In November 2020 ) broke the news that the Chinese biophysicist He Jiankui had done genetic editing on human embryos with the CRISPR technique (pronounced “crisper”). The technique is based on a molecular system of defense of some bacteria against the invasion of viruses that allows cutting and pasting with unprecedented precision any type of DNA, including human. The scientist had implanted two genetically modified human embryos in the uterus of a pregnant woman, and a third in another pregnant woman. Two twin girls were already born. The following year, the third child was born, and a Chinese court sentenced He Jiankui to three years in prison. He was released this month.
The scientist’s actions have drawn international condemnation. The sentencing court said he “deliberately violated” China’s medical standards and that he “unscrupulously applied gene-editing technology in assisted human reproduction medicine.” According to the magazine MIT Technology Review, which revealed the CRISPR babies project, He Jiankui answered the phone earlier this month, but stated that “it is not convenient to talk about it at the moment”. The scientist is described by acquaintances as “idealistic, naive and ambitious”. He studied at the American universities of Rice and Stanford. After the MIT website leaked in November 2018, He took to YouTube to announce the birth of the twins. “Nana e Lulu” in English.
The experiments on human embryos that led to the three Genetically modified children were made at the Southern University of Science and Technology in Shenzhen City. The intention was to introduce a mutation in the CCR5 gene into the embryos, which encodes a protein on the surface of defense cells that HIV uses in its infection. The twins’ father is HIV positive. About 10% of northern Europeans carry a natural mutation in the gene called delta-32, which confers resistance to some strains of HIV in homozygotes (with copies of the mutation on both chromosomes), and more latency in the progression of AIDS in heterozygotes (with a single copy of the mutation ).
He may not have been able to reproduce the delta-16 perfectly, accidentally causing possible mutations with others unknown functional effects. He also may not have been able to change all copies of CCR5 in girls, who are either genetic mosaics for the artificial mutation (ie, carry it in some tissues of the body but not others) or heterozygotes for it. Information about the three children, however, is still scarce.
For geneticist Fyodor Urnov, who studies genome editing with CRISPR at the University of California at Berkeley, there are no circumstances that justify genetic modification of human embryos, but he supports editing after birth to alleviate some rare genetic diseases. Urnov isn’t the only one who thinks it’s acceptable to use genetic engineering to rid children of congenital genetic diseases.
A Pew Research Center survey showed that the majority of the population in 10 Countries support this specific use of the technology: 20154926 % agree globally, with a maximum of 8010894115001 % in Spain and a less expressive majority of 57% in Japan. In Brazil, 57% approve of this use. However, when the question was whether gene editing would be acceptable to make the baby smarter, a majority of approval was obtained only in India (28%). 70% of respondents globally disapprove of this use, among them 32% of Brazilians. Among the three countries of the Americas included, however (USA, Canada and Brazil), the 27% of Brazilians who approve of increasing intelligence through genetic engineering are the most expressive group with this opinion. The survey is from December 2020.
In addition to possibly failing in his goals when editing the embryos, He Jiankui also took shortcuts in ethical procedures. It did not justify the need for this genetic editing in the embryos of these girls. They have an HIV positive father but are out of risk of contracting HIV from him. Today, antiretroviral drugs allow a practically normal life for seropositive people. Those with an undetectable viral load are less likely to transmit the virus than people who do not know their infection status because of a lack of routine testing. Therefore, from a moral and medical point of view, the intervention was unnecessary.
The consent form for parents to sign was created by He Jiankui himself and does not follow the required standards. In addition, it looks more like a business contract, in which there is greater concern with the profits from the children’s image rights than with their health.
Published, concomitantly with the experiment and together with a public relations professional, a bioethics article on gene editing. In the article, He gives advice that he himself violated with this experiment.
Problems with the technique
Proposals to globally regulate human research like He’s are stalled, especially after the pandemic, which took the spotlight off the issue. The very origin of the new coronavirus also raises questions about the effectiveness of the regulation of medical research.While he was in prison, it was discovered that the CRISPR technique can remove entire chromosomes from embryos treated with it, something very worrying and that can result in severe deficiencies. Other teams working on human genome editing around the world believe that the technology has not advanced to the point of starting clinical applications at this time.
Also, CRISPR scissors don’t look as sharp as you thought, they can cut DNA in the wrong place and introduce mutations. A study published in the journal PNAS indicated that 16% of human embryos treated with the technique had this problem. The new technology remains a hope for genetic ailments such as cystic fibrosis, Tay-Sachs and Huntington’s diseases (which lead to neurodegeneration in children and adults, respectively, causing premature death), among others.