Chinese scientists continue to defy ethics by editing human embryos

In April of 2015, Chinese researchers revealed to the world that they had modified the HBB gene in human preimplantation embryos using the new genome-editing technology CRISPR/Cas9, which has been linked to the disease thalassemia. The news ignited a media frenzy, prompting scientists from all over the world to debate the ethics of such research, eventually leading to the adoption of an international ban on the use of CRISPR with human embryos.

Now, researchers from Guangzhou Medical University have used the CRISPR/Cas9 method to alter human embryos once more. The procedure was used on unviable embryos with extra chromosomes, according to the researchers. Furthermore, the researchers collected 213 fertilized eggs from a fertility clinic that had been deemed "unsuitable" for in vitro fertilization due to an extra collection of chromosomes. Every egg was used by the Guangzhou team on the condition that they will not be allowed to turn into human beings.

The researchers wanted to add a mutation to the immune cell gene CCR5, which has previously been connected to natural HIV resistance. The researcher hoped to learn more about the possibility of creating HIV-resistant fetuses.

Just 4 out of 26 embryos were successfully edited, according to the researchers, with many still bearing genes that had not been changed and others resulting in off-target gene mutations. After three days, all of the embryos were killed, according to the researchers.

This study's results were recently published in the Journal of Assisted Reproduction and Genetics in an article titled “Introducing Precise Genetic Modifications into Human 3PN Embryos by CRISPR/Cas-Mediated Genome Editing.”

“This paper appears to provide nothing more than anecdotal proof that it operates in human embryos,” said George Daley, M.D., Ph.D., director of the stem cell transplantation program at Boston Children's Hospital and Dana-Farber Cancer Institute, to Nature News. “We're quite a long way from reaching our full potential.”

Even in the middle of the debate, there might be some valuable knowledge to be gleaned for the research community.

“The good news is that the methodology worked for this group in the same way it did for the first group,” Peter Donovan, Ph.D., a professor at the University of California, Irvine, told The Verge. “This demonstrates the science's replicability... However, this group of researchers also confirmed what the first group had discovered, namely, that this form of gene editing has off-target effects.”

The Chinese scientists seem unfazed by their peers' criticism of their work, claiming that the research they're doing is revolutionary and will pave the way for future studies and inventions while emphasizing that no genetically modified embryos will be allowed to mature. Only time will say if their analysis yields any useful results or is unanimously condemned as unethical.