CRISPR-Cas9: How far will ethical transgressions go?

A team in China has just published the results of their research using the CRISPR-Cas9 technique in viable human embryos. The experiments were carried out during the zygote stage of embryonic development, meaning the phase with the first cell following fertilization.  

These embryos were specifically created from ovocytes donated for research from fertility clinics. Each ovocyte was then fertilized by injecting sperm from one of two men with a hereditary disease.

The CRISPR-Cas9 gene editing technique was then used on these single-cell embryos before they started dividing, in an attempt to “correct” the embryos’ DNA at the zygote stage, targeting the genes responsible for the disease.

One of the men is a carrier for a genetic mutation on his X chromosome (called G1376T for the gene making an enzyme called glucose-6-phosphate dehydrogenase (G6PD enzyme), which plays a critical role for red blood cells.

The absence of this enzyme results in a disorder whereby eating certain food such as fava beans can trigger the destruction of red blood cells thereby the name favism.

The Chinese team demonstrated that in two of the resulting embryos from IVF, the CRISPR-Cas9 tool corrected the G1376T mutation. But in one of the embryos, not all the cells were corrected. Thus CRISPR “turned off” the G6PD gene in some of its cells, but not all of them, so that rather than fixing it, it made what is known as a “mosaic”.

The second sperm donor had a mutation called beta 41-42, which is one of the causes of the blood disease beta-thalassemia. Four of the resulting embryos from the IVF carried this mutation. In one, the CRISPR-Cas9 technique induced another mutation elsewhere in the DNA. In another embryo, the mutation was successfully repaired in only some of the cells, thereby creating another “mosaic” embryo. The CRISPR-Cas9 technique did not function in the other two embryos.

In March 2015, and again one year later, in 2016, a Chinese team had already caused quite an international uproar with theses new ethical issues. At the time, the researchers used abnormal human embryos generally believed to be non-viable. In the case herewith reported, this is the first time in history that a research team has published the results of their experiments on human embryos, performed on viable, fertilized embryos uniquely for research purposes.

The results from Jianquio Liu’s lab however, demonstrate that the technology is far from being considered efficacious and safe. There were reports of “mosaicism” as well as mutations, meaning that CRISPR-Cas9 introduces “errors” somewhere else in the genome.

The study published in Molecular Genetics and Genomics is alarming and should arouse a consensus of righteous indignation internationally, since a new boundary in unethical behavior has now been crossed.

Alliance VITA’s position

“This recent publication raises serious concerns. As with the results published with children born from the 3-parent IVF technique, we are confronted with a ‘fait-accompli’ on an international level. We must keep in mind that China, already considered laxest, is basically a country whose laws and mentality are ultra-eugenic. Nevertheless, the experiments performed on human embryos affect all humanity. Currently, we can’t imagine implanting human embryos in a uterus to give birth to genetically-modified children using these rudimentary genetic engineering techniques, but how can some countries be stopped from going to this extreme?

Recently in the Ukraine and Mexico, there were cases of children born from the 3-parent-IVF technique, proving that even more ethically scandalous experiments like this one, may be looming on the horizon. The international community should form a consensus to request a moratorium and thereby condemn such an infringement on human rights.”

Alliance VITA’s campaign STOP GM Babies was launched as a service for public awareness regarding these risks and to oppose this dangerous tendency of genetically modifying reproductive cells and human embryos.


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