China could be just over a year away from clinical trials of a new gene-editing therapy with an unprecedentedly high level of precision that could protect it from causing undesired genetic mutations.

The cutting-edge technology targets and swaps individual “letters” in a patient’s DNA with extreme precision to avoid cuts to DNA strands. Scientists with the Chinese Academy of Sciences’ Shanghai Institutes for Biological Sciences claim in academic journal Nature that the therapy could help cure two-thirds of more than 50,000 diseases, including some of the deadliest cancers caused by misplaced DNA letters.

Until now, the existing genome-editing method has worked like a shotgun, breaking up large numbers of genome strands and sometimes missing its intended target, causing unnecessary damage to cells.

The South China Morning Post has reported that Chinese geneticists have been racing to develop a new gene editor that will be safe for everyone. Clinical trials, first on primates and later on human volunteers, will reportedly commence only one or two years from now.

Earlier, researchers at Sichuan University conducted similar experiments including injecting edited white blood cells into patients with late-stage lung cancer.

The widely-used CRISPR (clustered regularly interspaced short palindromic repeats) technology, the most popular tool for gene editing, depends heavily on a cellular self-repairing mechanism to repair broken gene strands, and mutations caused by editing are extremely difficult to detect and may actually trigger additional bouts of cancer.

The new tool can mark the mutated genes and make them glow under a microscope, and with this technology, researchers can single out mutated genes.

Chinese biologist He Jiankui has shown no remorse despite the backlash after his morally questionable experiments led to the birth of the world’s first gene-edited babies last year. Photo: Twitter

Chinese scientists with the Shanghai institute also have a solution involving a modification of CRISPR’s protein structure to reduce or eliminate off-target effects. However in the meantime they are worried that the hefty backlash evoked by their peer He Jiankui, who altered the genes of human embryos that led to the birth of twin girls, with one other treated baby as yet unborn, has drawn the ire of Chinese policymakers and made a crackdown on all gene-editing research programs imminent.

Last week, China’s National Health Commission released a draft regulation requiring all gene-editing tests on humans to be approved in advance by the central government. In the past, approval by a provincial health authority was sufficient.