First successful CRISPR gene-editing directly in the blood of a live patient

Patrick Doherty was a healthy, active 65-year-old living County Donegal, Ireland when he was diagnosed with transthyretin amyloidosis, the same rare genetic disease that killed his father. When he visited a doctor, he learned of a new experimental treatment for the condition—with an emphasis on the "experimental" side. As NPR reports:

CRISPR has already been shown to help patients suffering from the devastating blood disorders sickle cell disease and beta thalassemia. And doctors are trying to use it to treat cancer and to restore vision to people blinded by a rare genetic disorder.

But those experiments involve taking cells out of the body, editing them in the lab, and infusing them back in or injecting CRISPR directly into cells that need fixing.

The study Doherty volunteered for is the first in which doctors are simply infusing the gene-editor directly into patients and letting it find its own way to the right gene in the right cells. In this case, it's cells in the liver making the destructive protein.


Doctors infused billions of microscopic structures known as nanoparticles carrying genetic instructions for the CRISPR gene-editor into four patients in London and two in New Zealand. The nanoparticles were absorbed by their livers, where they unleashed armies of CRISPR gene-editors. The CRISPR editor honed in on the target gene in the liver and sliced it, disabling production of the destructive protein.

CRISP-Cas9 is essentially a set of "instructions" that can target incredibly specific gene pairs in DNA and then insert or remove new, corrective information (in this case, the diseased protein). This is the first example of this kind of gene therapy being injected directly into the bloodstream of a living person. And it worked! Or at least, everything looks good so far, and there's no real reason to expect any unfortunate side effects as long as the proteins hit their target, which they did.

He Inherited A Devastating Disease. A CRISPR Gene-Editing Breakthrough Stopped It [Rob Stein / NPR]

Image: National Human Genome Research Institute / Flickr (CC-BY-SA 2.0)