The first in vivo gene editing procedure, performed not in a laboratory cell culture but directly on a patient with Hunter syndrome, has been performed in the United States. The therapy, tested by California-based Sangamo Therapeutics, uses a viral vector that, when injected into the body, uses the CRISPR editing technique to cut the genome at the portion containing the malfunctioning gene and replace it with the correct sequence. Concerns in this case are about possible side effects if the molecular scissors accidentally cut and pasted other areas of the genome, but so far no problems have been reported in the patient.
