By Dennis Normile
HONG KONG, CHINA—On the eve of an international summit here on genome editing, a Chinese researcher has shocked many by claiming to have altered the genomes of twin baby girls born this month in a way that will pass the modification on to any future children—and to their children. The alteration is intended to make the child’s cells resistant to infection by HIV, the AIDS virus, says the scientist, He Jiankui of the Southern University of Science and Technology in Shenzhen, China.
The claim—yet to be reported in a scientific paper—initiated a firestorm of criticism today, with some scientists and bioethicists calling the work “premature,” “ethically problematic,” and even “monstrous.” The Chinese Society for Cell Biology issued a statement today calling the research “a serious violation of the Chinese government’s laws and regulations and the consensus of the Chinese scientific community.” And He’s university issued a statement saying it has launched an investigation into the research, which the university says may “seriously violate academic ethics and academic norms.”
Other scientists, meanwhile, asked to see details of the experiment and its justification before passing judgement.
He told the Associated Press (AP) that he altered embryos for seven couples during fertility treatments, with one pregnancy resulting thus far. In all cases, the father was infected with HIV; all the mothers were HIV-negative. He’s goal was to introduce a genetic variation occurring naturally in a limited number of people that is linked to resistance to HIV virus infection. Specifically, He deleted a region of a cellular receptor known as CCR5 using the popular genome-editing technique called CRISPR-Cas9.
The International Summit on Human Genome Editing begins here on Tuesday and many researchers, ethicists, and policymakers attending the meeting first learned of He’s claim through media reports. Organizers of the conference told reporters at a pre-event briefing they were awaiting further details.
Scientists are investigating the use of CRISPR-Cas9 as a treatment for individuals suffering from genetic diseases, such as muscular dystrophy and sickle cell disease. There’s also interest in altering the CCR5 receptor in the immune cells of adults already infected with HIV. But all these cases involved gene editing of so-called somatic cells, not sperm or eggs; such changes are not passed on to the patient’s children.
This study apparently went a step further, altering the genome in early stage embryos, which would affect sperm and eggs—the germline—and make the change heritable. Such work is effectively barred in the United States and many other countries. Whether it fits within China’s regulatory environment is not clear.
He’s work has not yet been published. He is scheduled to speak at the summit on gene editing on Wednesday, but organizers were unsure whether he planned to discuss his experiment. He put a series of videos on YouTube to justify the experiment, which he calls “gene surgery,” and explain how it was done. He also invited viewers to send comments to his lab and to the two babies, named Lula and Nana.
Yet many scientists said the experiment was premature and the potential benefits not worth the risk. “Not good, not good, not good. In a world where scientists, by and large, try to be aware of ethical and social issues surrounding the work that we do, this report takes us back to the Stone Age,” said geneticist Darren Griffin of the University of Kent in Canterbury, U.K., in a statement distributed by the U.K. Science Media Centre (SMC).
Criticism of the claimed achievement focused on whether the work was scientifically and ethically justified. There are very few cases of documented transmission from sperm to an embryo; almost all children born with HIV become infected from their mothers. And there are ways to further reduce the risk of paternal transmission, for instance by washing the sperm. Moreover, HIV infection is treatable. “Today, symptoms of HIV infection can be kept under control and millions of HIV-positive people worldwide live a normal life,” Dusko Ilic, a stem cell scientist at King’s College London, said in another SMC statement.
“Gene editing itself is experimental and is still associated with off-target mutations, capable of causing genetic problems early and later in life, including the development of cancer,” says Julian Savulescu, an ethicist at the University of Oxford in the United Kingdom. “This experiment exposes healthy normal children to risks of gene editing for no real necessary benefit,” he says. Sarah Chan, a bioethicist at The University of Edinburgh, worries that the premature use of gene editing prior to consideration of social aspects of the work “threatens to jeopardize the relationship between science and society … and might potentially set the global development of valuable therapies back by years.”
CRISPR pioneer Jennifer Doudna of the University of California, Berkeley, notes that the work has not been published and urged caution in a statement released today. However, “Assuming that independent analysis confirms today’s news, this work reinforces the urgent need to confine the use of gene editing in human embryos to settings where a clear unmet medical need exists, and where no other medical approach is a viable option, as recommended by the National Academy of Sciences,” Doudna wrote.
Apparently anticipating the criticism, He boldly proclaimed in one of this videos that his group has reflected deeply on how to help families facing risks of genetic diseases. “We believe ethics are on our side of history,” says He, who calls the term “designer babies” an epithet.
Richard Hynes, a cancer researcher at the Massachusetts Institute of Technology in Cambridge who co-chaired the National Academies of Sciences, Engineering, and Medicine report that Doudna referred to, says it laid out “stringent conditions” that should be met before undertaking genome editing: There had to be a serious, unmet medical need; the effort should be well-monitored and with sufficient follow-up; and there had to be informed consent of the parents.
He adds that the United Kingdom’s Nuffield Council on Bioethics’s report on human genome editing, released in July, reached similar conclusions. “All these questions need to be looked into when we hear what he’s actually done,” Hynes says. Alta Charo, a bioethicist at University of Wisconsin at Madison, notes the National Academies report does mention CCR5 as a potential target of gene editing. Whether the current experiment is justified “comes down to a risk-benefit analysis,” she says.
Source: Science Mag