U.Va. researchers respond to reports of first CRISPR-modified babies

Chinese scientist claims to have used CRISPR technology to genetically edit embryos

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Despite his assertions, He has not released any data from or documentation of his experiment.

Tyra Krehbiel | Cavalier Daily

On Nov. 26, 2018, Chinese doctor He Jiankui claimed that he genetically modified the embryos of twin girls born earlier that same month. As the first person to genetically alter human babies, He’s announcement caught many scientists — including those at the University — by surprise.

“I was a bit shocked that someone actually did it,” said Mazhar Adli, associate professor of molecular biology and genetics. “Technically we know it is doable, but we were not expecting someone was going to do it now.”

During his presentation at the Second International Summit on Human Genome Editing in Hong Kong, He briefly detailed his research with expectant couples where at least one parent suffered from HIV. Through in vitro fertilization techniques and directed CRISPR-Cas9 deletions in the gene CCR5 — which codes for surface proteins that the HIV can exploit to gain entry to white blood cells — he made the embryos immune to the HIV. CRISPR-Cas9 is a gene editing tool that can cause targeted deletions in DNA sequences, enabling the removal of harmful mutations or portions of the genome that code for certain proteins.

Despite his assertions, He has not released any data from or documentation of his experiment — a reason for concern for many in the scientific community, including Anindya Dutta, professor of biochemistry and molecular genetics at the University. 

“I would like to see the actual data, to see if what he is claiming is true,” Dutta said. “Unless you look at the data, it is hard to decide whether or not the claims are accurate.”  

According to Dutta, he was surprised someone had conducted such an experiment when there are still questions in the scientific communities about the ethics and safety of such procedures.

Shenzhen Harmonicare, the hospital from which He allegedly received approval for the experiment, and Southern University, the school with which He is affiliated, stated that his research was not in keeping with their professional, academic and ethical principles. 

“I feel very uncomfortable about someone going off on his or her own without lengthy deliberations about the wisdom of this or the lack thereof,” Biology Prof. George Bloom said. “As far as the biology is concerned, I think if you can make a case for anything, the genetic engineering this Chinese scientist engaged in should be used for genetic diseases and even that should undergo very cautious scrutiny.”

Furthermore, He did not adhere to certain widespread ethical and scientific guidelines. He edited the germline of the twins — meaning that the changes in their genome will be passed onto future generations. Until now, gene editing in humans have been confined to somatic, or bodily cells, and in many countries — the United States among them — have prohibited genetically editing human embryos. 

While China has passed no such law, many Chinese scientists refuse to edit human embryos, and when He unveiled his experiment, 122 Chinese scientists denounced his actions, a sentiment Adli shares.

“This is not medically justified,” Adli said. “He performed these experiments on human embryos and human bodies, and these traits will be passed onto future generations forever; we cannot change them, and now these babies will be in a different position socially … What he has done is a wreckless experiment on human embryos and the human body.”

Questions about the efficacy of CRISPR-Cas9 raised moral and scientific issues as well. Though the use of CRISPR has become more routine in laboratories in the past decade, there are still issues regarding its efficiency. Firstly, according to an article in The New York Times, there is still the possibility that CRISPR-Cas9 could cause unwanted mutations in other areas of the genome. 

Secondly, since the CRISPR-Cas9 complex functions independently on each of the cells in the embryo, there is the possibility that copies of the target gene — in this case CCR5 — can remain intact rather than undergo deletion. He said that CRISPR-Cas9 edited both copies of the CCR5 gene in only one twin; the other twin is a mosaic — meaning her cells contained an untouched copy of CCR5. In other words, the latter twin is still vulnerable to HIV.

In fact, Dutta mentioned that for the twin that is a mosaic, He may have actually caused harm by exposing her to CRISPR-Cas9 unnecessarily.

“He did not help the patient and actually made things worse by exposing her to something that could be dangerous, the results of which might only be manifest 30 years later,” Dutta said. “The CRISPR-Cas9 editing system has a bad habit of making breaks in the genome, and some of those breaks could lead to things like cancer down the road.”

However, all concerns about technology aside, many members of the scientific community challenge the very premise of He’s experiment. While other researchers continue to investigate germline editing in order to combat genetic diseases with no other known cure, there are relatively reliable drugs available to treat HIV.

“He is justifying his efforts, saying that these babies will be at least somewhat protected from HIV,” Adli said. “That is true, but in a few years, we will develop a new drug for HIV that will completely cure HIV AIDS, but these girls are genetically modified now. If there are any side effects, who is going to tell these people that they did these things on them, but all of their peers are now able to survive without the side effects and without having been genetically modified.”

In addition, since treating HIV does not require altering the genome, He’s work could be considered as genetically enhancing the twins. However, according to Adli, much of the scientific and medical communities have ardently advised against conducting such types of research, and many countries have banned the use of genetic modification technologies for enhancing human traits.

“This is under the category of enhancement… [but] medical treatment versus enhancement is a very gray area,” Adli said. “What is enhancement and what is normal, and what is normal anyway?... I think in the future, humans and society will use these tools to enhance certain traits, and whether it is ethical or not is the discussion we should be having.”

Since late November, researchers have begun to consider the implications of He’s announcement.

“I definitely do not want a huge outcry in the general public that will shut down all genome editing experiments, including somatic genome editing experiments,” Dutta said. “They are much safer… Somatic genome editing should be looked at as something very different from germline editing.”

Some scientists, including Bloom and Adli, hope that this will spark more conversations about biotechnology and that the public will become more informed about new advancements in the future.

“There needs to be a lot of interplay between scientists and the general public,” Bloom said. “It’s not just something a scientist or a physician should be able to do on his or her own.”

Adli also cited the need for citizens and policy makers to be involved in the regulations accompanying genome editing moving forward. 

“There is one silver lining, which is that there is now more public engagement in this discussion, which I think is very critical,” Adli said. “These issues should be discussed not only by scientists, but also by the general public, by physicians, by law and policy makers. Everyone needs to get involved in the discussion, and so I think that this has been a good first step.”

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