Editor's note: Li Linxi is an opinion editor at CGTN Digital. The article reflects the author's opinion and not necessarily the views of CGTN.

Usually, people cheer for their first babies, but the report that the world's first gene-edited babies created in China was exceptional. It sparked an international outcry and immediate investigation by the country's health authorities.

Hundreds of Chinese scientists signed an open letter, condemning the experiment as “madness” and "a huge blow to the global reputation of Chinese science".

It was started with a video posted on YouTube on Sunday, in which He Jiankui, an associate professor from Southern University of Science and Technology, announced he had used a gene-editing tool CRISPR-CAS9 (often shortened to CRISPR), to alter a gene in embryos for seven couples with HIV-positive fathers to make the babies free from getting the virus. He claimed the pregnancy was successful and the twin girls were born in November.

He made on Wednesday his first public appearance at a genome forum in Hong Kong after the uproar, saying he was “proud” of his work and “another potential pregnancy” of a gene-edited embryo is in its early stages.

A shocking claim

The claim of He, though yet to be verified, was shocking. The trial is prohibited under Chinese laws that gene-editing experiments on embryos are only allowed for a maximum of two weeks and banned completely for a pregnancy stage. 

The work also violated an international consensus reached in another gene-editing summit in 2015 that CRISPR is considered not suitable to be performed on human embryos for a reproductive purpose at the current status.

In fact, CRISPR, which can insert or deactivate specific genes, was not new. It was first proven successful in 2013 and has only recently been tried on adults to treat deadly diseases.

While gene editing technology has been improved significantly over the past years, according to an official statement by the Genetics Society of China on Tuesday, “The relatively low efficiency on precise modification and potential off-target mutations remain a major concern”.

A step too far for HIV prevention

He Jiankui's claim that the gene-edited babies cannot contract HIV is also believed unnecessary.

“There are many safe and effective ways to prevent HIV transmission to unborn baby and healthy adults without any risk and at very low costs,” Shao Yiming, chief expert on AIDS at the Chinese Center for Disease Control and Prevention, told CGTN.

Sperm washing in case of HIV-positive father, antiretroviral medications treatment in pregnancy, at birth and during breastfeeding in case of HIV-positive mother all proved to be effective in blocking HIV transmission to newborns.

“With proper procedures and antiviral treatments, HIV can be completely blocked from positive father and reduced to less than 1 percent chance from positive mother to infect baby. That means parents carrying the virus can surely give birth to healthy babies,” Shao added.

A trial far from "without risks"

Furthermore, the experiment itself is far from safe.

To explain this, one needs to begin with the very gene that He Jiankui edited – CCR5, a protein on the surface of white blood cells that allows the entrance of HIV into the cell.

Previous studies found that a genetic mutation in the CCR5 gene, better known as CCR5 – Delta 32, resulting in the loss of 32 base pair, can actively block HIV transmission.

It's also found the mutation has a relatively higher frequency in the genetic background of the Caucasoid population (around 1 percent of them carry that mutant), but not in that of Chinese Han.

That creates several risks.

Firstly, the precise creation of an artificial CCR5-Delta 32 mutation is believed to be almost impossible.

“In other words, the experiment could create other artificial mutations that have never been existed in human beings,” Wang Haoyi, a gene-editing expert and a professor at Chinese Academy of Sciences told CGTN, adding “and you have no idea whether those man-made mutations will behave differently than the natural ones.”

Secondly, even if the experiment can successfully introduce the precise mutation of CCR5 – Delta 32, it could generate unforeseen risks due to the simple fact that this mutation is not in the genetic background of Chinese Han.

“The reason there are healthy European people carrying that (Delta-32) mutation doesn't mean you can introduce it into a completely different genetic background group and claimed it safe,” Wang said.

The issue is even severe if you look at it genetically as the yet-unknown consequences of the altered CCR5 gene could get passed on to subsequent generations. That makes the experiment done by He completely different from the IVF.

“The IVF, is merely an assisted reproductive technology that helps sperms and eggs produce healthy babies without changing the gene of embryos,” said Wang.

“For example, when the sperm is not strong enough to swim into the wombs to fertilize the eggs, the IVF can do a favor. So basically it is to make a normal human life that could not exist to exist, containing the natural genetic content,” he added.

The experiment is even different from previous gene therapy as well.

“In the gene therapy we performed on somatic cells of individual patients, you change certain genes for healing. And those changes will be gone when the patients pass away. But the experiment done by He Jiankui, is on the germ cells of embryo, which is heritable and can be brought into the gene pool of human beings. That will disrupt the genetic stability of Mankind,” said Shao Yiming.

A gap between technology and knowledge

However, the potential risks don't include the near arrival of “designer babies”, offspring that are genetically modified, following guidelines set by the parent or scientist, to produce desirable traits.

“Any nation, any civilization which is sane will not do it. It is very clear that at least we should not consider this in next ten to twenty years,” said Wang Haoyi.

“First, you need to perfect the gene editing technology. Second, more importantly, you have to understand genomics much better and to be able to predict whether what you do can achieve the goal you want without causing too much problems. There's a huge gap between what can be done using the technology and the lack of enough knowledge to know the consequences,” he added.

A call for privacy protection

The case is still profoundly concerning. He's work has not been peer-reviewed, though He claimed he had submitted the study to a scientific journal for review at the Wednesday summit. His university said it was in the dark about the research. The hospital named by He that issued him an ethical approval also denied involvement. All those highlighted the weakness of the current regulatory system and the disregard for risks and ethics.

“For scientists themselves, they should become more self-disciplined. They must make sure the experiments are beneficial, and of no harm to study volunteers. They also need to ensure all experiment-related information is fully known to the volunteers and their rights to consent or refuse to participate in the study,” said Shao.

“Supervision at all levels needs to be enhanced with the guidance of experts in the field. Furthermore, rules and laws are needed to be established if there is a blank,” Shao added.

For the twin girls and their parents involved in the experiment, experts believe the whole society should make as much efforts to keep their identities not disclosed to the public.

“I think the babies should not even know they have been edited, if we consider their well-being, they don't deserve to be treated as an experiment,” said Wang Haoyi, adding “and to protect their privacy is the least we can do.”

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