Gene editing is a revolutionary technology but has practical limitations in many cases.
CRISPR is the best known gene editing technology, following upon Zinc-Finger nucleases, TALENs, and meganucleases. Most gene editing technologies, including CRISPR, evolved to destroy the DNA of invading viruses. Researchers harness this biology by modifying the gene editor to target DNA sequences in the human genome.
Gene editing can efficiently knockout genes to address dominant-negative mutations, but it cannot straightforwardly address recessive mutations. Using gene editing to make specific DNA changes or insert new DNA is highly inefficient in most cells since the process relies upon uncontrolled DNA repair pathways that evolved to repress genetic alterations.