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Experts beat the science behind the CRISPR baby experiment



He Jiankui at the Human Genome Editing Conference on November 28, 2018 in Hong Kong.
Image: AP / Kin Cheung [19659004] A few genetic experts claim that the controversial human gene-editing experiment of Chinese scientist He Jiankui was not only unethical, but also scientifically profoundly flawed. The experiment is unlikely to work as intended, and the two girls produced by the project are now facing uncertain health risks.

The authors of the new commentary on PLOS Biology, the geneticists Wang Haoyi and Yang Hui from the Chinese The Academy of Sciences (CAS) made no swear words, as they the gene-editing experiment of the Chinese geneticist He Jiankui with a severe rebuke offended.

"[We] believe that there is no sound scientific reason to perform this type of gene editing on the human germline, and that the conduct of him and his team is a grave violation of both the Chinese provisions and the law Consensus of the international scientific community, "write the authors. "We strongly condemn their actions as extremely irresponsible, both scientifically and ethically."

At the Second International Summit of Gene Cultivation, held in Hong Kong last November, he shocked the world by announcing the birth of twin girls whose DNA he created with the CRISPR / Cas9, an adjunct professor at the Southern University of Science and Technology Gene editing tool had changed. In collaboration with embryos, he deactivated the CCR5 gene, which encodes a receptor that, together with another receptor, serves as an access to the HIV virus to penetrate and infect white blood cells. The goal of the project was to give the virus a built-in genetic immunity. He said the procedure was medically necessary because the girl's father was HIV-positive.

Wang and Yang have explored the reasons behind the project and the experiment. Although the full details of the work have not yet been announced, the authors said that the experimental design and data presented at the Hong Kong Summit had "shown grave lapses both scientifically and ethically". The authors saw the need to write the comment article "because we believe that a responsible study and discussion of this event requires a good understanding of the scientific facts."

The procedure is not medically necessary because it requires HIV / AIDS. Detecting infection in the conception phase by adhering to established assistive reproduction protocols. Regarding the post-partum infection risk, "most people simply do not have the risk of exposure to HIV," adding, "treating early embryos does not benefit babies while acting serious on multiple fronts Risk. "

These" multiple fronts "involved a poor understanding of how the lack of the CCR5 gene could affect Asian individuals, particularly the way in which the introduced allele or mutant gene has unforeseen health risks This seemingly random mutation may occur naturally, and scientists have looked into the effects on Europeans, who for the most part appear to be healthy, meaning that the CCR5 mutation does not protect individuals from all HIV strains This mutation has not been thoroughly studied in Chinese populations, so e s "very difficult to predict the risk of introducing the [CCR5 allele] into a Chinese genetic background," wrote the author.

"Although he claimed that there was a long-term health succession plan, there are no details of who finances or takes responsibility for medical problems," she wrote.

Wang and Yang described the quality of the science he used as" inferior. " For example, during his presentation in Hong Kong, the scientist He said he had used data on CCR5 knockout in mice to determine whether the deleted gene would trigger "undesirable genetic, physiological, or behavioral consequences," as in He's Slide described.

"That's absurd," Wang and Yang wrote, "it's not possible to answer that question by simply comparing the histology staining of four different tissues without quantification and performing two simple behavioral tests on mice," adds Science was added "very poor and superficial".

Other problems revealed by Wang and Yang included certain experiments that could not be replicated, and lack of attention to the potential problems caused by off-target mutations (where CRISPR / Cas9 might unintentionally alter other genes) ) and the potential for mosaicism (in which an individual has acquired several different genomes). Wang and Yang wrote that He's approach was not mature enough to detect possible off-target mutations, and that "he probably underestimated the speed of the mosaic and the risk of damaging genetic changes."

The authors concluded a comment text is urged by the international community of scientists and regulators "to initiate as broad a discussion as possible to develop the criteria and standards for genome processing in the human germ line for reproductive purposes." Then you pass laws and build the necessary institutions for oversight and enforcement, the authors wrote.

"I fully agree with the authors," wrote Brendan Parent, a bioethicist at the NYU School of Medicine, in an email to Gizmodo. "He Jiankui contradicted all principles of responsible research to be the first to be tempted. He did not go through sufficient approval channels, his consent procedure for the parents was misleading and his justification was wrong.

The parent, who is not involved in the new comment paper, said that parents with HIV could not have affected a child by the virus through in vitro fertilization (IVF) and preimplantation genetic testing (PGT), in which Embryos are examined for disease before implantation.

"We have no clear idea of ​​the health risks these children will have, because they do not know how genetic manipulation affects development, and that they are a mosaic for the CCR5 gene that should be excised Gene, "Parent Gizmodo said. "In addition, we do not know what the mere process of germ line editing of a human embryo does, even if it was a technical success for the intended gene editing."

The good news about all this is the overwhelming consensus that he has done something bad and that action must be taken to prevent it from ever happening again. Let's hope that this consensus actually leads to action.


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