Scientists used CRISPR inside an adult patient's body for the first time

For the first time, scientists have used the gene-editing technique CRISPR inside the body of an adult patient, in an effort to cure congenital blindness.

Why it matters: CRISPR has already been used to edit cells outside a human body, which are then reinfused into the patient. But the new study could open the door to using gene editing to treat incurable conditions that involve cells that can't be removed from the body, like Huntington's disease and dementia.

Details: The research was sponsored by the biotech companies Editas Medicine of Cambridge, Massachusetts and Allergan of Dublin, and was carried out at Oregon Health and Science University.

• Scientists led by Eric Pierce of Harvard Medical School injected microscopic droplets carrying a benign virus into the eye of a nearly blind patient suffering from the genetic disorder Leber congenital amaurosis.
• The virus had been engineered to instruct the cells to create CRISPR machinery. The hope is that CRISPR will edit out the genetic defects that cause blindness, restoring at least some vision.
• "We literally have the potential to take people who are essentially blind and make them see," Charles Albright, chief scientific officer at Editas, told the AP.

Doctors had tried using in-the-body editing with a different tool called zinc fingers in 2017. But CRISPR is easier to employ and more effective at making precise gene edits.

• "It gives us hope that we could extend that to lots of other diseases — if it works and if it's safe," National Institutes of Health director Francis Collins told NPR.

Go deeper: Genetic technology's double-edged sword