Chinese scientists develop new ‘ultra precise’ gene-editing tool

Hong Kong: A team of Chinese researchers has developed a new gene-editing tool that differs in approach to the most popular CRISPR-Cas9 gene-editing therapy, saying the new method is ultra-precise, safe and has potential to treat some genetic diseases, the media reported on Wednesday.

CRISPR-Cas9 acts as “molecular scissors” that can cut the two strands of DNA in the genome and relies on the cell’s self-healing mechanism to repair.

However, the new tool, known as “base editors”, fixes specific sites in the genome without cutting the double helix, reports South China Morning Post.

Their study was published in the peer-reviewed journal National Science Review that comes under the auspices of the Chinese Academy of Sciences.

“It means we have established a system of our own, which is essential for clinical and commercial application,” said Yang Hui, a researcher with the Centre for Excellence in Brain Science and Intelligence Technology of the Chinese Academy of Sciences.

The “base editing” has already become a major tool to treat genetic diseases.

Last year, a patient in Britain with T-cell leukaemia was treated with a base-edited cell therapy – the world’s first application of this technology.

“As gene-editing tools continue to advance, more rare diseases will be able to go to clinical trials and be solved by scientists and biomedical companies,” Hui said.

The first base editors were proposed in 2016 by a team led by David Liu at Harvard University.

The study is also important for the development of disease models in basic research and in the field of gene therapy, according to the authors.

Base editors could correct four of the most common types of misspellings that occur in DNA, accounting for about 30 per cent of all known disease-causing DNA errors.

“CRISPR-Cas9 is like a pair of scissors that can cut the DNA, which may result in the deletion or insertion of base pairs, while base editing is like a pencil and eraser that can erase one base and change it into another,” said Yang.