Gene-editing technique offers new hope

Three groups make breakthrough in possible treatment for Duchenne muscular dystrophy

WASHINGTON • Researchers have succeeded for the first time in reversing a degenerative illness in mice, using a novel gene-editing technique that one day may help cure similar diseases in humans.

Three research groups, working independently of one another, reported in the journal Science in the past month that they had used a powerful method known as CRISPR - clustered regularly interspaced short palindromic repeats - to cure mice suffering from Duchenne muscular dystrophy.

This disorder affects one in every 5,000 baby boys and has a hereditary link.

It is a progressive muscle-wasting disease that puts boys in wheelchairs by the age of 10, followed by an early death from heart failure or breathing difficulties.

"This marks the first time that CRISPR has successfully treated a genetic disease inside a fully developed living mammal with a strategy that has the potential to be translated into human therapy," researchers said.

Duchenne muscular dystrophy arises from genetic mutations that interfere with the production of dystrophin, a protein needed to form healthy muscle.

The gene-editing technique lets researchers cut the DNA of chromosomes at selected sites to remove segments or insert new ones.

They loaded the DNA-cutting system onto a virus that infected the mice's muscle cells and excised the defective stretch of DNA.

Without the defective part, the muscle cells made a shortened dystrophin protein that was nonetheless functional, giving all of the mice more strength.

All three teams have filed for patents.

But plenty of work lies ahead before clinical trials can start.

It is unclear how the human immune system would react to the gene-editing system or to modified dystrophin proteins.

"The advantage of the DNA approach is that the cell has no choice but to make the protein you want," said Dr Amy Wagers of Harvard University, who led one of the studies.

Associate Professor Charles Gersbach of the biomedical engineering department at Duke University cautioned that there is still a "significant amount of work to do to translate this into a human therapy and demonstrate safety".

"But these results coming from our first experiments are very exciting," said Prof Gersbach, the leading scientist on one of the studies.

AGENCE-FRANCE PRESSE, NEW YORK TIMES

A version of this article appeared in the print edition of The Straits Times on January 12, 2016, with the headline 'Gene-editing technique offers new hope'. Print Edition | Subscribe