[The CRISPR system can correct or modify the expression of genes responsible for hereditary diseases]

A new technology, called CRISPR, derived from the immune system of bacteria, uses a Cas9 nuclease and a guided RNA complementary to a 20 nucleotides sequence of a gene to induce double strand DNA breaks. This permits to modify specifically the targeted gene in plant, animal and human cells. Variants of the technique also permit to reduce or increase the expression of a selected gene. This technology may thus be used not only to understand the role of a gene but also to develop therapies for hereditary and acquired diseases.