In a move that is both groundbreaking and extremely controversial, a group of Chinese scientists released a study detailing their experiments with genetically engineered human embryos. Editing the DNA of humans has long been considered an ethical taboo in the field of science, and the experiments performed by Junjiu Huang and his colleagues at the Sun Yat-sen University in Guangzhou, China have been heavily criticized by both scientists and watchdog groups on the lookout for violations of human ethics.
The report was published in the journal Protein and Cell after being rejected by two other prominent journals, Nature and Science, based on ethical objections. According to the report, the group of Chinese scientists worked primarily with a new technology called CRISPR (clustered regularly interspaced short palindromic repeats), a type of genome editing technique which is rapidly gaining popularity around the world. The team used CRISPR to alter the genes of 86 human embryos, all of which were taken from a local fertility clinic. Trying to eliminate a gene that caused beta-thalassaemia, a deadly blood disorder, the team used CRISPR to cut out the aberrant gene out of the embryos and replace it with a healthy one.
The Telegraph reported on April 23 that Huang has been stamping out fears of eugenics by claiming that the embryos used in the experiments were ‘non-viable’ and could not have matured into children had they been passed to a woman. Nevertheless, the study has come under fire from many critics who believe that editing the genetics of human embryos crosses an ethical line. A group of scientists even went as far as to publish an article in Nature calling for a global moratorium on the practice.
“This news emphasizes the need for an immediate global ban on the creation of GM designer babies,” said Dr. David King, Human Genetics Alert Director, in the Telegraph article. “It is critical that we avoid a eugenic future in which the rich can buy themselves a baby with built-in genetic advantages.”
One of the major concerns with editing the DNA of human embryos is its potentially dangerous effects on generations of people, as any diseases caused by the modification would not only affect one individual, but potentially that individual’s children and grandchildren. The high risk nature of genetic editing in humans is made even more threatening by the fact that most of the technology used for genetic experimentation is in its infancy.
The study itself clearly showed the dangers of genetic modification, with just 71 of the 86 embryos surviving, and only 28 of the surviving embryos being successfully edited. The low success rate was coupled with a host of unintentional and likely undesirable mutations in the DNA of the embryos.
Huang himself recognized that a great deal of work needs to be done before editing human genes can be done safely. “If you want to do it in normal embryos, you need to be close to 100%,” he said in a report by Nature. “That’s why we stopped. We still think it’s too immature.”
While the high number of misfires in Huang’s experiments makes it clear that this type of testing needs to be treated with a great deal of concern for safety, whether experiments with editing the DNA of human embryos should be performed at all is still an ongoing debate.
“What the paper really emphasizes is that we are far away from using genomic editing because it’s not safe. The idea of using this for designer babies is very far-fetched. The technology is too far off,” Dusko Ilic, a stem cell researcher at King’s College, London, told the Guardian. Although Ilic believes the technology is not up to snuff for experiments like this to continue safely, he doesn’t believe they should be halted entirely. “You cannot stop science. No matter what moratorium is proposed, you cannot stop this work continuing around the world.” Additionally, Ilic doesn’t agree with those calling Huang’s study unethical. “These embryos had been fertilized by two sperm. They would have been discarded by any IVF clinic in any country in the world. There is no ethical objection you can bring.”
Other researchers are less willing than Ilic to let the science of human genetic engineering progress unchecked. “No researcher should have the moral warrant to flout the globally widespread policy agreement against modifying the human germ line,” Marcy Darnovsky of the Center for Genetics and Society told NPR. “This paper demonstrates the enormous safety risks that any such attempt would entail, and underlines the urgency of working to forestall other such efforts. The social dangers of creating genetically modified human beings cannot be overstated.”
Darnovsky is not the only one worried about the social implications of the study, George Daley, a stem cell researcher at Harvard, said that “current methods are too inefficient and unsafe” for experiments editing human embryos to continue. “Further, there needs to be careful consideration not only of the safety but also of the social and ethical implications of applying this technology to alter our germ lines,” he said.