Dr. He Jiankui made the announcement in November 2018 at an international conference on gene editing in Hong Kong.
He claimed he had used a gene editing tool, CRISPRCas9, on the embryos of twin baby girls in order to make their offspring resistant to HIV.
Crispr-Cas9 makes it possible to edit genes, the strands of DNA that govern the body, and thus supply a needed gene or disable one that is causing problems.
Dr. He Jiankui studied at Rice and Stanford universities in the United States before returning to China to do research at the Southern University of Science and Technology in Shenzhen.
He said the gene editing occurred during in-vitro fertilization. First, sperm was “washed”
to separate it from semen in which HIV can lurk. A single sperm was placed into a single egg to create an embryo. Then the gene-editing tool was applied.
When the embryos were three to five days old, a few cells were removed and checked for editing. Couples could choose whether to use edited or unedited embryos for pregnancy attempts.
In all, sixteen of twenty-two embryos were edited, and eleven embryos were used in six implant attempts before the twin pregnancy was achieved.
Dr. He Jiankui’s announcement was met with widespread outrage and condemnation. Dr Kiran Musunuru, a gene-editing expert at the University of Pennsylvania called it “unconscionable … an experiment on human beings that is
not morally or ethically defensible”.
Julian Savulescu, a professor of practical ethics at the University of Oxford, said that, if Dr. He Jiankui’s claims were true, the experiment was “monstrous” He pointed out that the embryos had been healthy and there were no known diseases.
“Gene editing itself is experimental and is still associated with off-target mutations, capable of causing genetic problems early and later in life, including the development of cancer.” he added.
Dr Sarah Chan, a bioethicist at the University of Edinburgh, said that, if true, the experiment was “of
grave ethical concern” “The claim made by those responsible for the research is that the babies have been genome edited in an attempt to make them immune to HIV” she said.
“The lifetime risk of contracting HIV is extremely low in the first place; there are other means of prevention and it is no longer an incurable, inevitably terminal disease.
Putting these children at such drastic risk for such a marginal gain is unjustifiable.”
A report last month carried by China’s Xinhua News Agency said Chinese investigators had determined Dr. He Jiankui had acted on his own and would be punished for any violations of the law It said his behavior seriously violated ethics and the integrity of scientific research, was in serious violation of relevant national regulations and created “a pernicious influence at home and abroad” It said the Southern University of Science and Technology would be terminating its contract with Dr He Jiankui.