A new gene-editing technique that allows scientists to snip DNA like a pair of high-precision scissors is also giving them pause: is this technique ready to use on humans, and if so, what happens if the wrong DNA gets cut?
Last week, Cambridge, Mass.-based startup firm Editas Medicine announced that it would be ready to deploy the CRISPR-cas 9 gene-editing process to treat a rare, hereditary form of blindness by 2017.
The announcement by Editas CEO Katrine Bosley didn't say whether the company had already tried it on animal models yet, and it's also not clear whether the technique would be subject to federal rules governing new drugs.
Editas officials were traveling and unavailable for comment this week, according to a company spokesman.
Bosley said at a conference that a CRISPR -- which stands for clustered regularly interspaced short palindromic repeats, essentially segments of DNA containing repeated base sequences -- is a promising cure for treating inherited disorders that are the result of "broken genes," such as Huntington's disease or cystic fibrosis.
The company says it wants to run a clinical trial for Leber congenital amaurosis (LCA) which targets the retina and affects about 600 people in the United States.
The cure would involve injecting benign viruses into photoreceptor cells in the retina. The viruses are engineered to contain the instructions on how to manufacture the components of CRISPR, including a protein that cuts DNA strands at specific locations.
That protein, Cas 9, would then produce an enzyme that cuts away the damaged section of DNA from a specific gene in the patient's photoreceptor cells. The healthy DNA would rejoin and the cells should function normally again, according to Editas' Boswell.
"The most exciting work recently in gene therapy has been diseases to the eye," said Art Caplan, professor of bioethics at New York University. "It's easy to access and you can try one eye as opposed to both and you have a safety model in place."
Still, some experts think CRISPR isn't ready for prime time, or human trials.