transport of new genes into cells.
Suppression of the mutation responsible for the disease
“As a result the doctors decided to treat this patient with CRISPR to remove the mutation responsible for the disease, making two incisions on each side of the gene in the hope that the ends of the DNA would reconnect and the gene could function normally,” explains the Associated Press.
The surgical technique of the CRISPR system, in this case, was quite simple: under general anesthesia, three drops of a liquid containing the CRISPR system were administered to the patient through a hair-sized tube directly under the retina at the back of the eye where the light-sensitive cells are located.
The risk of unintentional changes in other genes
The scientists gave themselves one month after the intervention to ensure that this process was really able to restore sight. However, all previous animal tests showed that this treatment could correct the cell’s defective genetic code.
Although the CRISPR system represents a great hope for gene therapy, there is a risk that using the system to process one gene may cause involuntary changes in other genes with unknown and not necessarily controllable consequences. Therefore, this “first” in the field of medicine is closely followed by the scientific community.