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By Dennis Normile
HONG KONG, CHINA-On the eve of an international summit on genome editing, a Chinese scholar shocked many by claiming to have altered the genomes of twin babies born this month so as to allow modification to all future children – and their children. The purpose of this change is to make children's cells resistant to HIV infection, said scientist He Jiankui of the South Shenzhen University of Science and Technology in China.
The assertion – which is yet to be reported in a scientific article – sparked a string of criticisms today, with some scientists and bioethicists calling this study "premature," ethically problematic and even "monstrous." ". The China Society of Cell Biology has issued a statement describing the research as "a serious violation of the laws and regulations of the Chinese government and the consensus of the Chinese scientific community". And He University, which issued a statement, saying it had launched a research investigation, which could "seriously violate academic ethics and academic standards." "
Other scientists, meanwhile, have asked to see the details of the experiment and its rationale before making a judgment.
He told The Associated Press (AP) that he had modified the embryos of seven couples during fertility treatments, with a pregnancy up to now. In all cases, the father was infected with HIV; all mothers were HIV negative. Its goal was to introduce natural genetic variation in a limited number of people, related to resistance to HIV infection. Specifically, he deleted a region of a cellular receptor called CCR5 using the genome editing technique called CRISPR-Cas9.
The International Summit on the Modification of the Human Genome began Tuesday at this hotel. Many researchers, ethicists and policy makers present at the meeting were informed of He's claim by the media. The organizers of the conference told reporters, at a pre-event briefing, that they were expecting more details.
Scientists are studying the use of CRISPR-Cas9 in treating people with genetic diseases, such as muscular dystrophy and sickle cell disease. It is also interesting to modify the CCR5 receptor in the immune cells of adults already infected with HIV. But all of these cases involved the editing of somatic cell genes, not sperm or egg cells; such changes are not transmitted to the patient's children.
This study apparently went further by modifying the genome of embryos at an early stage, which would affect sperm and eggs (the germ line) and make the change inherited. This work is effectively banned in the United States and many other countries. It is unclear if this fits into the Chinese regulatory environment.
His work has not been published yet. He is scheduled to speak at the summit on gene editing Wednesday, but the organizers did not know he was considering discussing his experience. He put a series of videos on YouTube to justify the experiment, which he calls "gene surgery," and explain how that went. He also invited viewers to send their comments to his lab and to the two babies, named Lula and Nana.
Still, many scientists have stated that the experiment was premature and that the potential benefits were not worth the risk. "Not good, not good, not good. In a world where scientists generally try to become aware of the ethical and social issues related to our work, this report takes us back to the stone age, "said geneticist Darren Griffin of the University of Kent at Canterbury, United Kingdom. said in a statement distributed by the UK Science Media Center (SMC).
The criticism of the claimed achievement was primarily to determine whether the work was scientifically and ethically justified. There are very few documented cases of sperm transmission to an embryo; almost all children born with HIV are infected by their mothers. And there are ways to further reduce the risk of paternal transmission, such as washing sperm. In addition, HIV infection is treatable. "Today, the symptoms of HIV infection can be controlled, and millions of HIV-positive people around the world are living a normal life," said Dusko Ilic, stem cell researcher at King's College London, in another statement. SMC.
"Gene editing itself is experimental and is still associated with untargeted mutations that can cause genetic problems early and later in life, including the development of cancer," says Julian Savulescu, an ethicist at Oxford University in the United Kingdom. "This experience exposes normal and healthy children to the risks of gene editing without any really needed benefit," he says. Sarah Chan, bioethicist at the University of Edinburgh, fears that the premature use of gene editing before examining the social aspects of work "threatens to compromise the relationship between science and society … and could potentially delay the global development of valuable therapies by years. "
The CRISPR pioneer, Jennifer Doudna of the University of California at Berkeley, notes that the work has not been published and called for caution in a statement released today. However, "assuming that independent analysis confirms the news of today, this work reinforces the urgent need to limit the use of gene editing in from human embryos to environments in which a manifest and unmet medical need exists, and where no other medical approach is a viable option, as recommended by the National Academy of Sciences, "writes Doudna.
Apparently anticipating critics, he boldly proclaimed in one of these videos that his group had been deeply thinking about how to help families at risk of genetic diseases. "We think that ethics is on our side of the story," he says, who calls the term "baby designers" an epithet.
Richard Hynes, a cancer researcher at the Massachusetts Institute of Technology in Cambridge, who co-chaired the report of the National Academies of Science, Engineering and Medicine, cited by Doudna, says he has defined "Stringent conditions" before proceeding with the genome revision: There must be a serious and unmet medical need; the effort must be well monitored and sufficiently followed; and it required the informed consent of the parents.
He added that the report of the Nuffield Council on Bioethics of the United Kingdom on the publication of the human genome, published in July, reached similar conclusions. "All of these issues need to be addressed when we hear what he's really done," says Hynes. Alta Charo, bioethicist at the University of Wisconsin in Madison, notes that the National Academies report mentions CCR5 as a potential target for gene editing. That current experience is justified "comes down to a risk-benefit analysis," she says.
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