New gene-editing technique to correct genetic disorder

Diseases caused by genetic mutation may become easier to cure as scientists have discovered that a gene-editing technique, known as CRISPR, has the potential to correct genetic disorder.

CRISPR holds potential for treating many genetic disorders as it offers an easy way to snip out mutated DNA and replace it with the correct sequence, said the study.

Using the technique, the researchers have cured mice of a rare liver disorder caused by a single genetic mutation.

"What's exciting about this approach is that we can actually correct a defective gene in a living adult animal," said Daniel Anderson, a professor at Massachusetts Institute of Technology.
They researchers offered the first evidence that that the gene-editing technique could reverse disease symptoms in living animals.

The recently developed CRISPR system relies on cellular machinery that bacteria use to defend themselves from viral infection.
The scientists copied this cellular system to create gene-editing complexes that include a DNA-cutting enzyme called Cas9 bound to a short RNA guide strand that is programmed to bind to a specific genome sequence, telling Cas9 where to make its cut.

At the same time, they also delivered a DNA template strand.

When the cell repairs the damage produced by Cas9, it copies from the template, introducing new genetic material into the genome.

This genome editing technique has the potential to treat diseases such as hemophilia, Huntington's disease, and others that are caused by single mutations, said the study.

Scientists have developed other gene-editing systems based on DNA-slicing enzymes, also known as nucleases. But such systems can be be expensive and difficult to assemble.

"The CRISPR system is very easy to configure and customise," said Anderson, who is also a member of MIT's Institute for Medical Engineering and Science.
The study appeared in the journal Nature Biotechnology.