DNA 'Editing' Could Alter Life-Threatening Mutations and Cure Diseases

Scientists discovered a new DNA "editing" technique that could alter life-threatening genome mutations and one day cure diseases.

An inherited liver disease has been cured in living, adult mice using the genome-editing technology. With pinpoint accuracy, scientists corrected a single "letter" of the genetic alphabet that had been mutated in a vital gene involved in liver metabolism.

This advancement could soon lead to clinical trials in patients, given that a similar mutation in the same gene causes the genetic disease in humans.

"Obviously there would be numerous hurdles before such an approach could be used in people, but the simplicity of the approach, and the fact that it worked, really are very exciting," Professor Jennifer Doudna, of the University of California, Berkeley, who helped discover the technique, told The Independent.

The so-called Crispr, a technology that lets researchers make almost any changes to DNA composition in animals and plants, located and corrected the single mutated DNA base pair in a liver gene known as LAH, which can lead to a fatal build-up of the amino acid tyrosine in humans.

It is so accurate - even with 3 billion base pairs of DNA to sift through - that it can be described as correcting a single misspelt word in a 23-volume encyclopedia.

The Crispr technique, coupled with a DNA-sniping enzyme called Cas9, was delivered by high-pressure intravenous injections. It effectively cured mice suffering from the disease by altering the genetic makeup of about a third of their liver cells.

"The fundamental advantage is that you are repairing the defect, you are actually correcting the DNA itself," said Anderson, a researcher from Massachusetts Institute of Technology who led the study.

Crispr was initially discovered in 1987, but scientists did not realize its potential in animals and humans until recently.

As far as human testing goes, scientists are trying to overcome the hurdle of how to safely deliver Crispr to humans, as high-pressure injections are probably too dangerous. Currently, researchers are working on alternative ways to carry out this gene therapy.