One of the inventors of gene editing says scientists should proceed cautiously before testing it in people.

Feng Zhang

Citing the risk of deadly mistakes, a leading researcher speaking at MIT Technology ReviewsEmTech conferenceon Tuesday said the risks of gene editing need to be better understood before the technology can be used in medical studies.

Feng Zhang, a researcher at MIT, helped invent a powerful new way to alter DNA that he compared in his talk to a search-and-replace function for the genome.

Several startups have already sprung up to turn the technology into new kinds of gene-therapy drugs, including CRISPR Therapeutics and Editas Medicine, a biotechnology company that Zhang cofounded last year with venture capitalists who invested $43 million.

These companies hope to correct diseases, like cystic fibrosis, caused by faulty DNA. In other cases, Zhang said, changing a persons DNA could provide a protective effectfor instance, conferring immunity to HIV.

The concept is very powerful, but to make any correction in the body is very challenging, he said.

Looming over researchers is the 1999 death of Jesse Gelsinger, a volunteer in an early gene therapy study in Pennsylvania. That failure dealt a huge setback to genetic drugs. Later it was shown that such treatments, even when they work, could sometimes cause cancer by making unwanted changes to a persons genome.

One of the early lessons from gene therapy is to go slowly, said Zhang. The lesson is that we need to understand a system carefully before putting it into a person.

Gradually, however, gene therapy has staged a comeback. In 2012, a treatment called Glybera was the first to be approved in Europe. Its not yet for sale in the U.S., but numerous gene treatments are being tested in patients.

Original post:

EmTech: Risks of Gene-Editing Drugs Need Study, Pioneer Says