A clinical trial is about to start that will test a new technique to cure blindness. The possible treatment is based on CRISPR and aims to correct the genes that cause Leber's congenital amaurosis. For the time being it will be tested on 18 adult and child volunteers.

The disease is linked to anomalies present in about 15-20 different genes, which cause a progressive degeneration of photoreceptors in the retina. At the moment there is no cure, apart from an effective gene therapy only on the form caused by the RPE65 gene.

This makes the trial even more important. Existing gene therapy uses a virus to replace the abnormal RPE65 gene with a correct version. What we are going to test, however, acts on the Cep290 gene that causes the Lca10 form of Leber's congenital amaurosis. In this specific case, the researchers will use the new Crispr-Cas9 techniques.

Researchers will inject light-sensitive cells under the retina. CRISPR should replace the abnormal gene, so as to correct the DNA of the retina permanently. If it does work, the disease could stop or even regress. In this way children and adults would get their sight or what remains of it. It is not the first time that Crispr-Cas9 is used directly on the human body. A large number of therapies are being developed that exploit the technique of genetic editing, especially in oncology. In these cases, doctors modify the cells of the immune system so that they affect cancer cells.

Source: wired.it