MIT: editing an embryo gene in China could cause new mutations and not develop HIV resistance


In November 2018, an employee of the Southern University of Science and Technology of Shenzhen, He Jianqui, announced the birth of the first twin girls in China with the edited gene. The aim of the experiment was to achieve the ability to resist HIV. However, scientists from MIT in their study concluded that this goal was not achieved, and editing the gene could cause additional mutations.   Genome Editing Specialist at the University of California, Fedor Urnov, said Jiankui’s claim to reproduce the prevailing CCR5 variant “is a flagrant misrepresentation and deliberate misrepresentation.”   A MIT study says that Chinese scientists were unable to reproduce the prevailing variant of CCR5. Instead of copying the desired “Delta 32” variation, they created new versions of the genes, and they can cause mutations.       In addition, one of the embryos had edits for both copies of the CCR5 gene (one from each parent); in the other, only one gene was edited, giving at best partial resistance to HIV.       Chromatograms also demonstrate that embryos are “mosaic”, which means that different cells in the embryo were edited differently. Thus, only some of their cells can have the HIV resistance gene; it also means that some may have undetected “inappropriate” changes that could potentially cause health problems.       In addition, as the authors of the work emphasized, the Chinese biophysicist ignored many ethical and scientific standards. They indicate, in particular, that a couple with an HIV-positive spouse agreed to take part in the experiment under some pressure. Modern assisted reproductive methods (for example, sperm washing) ensure safe reproduction for HIV-positive men and women, avoiding both horizontal (between partners) and vertical (between parent and embryo / fetus) transmission, which makes embryo editing unnecessary. Moreover, Chinese IVF doctors may not have been aware of the father’s HIV status or that the embryos were genetically modified.   Interestingly, in concluding the article, the author connects his project with the HIV epidemic in Africa. The fact is that many uninfected children of African mothers with HIV suffer from a syndrome that makes them more susceptible to various childhood illnesses. The author claims that editing the genome may be a “new strategy” against this. In an email that Jiangqui sent to Craig Mello, a biologist at the University of Massachusetts, on November 22, 2018, he thanked the 2006 Nobel Prize winner in medicine (“for discovering RNA interference — the effect of damping the activity of certain genes”) for his suggestions on the topic. “Again, I will not tell people that you know what is happening here,” the biophysicist wrote. Mello said that he had never given advice on how to write an article.   According to geneticist Hank Greeley, even if every child in the world was offered the option of editing genes, he would have begun to exert a significant influence on the spread of HIV infection only after 20-30 years, and by this time much more effective methods of fighting should have been developed with an epidemic and modernized existing ones.   Scholars cite Junkuy’s handwritten unpublished material from a source this year. An article by a Chinese researcher was titled “Birth of twins after editing the genome for HIV resistance,” but she never saw the light of day. The second manuscript was devoted to laboratory studies of human and animal embryos. Both drafts were edited at the end of November 2018, just at the moment when the scientist made a statement about the birth of twins.  See also: “Genetic engineering of human embryos will become safe and effective in two years” Jiankui He announced the birth of the world’s first children with a modified genome in an interview with the Associated Press. There is still no confirmation of this information.   Before that, American and Chinese scientists had already conducted experiments on embryos for medical purposes, and after each experiment, the embryos were destroyed. However, in China, unlike most countries, there is no ban on the genetic editing of viable embryos.   After the scientist’s statement, one of the creators of CRISPR / Cas genome editing, Feng Zhang, called for a complete ban on implanting embryos with the edited genome into the mother’s body.   Meanwhile, in the States the other day, the first interim results of clinical trials of the CRISPR-variant CAR-T therapy for the fight against cancer appeared. The University of Pennsylvania Medical Center reported that three patients received injections of edited cells, which took root in their bloodstream and did not cause deterioration. There is no response from patients to therapy yet.  See also: “CRISPR provides an opportunity to save a person from pain” The CAR-T method itself is based on a modification of the genome