'Crispr' gene editing technique may treat inherited blindness

A new gene editing technique which was hailed as the breakthrough of 2015 by Science Magazine has been found effective in preventing retinal degeneration in a type of inherited blindness, a study says.

The researchers focused on inherited retinitis pigmentosa, a degenerative eye disease with no known cure that can lead to blindness. 

They used a technique known as Crispr-Cas9, to remove a genetic mutation that causes the blindness disease. 

Although the study involved rats, it is an important milestone because of its potential implications for humans.

"Our data show that with further development, it may be possible to use this gene-editing technique to treat inherited retinitis pigmentosa in patients," said senior author of the study Shaomei Wang from Cedars-Sinai Board of Governors Regenerative Medicine Institute in los Angeles, US. 

Retinitis pigmentosa is a class of diseases in which patients experience night blindness in the early stages, along with atrophy and pigment changes in the retina, constriction of the visual field and eventual blindness, according to the US National Institutes of Health. 

While rare overall, it is one of the most common inherited diseases of the retina.

Crispr-Cas9, the technique that the researchers used to target retinitis pigmentosa, is adapted from a system that bacteria deploy to disable invading viruses.

In the study, the researchers designed a Crispr-Cas9 system to remove a mutated gene that causes photoreceptor cell loss in the eye. 

They injected this system into young laboratory rats that had been engineered to model a type of inherited retinitis pigmentosa known as autosomal dominant, which involves this mutated gene.

After a single injection, the rats were able to see better compared with controls.

The study was published in the journal Molecular Therapy.