Researchers used CRISPR/Cas9 to alter a gene involved in HIV entry into cells
Mark Schiefelbein/AP Images
A Chinese scientist’s surprise announcement on the eve of an international human gene-editing summit that he has already created the world’s first gene-edited babies has led to swift condemnation.
Jiankui He is expected to discuss his work November 28 in Hong Kong at the second International Summit on Human Genome Editing. But in an interview with the Associated Press, and in a video posted November 25, He announced that twin girls with an edited gene that reduces the risk of contracting HIV “came crying into this world as healthy as any other babies a few weeks ago.”
That announcement sparked outrage from many researchers and ethicists who say implanting edited embryos to create babies is premature and exposes the children to unnecessary health risks. Opponents also fear the creation of “designer babies,” children edited to enhance their intelligence, athleticism or other traits.
He, on unpaid leave from the Southern University of Science and Technology of China in Shenzhen since February, objects to the term designer baby. “Call them ‘gene surgery babies’ if one must or better yet ordinary people who have had surgery to save their life or prevent a disease,” He and colleagues wrote in a perspective published online November 26 in the CRISPR Journal. But in the video, He said that he realizes his work will be controversial, and he’s willing to take the criticism. Some families need the technology to have healthy children, He said, adding that enhancing intelligence or changing hair or eye color are “not things loving parents do” and should be banned.
Yet many researchers and ethicists argue that He’s editing of the twin’s DNA was not lifesaving nor does it prevent disease. Although the girls’ father has HIV, there are safer ways to protect someone from contracting the virus, which makes the engineering both unnecessary and unethical.
The scientists involved in the announcement “have knowingly violated the ethical norms surrounding this technology,” says Josephine Johnston, a lawyer and bioethicist at the Hastings Center, a bioethics research institute in Garrison, N.Y. The researchers are aware that the scientific community thinks that gene editing is still not safe or appropriate for use in human embryos. “You could even wonder whether they’re doing this for attention,” she says.
At least one prominent gene-editing researcher, Feng Zhang of the Broad Institute of MIT and Harvard, has now called for a moratorium on producing gene-edited babies until researchers can establish safety requirements. Hundreds of Chinese scientists have signed letters condemning the work and calling for greater oversight of gene-editing experiments.
Chinese authorities are also questioning the research. Shenzhen City Medical Ethics Expert Board said in a statement that it is investigating the case, and the hospital cited in documents describing the experiment has denied that the work was done there. He’s university said in a statement November 26 that the work “seriously violates academic ethics and academic norms,” and announced that it will launch an investigation.
He could not be reached for comment.
Disabling a gene
In another video, He said that his group used the gene-editing tool CRISPR/Cas9 to disable the CCR5 gene in the fertilized eggs that produced the babies, called “Lulu” and “Nana” (not their real names). CCR5 produces a protein that allows the most common version of the HIV virus to enter cells. Some people naturally have mutations in the gene that help protect them from HIV infection. Such “gene surgery” has already proven safe in adults with HIV, He said in the video. HIV infection is still a deadly disease and in the developing world, “discrimination increases the devastation,” He said. Gene editing could spare such children from their parents’ fate, He claims.
But the chance that Lulu and Nana would get HIV from their father when their mother doesn’t have the virus is “almost zero. In fact, probably zero,” says Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases in Bethesda, Md. The children could easily avoid HIV infection by other means, so “to put them through the risk of editing their genes as embryos to protect them from infection they can easily prevent themselves, in my mind, is inappropriate at best and unethical at worst.”
Fauci and others are concerned that gene editing may sometimes go astray, damaging other important genes, which could lead to health problems such as cancer later in life. The babies aren’t even guaranteed to escape HIV either: People who have defective CCR5 genes may still be infected with a less common form of the virus. And people with missing or defective CCR5 genes are more susceptible to serious complications from West Nile virus infections, Fauci says.
Even if Lulu and Nana don’t end up with any health problems as a result of He’s genetic tinkering, the experiment is still bad science, says Julian Savulescu, a bioethicist at the University of Oxford. “I liken it to Russian roulette. You can pull the trigger and not kill, but that doesn’t mean what you did was right.”
If He’s claims are true, the work is “monstrous” and could set back gene-editing research, says Savulescu, a self-described fan of the technology. Savulescu has argued that parents may one day have a moral obligation to edit their children’s genes (SN Online: 11/28/17). But this experiment gives no real advantage to the babies and puts them at significant risk of harm, he says. “The risk just wasn’t reasonable in this case. It’s a bad scientific study.”
For now, it’s difficult for researchers to assess how successful the gene editing was.
He’s work has not been published in a scientific journal, and other researchers have not gotten access to any data or DNA samples that could confirm He’s claim. Previous claims of successful gene editing in human embryos in lab dishes have also been met with skepticism (SN Online: 8/8/18).
Verifying the editing would require thoroughly examining, or sequencing, the DNA of the twins and their parents, says Arthur Beaudet, a geneticist at Baylor College of Medicine in Houston. That verification might be possible because the Chinese researchers say that the embryos were sequenced before being implanted into the mother’s uterus and again after birth. But it may be harder to determine whether CRISPR/Cas9 has caused any mutations that may later harm the children, Beaudet says.
Children often naturally develop DNA changes that their parents don’t carry. Beaudet and colleagues are conducting experiments with mice to determine whether gene editing leads to more of these new mutations than usual, he says. Such animal research and work on human embryos that won’t be used to create a pregnancy are necessary before researchers should even consider making gene-edited babies, he says.
Laws governing gene editing vary, with some countries banning it outright and others, including China, having no or less clear policies. In the United States, the Food and Drug Administration cannot accept applications for research in which human embryos are made to have heritable DNA changes. That provision effectively bans the use of the technology to make gene-edited babies or “three-parent babies” who have a small amount of DNA from an egg donor (SN: 12/24/16, p. 22).
Organizers of the first human gene editing summit, held in Washington, D.C., in 2015, said then that gene-editing research on human embryos could go ahead, but only if no babies resulted from the experiments (SN: 12/26/15, p. 12). Since then, other ethics committees have softened that stance saying that if gene editing were shown to be safe, it would ethical to use the technology to correct diseases, but not to enhance health, intelligence or other traits (SN: 3/18/17, p. 7). Public opinion in the United States has also been swinging in favor of gene editing to correct diseases, but not to enhance intelligence (SN Online: 7/26/18).
People have worried for decades that the ability to modify people’s genes could lead to disparities between genetic haves and have-nots, says Marcy Darnovsky, executive director of the Center for Genetics and Society, a nonprofit social justice organization in Berkeley, Calif. She argues that countries should immediately take steps to ban the use of human embryo editing. “We’re living in a time when racism and socioeconomic disparities are increasing dramatically,” Darnovsky says. “The last thing we need is for some biological procedure to fuel the false idea that some groups are biologically superior to others.”
Editor’s note: Feng Zhang is on the board of trustees of Society for Science & the Public, which publishes Science News.
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