News analysis: a very narrow road-the application prospects of heritable human genome editing technology from the latest report

　　Xinhua News Agency, Beijing, September 7th News analysis: A very narrow road-the application prospects of heritable human genome editing technology from the latest report

　　Xinhua News Agency reporter Huang Kun

　　An international committee composed of scientists from many countries recently issued a report saying that human genome editing related technologies have not yet reached the standards for safe and effective applications, and the possible future applications must be limited to a very narrow range.

This has triggered heated discussions in the global life science community.

So, what are the opinions of the pros and cons?

Report: Technology is not yet safe and effective

　　The "International Committee on Clinical Application of Human Germline Genome Editing", composed of researchers from the National Academy of Sciences, the Royal Society, Chinese Academy of Sciences and other multinational institutions, released a report entitled "Heritable Human Genome Editing" on related websites on the 3rd, explaining in detail The potential risks and regulatory requirements of heritable genome editing technology.

　　With the rapid development of gene editing technology in the past ten or twenty years, some people have begun to explore the heritable modification of the human genome, that is, the genetic editing of human sperm, eggs and other germ cells. The resulting embryos will have corresponding characteristics. Traits can also be passed on to the next generation.

This has the potential to treat diseases, but it may also be abused for "custom babies", causing safety and ethical concerns. At present, the scientific community generally believes that this is a "red line" that should not be crossed easily.

　　The report puts forward 11 recommendations in this regard. The core content is: to carry out heritable gene editing on human germ cells, the current technology has not yet reached the safe and effective application standards, which may lead to unknowable risks such as editing off-target, so it cannot be applied currently clinical.

If a country allows the application of heritable genome editing technology in the future, it should initially be limited to the prevention of serious single-gene genetic diseases, such as cystic fibrosis, thalassemia, sickle cell anemia, Tessar's disease, etc., and It should only be considered when there are no other options.

　　Regarding the possible future use of the prevention of serious single-gene genetic diseases, the report also defines the clinical transformation pathway and establishes a series of requirements for pre-clinical research evidence, which should ensure that the edited embryos must be as expected before they are used in pregnancy That was edited appropriately.

A biopsy should be used to prove that there is expected editing in all cells undergoing biopsy, and there is no evidence of unexpected editing.

　　Richard Lifton, Co-Chairman of the International Committee and President of Rockefeller University, said: “Any initial application of heritable human genome editing should be advanced step by step and cautiously, with the greatest possible benefit and harm. Favorable balance."

Hot discussion: Necessary restrictions or "too narrow"?

　　Once the report was published, it aroused heated discussions in the global life science community.

Regarding the restrictions set in the report, the term "narrow" is used in related reports on the US "Science" magazine website and the British "Nature" magazine website.

　　Previously, many people in the international scientific community hope to promote the clinical application of heritable human genome editing technology.

Kevin Smith of the University of Abertay in the United Kingdom published in the international journal "Bioethics" in 2019 entitled "Is it time to interfere with human germ cells?"

The article in "A Pragmatic Perspective" stated that gene editing is a practical way to solve certain diseases.

　　Russian researcher Denis Lebrkov said in 2019 that he plans to implant gene-edited embryos into the human uterus, with the goal of modifying genes that cause congenital deafness.

Regarding the new report, Lebrkov said that the allowed application scenarios are too rare to be meaningful. In fact, "the editing of embryonic genomes is prohibited in principle."

　　Sara Norcross, director of the "Progressive Education Trust" in the United Kingdom, which focuses on assisted conception and other fields, believes that "this report is beyond its scientific scope." For human embryo genome editing, "this report sets The conditions are too narrow".

　　But other researchers believe that such strict restrictions are necessary.

Peter Browder, Professor Emeritus of Obstetrics and Gynecology at King’s College London, United Kingdom, said: “This is a detailed report. The first chapter on the science of genome editing is excellent. The report can (or cannot) be presented using heritable genome editing. A suitable high standard."

　　Alta Charro, a bioethicist at the University of Wisconsin-Madison and a member of the World Health Organization's Committee on Related Fields, said: "I welcome this report. It continues to add to the ongoing global scientific discussion on germ cell gene editing. The depth."

Consensus: the demand is still small

　　In general, this report confirms the consensus of the international scientific community that the current demand for genome editing of human embryos is still small.

For some genetic diseases, other reproductive techniques can currently be used to solve the problem. For example, after artificial insemination of multiple eggs, the fertilized eggs are screened to find healthy fertilized eggs to implant in the uterus.

　　Fyodor Urnov, a gene editing expert at the University of California, Berkeley, said that the report carefully sorted out related issues, and the results showed that there are actually very few problems that must be solved by heritable human genome editing.

"An open secret in the field of gene editing is that the editing of human reproduction (cells) is actually looking for solutions with solutions."

　　According to reports, the WHO previously planned to release a report on gene editing of human germ cells before the end of 2020. The report released this time provides suggestions and references for how the WHO can strengthen supervision in related fields.

　　The report released this time calls for the establishment of an independent "international scientific advisory group" on related issues to provide regular updates on related technologies, evaluate recommendations for the use of heritable human genome editing, and review the clinical results of all future regulated applications data.

　　Karen Young, an expert on emerging technologies at the University of Birmingham in the United Kingdom, said that for now, the report just released at least fills a gap in the relevant discussions.