Scientist reports first gene editing of humans | Science News for Students

Scientist reports first gene editing of humans

The newborn twins could pass on their tweaked genes to future generations
Nov 29, 2018 — 10:53 am EST
a photo of Chinese researcher Jiankui He presenting data on his claim of creating two gene-edited babies on November 28

This week, researcher Jiankui He gave scientists their first glimpse of data from the creation of two gene-edited babies. Many in the scientific community have decried the work.

S.C. Leung/Sopa Images/Lightrocket/Getty Images

A Chinese scientist made a surprise announcement this week. It was just as an international conference to discuss human gene-editing was to begin. Jiankui He reported he had already done what these scientists would be talking about: He created the world’s first gene-edited babies. These twin girls are being called Lulu and Nana (not their real names).

On November 28, He offered more details to the scientists attending that conference. Lulu and Nana’s parents were one of seven couples recruited from a group of patients with HIV. That’s the virus behind AIDS (acquired immunodeficiency syndrome). What’s more, at least one more woman from the group is pregnant with a gene-edited baby.

Reactions were swift. Most scientists condemned what He claimed to have done. Altering the genes in human embryos to create babies is premature, they said. It also threatens exposing the children to unneeded health risks, they added.

The announcement also points to a big new change in genetic research. This work doesn’t just repair a defect in some adult. It forever changes an individual’s DNA. Later, that edited DNA can be passed down to future generations.

He’s team is aware that the scientific community thinks that gene editing is still not safe or appropriate for use in human embryos, says Josephine Johnston. She is a lawyer and bioethicist at the Hastings Center. This research institute in Garrison, N.Y., focuses on bioethics — issues of whether certain biological research should be done, even when it’s possible to do.

The scientists involved in tweaking the babies’ genes “have knowingly violated the ethical norms surrounding this technology,” Johnston says. “You could even wonder whether they’re doing this for attention.”

But in a news interview with the Associated Press, and in a video posted November 25, He said his team had altered genes designed to cut the risk that either of the newborn twins could get HIV. This gene-tweaking was done on embryos in a lab dish. Those embryos were later implanted in the twins’ mom.

The resulting babies “came crying into this world as healthy as any other babies a few weeks ago,” He reported. Since February, this scientist has been on unpaid leave from the Southern University of Science and Technology of China. It’s located in Shenzhen.

Criticism came fast

Many researchers and ethicists expressed immediate outrage at He’s claim. They said the science behind this was too new to ensure gene editing of human babies was safe. Opponents also said the move could be seen as the first step in making “designer babies” — children edited to enhance their intelligence, athletic ability, hair color or other traits.

He rejects the term designer baby. He and his colleagues wrote a commentary that appeared online November 26 in the CRISPR Journal. “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,” the team said. But in his video, He said that he realizes his work will be controversial. He also said he’s willing to take the criticism. Some families need gene-editing to have healthy children, He said.

But he agreed that enhancing IQ or changing hair or eye color are “not things loving parents do.” He, too, maintains that those types of changes should be banned.

Yet He’s editing of the twin’s DNA was not lifesaving, argue many researchers and ethicists. It doesn’t even prevent disease. Although the girls’ father has HIV, there are safer ways than gene editing to protect someone from picking up the virus, they claim. And that makes tweaking the girls’ genes both unnecessary and unethical.

So far, He’s work has not been published in a scientific journal. Moreover, other researchers have not gotten access to any data or DNA samples that could confirm his new claim.

Researchers at the Hong Kong meeting who saw the talk aren’t convinced that He provided enough evidence to show the editing was successful and didn’t damage other genes. Earlier work by others has indicated that some cells in embryos may be incompletely edited or escape editing entirely.

Indeed, there would be no way to know if every cell in an embryo was edited equally without examining the DNA in each cell separately, says Dennis Eastburn. He’s a molecular geneticist who was not at the summit. Eastburn is chief science officer of Mission Bio. It’s located in South San Francisco, Calif.

an illustration of a hand using tweezers to remove part of a larger-than-life DNA chain
Tweezers are way too big to pick out a portion of genetic material for editing. But this artists’ depiction of the idea gets the point across that scientists can now snip out and replace one or more genes to alter how a body develops.

Should the practice be stopped?

He performed his embryo-tinkering largely in secret. Not even the university where he worked had been aware of the study.

At least one prominent gene-editing researcher, Feng Zhang, has now called for a ban on gene-edited babies — at least until researchers can set requirements for how it can be done safely. Zhang works at the Broad Institute of MIT and Harvard University in Cambridge, Mass.

Hundreds of Chinese scientists have also signed letters condemning He’s work. They called for greater oversight of gene-editing experiments, too.

Wensheng Wei works at Peking University in Beijing, China. At the Hong Kong meeting, Wei asked He why he had worked in secret and had undertaken what he knew was controversial work to create the babies. He didn’t answer.

Government leaders in China are also questioning the research. Shenzhen City Medical Ethics Expert Board issued a statement. It said the board would investigate. Documents describing the gene-editing work on the twins mentioned a hospital where it was done. That hospital now denies the work was done there.

He’s university said in a statement on November 26 that it too condemns his gene editing of babies. It said that research “seriously violates academic ethics and academic norms.” That university also said it will launch a probe into He’s new work.

Editing not needed by girls, critics argue

CCR5 is the name for a gene. It produces a protein that allows the most common version of the HIV virus to enter cells. Some people are born naturally with mutations — altered forms of this gene. Those natural mutations help guard against HIV infection in these people.

He and his team used the gene-editing tool CRISPR/Cas9 to disable the CCR5 gene in two fertilized eggs. Those eggs would develop into Lulu and Nana.

HIV infection is still a deadly disease. “Discrimination [against people with HIV] increases the devastation,” He said. Gene editing could spare such children from their parents’ fate, He said.

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. He should know. Fauci is 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, he says. So “to put them through the risk of editing their genes as embryos . . . in my mind, is inappropriate at best and unethical at worst.”

Fauci and others are concerned that gene editing could cause problems. It might damage other important genes, for instance. Such genetic harm might lead to cancer or some other health problems later in life. And the babies aren’t even guaranteed to escape HIV. People with defective CCR5 genes may still be infected with an uncommon form of HIV. And people with defective CCR5 genes are more susceptible to serious complications from infection with the West Nile virus, Fauci notes.

Even if Lulu and Nana don’t end up with any health problems, this experiment should not have been done, says Julian Savulescu. He is a bioethicist in England at the University of Oxford.

So far, no one has shown that He even did was he claims to have done. But if his claims are true, that work would be “monstrous,” says Savulescu.

He has argued in the past that parents may one day have a moral obligation to edit their children’s genes — if it can be done safely and would save their children from some grave illness. But the new experiment gave the babies no real health advantage, while putting them at risk of harm, Savulescu says. “It’s a bad scientific study.”

Editor’s note: Feng Zhang is on the board of trustees of Society for Science & the Public, which publishes Science News for Students.

Power Words

(for more about Power Words, click here)

academic     Relating to school, classes or things taught by teachers in formal institutes of learning (such as a college).

AIDS     (short for Acquired Immune Deficiency Syndrome) A disease that weakens a body’s immune system, greatly lowering resistance to infections and some cancers. It is caused by the HIV germ. (See also HIV)

bioethics     A code of conduct for research in biology and medicine. To be ethical, people should treat others fairly, avoid cheating or dishonesty in any form and avoid taking or using more than their fair share of resources (which means, to avoid greed). Bioethics applies this idea to research. It focuses on how to avoid putting others at risk without first alerting people to the potential dangers — and having them choose to accept such risks without coercion. A person who works in this field is known as a bioethicist.

cancer     Any of more than 100 different diseases, each characterized by the rapid, uncontrolled growth of abnormal cells. The development and growth of cancers, also known as malignancies, can lead to tumors, pain and death.

Cas9     An enzyme that geneticists are now using to help edit genes. It can cut through DNA, allowing it to fix broken genes, splice in new ones or disable certain genes. Cas9 is shepherded to the place it is supposed to make cuts by CRISPRs, a type of genetic guides. The Cas9 enzyme came from bacteria. When viruses invade a bacterium, this enzyme can chop up the germs DNA, making it harmless.

cell     The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells. Most organisms, such as yeasts, molds, bacteria and some algae, are composed of only one cell.

colleague     Someone who works with another; a co-worker or team member.

commentary     (in science) An opinion piece, often written to accompany — and add perspective to — a paper by others, which describes new research findings.

CRISPR     An abbreviation — pronounced crisper — for the term “clustered regularly interspaced short palindromic repeats.” These are pieces of RNA, an information-carrying molecule. They are copied from the genetic material of viruses that infect bacteria. When a bacterium encounters a virus that it was previously exposed to, it produces an RNA copy of the CRISPR that contains that virus’ genetic information. The RNA then guides an enzyme, called Cas9, to cut up the virus and make it harmless. Scientists are now building their own versions of CRISPR RNAs. These lab-made RNAs guide the enzyme to cut specific genes in other organisms. Scientists use them, like a genetic scissors, to edit — or alter — specific genes so that they can then study how the gene works, repair damage to broken genes, insert new genes or disable harmful ones.

develop     To emerge or come into being, either naturally or through human intervention, such as by manufacturing. (in biology) To grow as an organism from conception through adulthood, often undergoing changes in chemistry, size and sometimes even shape.

discrimination     (in social science) An attitude of prejudice again people or things based on a bias about one or more of their attributes (such as race, sex, religion or age). It is not based on the actions of an individual but instead based on yet-unfounded expectations that are being applied broadly to a whole group.

DNA     (short for deoxyribonucleic acid) A long, double-stranded and spiral-shaped molecule inside most living cells that carries genetic instructions. It is built on a backbone of phosphorus, oxygen, and carbon atoms. In all living things, from plants and animals to microbes, these instructions tell cells which molecules to make.

egg     The unfertilized reproductive cell made by females.

embryo     The early stages of a developing organism, or animal with a backbone, consisting only one or a few cells. As an adjective, the term would be embryonic — and could be used to refer to the early stages or life of a system or technology.

ethics     (adj. ethical) A code of conduct for how people interact with others and their environment. To be ethical, people should treat others fairly, avoid cheating or dishonesty in any form and avoid taking or using more than their fair share of resources (which means, to avoid greed). Ethical behavior also would not put others at risk without alerting people to the dangers beforehand and having them choose to accept the potential risks.

gene     (adj. genetic) A segment of DNA that codes, or holds instructions, for a cell’s production of a protein. Offspring inherit genes from their parents. Genes influence how an organism looks and behaves.

gene editing     The deliberate introduction of changes to genes by researchers.

generation     A group of individuals (in any species) born at about the same time or that are regarded as a single group. Your parents belong to one generation of your family, for example, and your grandparents to another. Similarly, you and everyone within a few years of your age across the planet are referred to as belonging to a particular generation of humans.

genetic     Having to do with chromosomes, DNA and the genes contained within DNA. The field of science dealing with these biological instructions is known as genetics. People who work in this field are geneticists.

genome     The complete set of genes or genetic material in a cell or an organism. The study of this genetic inheritance housed within cells is known as genomics.

HIV     (short for Human Immunodeficiency Virus) A potentially deadly virus that attacks cells in the body’s immune system and causes acquired immune deficiency syndrome, or AIDS.

infection     A disease that can spread from one organism to another. It’s usually caused by some type of germ.

infectious     An adjective that describes a type of germ that can be transmitted to people, animals or other living things.

intelligence     The ability to collect and apply knowledge and skills.

IQ     Short for intelligence quotient. It’s a number representing a person’s reasoning ability. It’s determined by dividing a person’s score on a special test by his or her age, then multiplying by 100.

moral     A code of behavior that aspires to do what’s right (not wrong) and to treat others as you would hope they would treat you.

mutation     (v. mutate) Some change that occurs to a gene in an organism’s DNA. Some mutations occur naturally. Others can be triggered by outside factors, such as pollution, radiation, medicines or something in the diet. A gene with this change is referred to as a mutant.

norms     The attitudes, behaviors or achievements that are considered normal or conventional within a society (or segment of society — such as teens) at the present time.

novel     Something that is clever or unusual and new, as in never seen before.

online     (n.) On the internet. (adj.) A term for what can be found or accessed on the internet.

premature     Too early; before something should occur. Premature births, for instance, are when babies are born weeks or months early — potentially before they are ready for life on their own, outside their mom’s protective womb.

protein     A compound made from one or more long chains of amino acids. Proteins are an essential part of all living organisms. They form the basis of living cells, muscle and tissues; they also do the work inside of cells. Among the better-known, stand-alone proteins are the hemoglobin (in blood) and the antibodies (also in blood) that attempt to fight infections. Medicines frequently work by latching onto proteins.

risk     The chance or mathematical likelihood that some bad thing might happen. For instance, exposure to radiation poses a risk of cancer. Or the hazard — or peril — itself. (For instance: Among cancer risks that the people faced were radiation and drinking water tainted with arsenic.)

summit     (in geology) The uppermost part of a mountain or hill, or (verb) the act of climbing and reaching that uppermost point. (in public policy) A meeting between officials of some organization or governments, often with the goal of negotiating new rules, policies or treaties.

syndrome     Two or more symptoms that together characterize a particular disease, disorder or social condition.

technology     The application of scientific knowledge for practical purposes, especially in industry — or the devices, processes and systems that result from those efforts.

trait     A characteristic feature of something. (in genetics) A quality or characteristic that can be inherited.

virus     Tiny infectious particles consisting of RNA or DNA surrounded by protein. Viruses can reproduce only by injecting their genetic material into the cells of living creatures. Although scientists frequently refer to viruses as live or dead, in fact no virus is truly alive. It doesn’t eat like animals do, or make its own food the way plants do. It must hijack the cellular machinery of a living cell in order to survive.


Journal:​ J. He et al. Draft ethical principles for therapeutic assisted reproductive technologiesCRISPR Journal. Published online November 26, 2018. doi:10.1089/crispr.2018.0051.

Video: The He Lab. About Lulu and Nana: Twin girls born healthy after gene surgery as single-cell embryos. YouTube. November 25, 2018.

Video: The He Lab. Why we chose HIV and CCR5 first. YouTube. November 25, 2018.