One side of the argument is that the ethical question has already been breached by the act of conducting this type of research and the time for debate has passed. The next big question to be debated is whether or not the methods are actually close to being able to treat disease.
The paper Protein & Cell, detailing the research, was published on April 18, 2015 in a Chinese journal affiliate of China’s Ministry of Education (1).
In March 2015, rumors had been circulating within the scientific community that the team led by gene-function researcher Junjiu Huang at Sun Yat-sen University in Guangzhou, China had completed gene editing on human embryos. It wasn’t a secret that Huang had requested permission from the Chinese government to begin the gene editing research on non-viable human embryos.
At the center of this controversy is the sense that Huang completely disregarded the “globally widespread policy agreement against altering the human germline.” This alone is considered an unethical act by many in the science community.
Researchers Declare Using CRISPR/Cas9 for Human Embryo Editing Is Premature
Using the CRISPR/Cas9 technique that allows the researcher to slice and replace DNA, the Chinese team edited the non-viable human embryos.
“CRISPR is an RNA-guided platform for gene-editing. It ‘… makes use of a bacterially derived protein (Cas9) and a synthetic guide RNA to introduce a double strand break at a specific location within the genome’. Enzymes are used to target certain DNA sequences. ‘The enzymes cut out the faulty sequence and replace it with a functional copy.’” (2)
The reason scientists had previously vowed to steer clear of gene-editing in humans was because it poses the risk of permanently altering the germline since changes (edits) would be inherited by children who would in turn pass the modified germline to their own children. All future generations would have the edited germline.
The paper details that the scientists edited the hemoglobin-B gene (HBB) (Hemoglobin, Beta – human) (3) in 86 human embryos. These were embryos donated by couples from an in vitro fertilization (IVF) clinic, specifically for research.
The results after two days of the gene-editing molecule injections revealed 54 embryos survived the procedure. Out of those only 4 carried the genetic changes. These changes were designed to (in theory) prevent “beta thalassemia,” which is a blood disorder resulting from a mutated gene.
Also, noted in the paper – the edited embryos had gene mutations besides the HBB and a large number of “off-target effects”, all which could possibly prove harmful.
CRISPR/Csa9 Poor Performer in Human Embryo Gene Editing
Since the CRISPR/Cas9 technique was such a poor performer, the team declared that using it for embryo editing was “premature at this stage.”
The Huang University Ethics Board reviewed the project using international as well as nation ethical standards (4).
The researchers emphasized that they’d only used “abnormal zygotes” (two sperm fertilized embryo) that would normally have been discarded.
The team wrote the reason they used abnormal zygotes was “because ethical concerns preclude studies of gene editing in normal embryos.”
The paper has rekindled the ethical debate over using human embryos in gene editing and set the Internet blazing with rumors of other scientists having also conducted similar research.
References & Image Credits:
(2) TSW: Scientists Call for a Halt to Human Gene Editing
(4) Science Mag