Scientists in China have genetically modified human embryos, embarking on a slippery slope that could be capable of a calamitous ripple effect in human offspring. Scholarship aside, the ethics questions that sprout from genetically altering human embryos are innumerable. In a paper published by the journal Protein and Cell, a research team in GuangZhou, China, headed by Junjiu Huang, detailed their process and results of genetic editing. The gene in question is responsible for β-thalassaemia, which is a blood disorder that can be potentially fatal. Researchers used the CRISPR/Cas9 technique to edit the genes. As a matter of ethics, the researchers only used “non-viable” embryos that would be unable to make it to a live birth.
The Chinese research team started with 86 embryos and only 28 of them were spliced properly. From those 28 embryos, only a portion contained the replacement genes. Huang concedes, “If you want to do it in normal embryos, you need to be close to 100%. That’s why we stopped. We still think it’s too immature.” Yet, he postures that the low efficiency rate could be caused by using “non-viable” embryos, and that the human embryos provide a more accurate representation than animal embryos or adult, human cells.
The genetic experimentation resulted in various “off-target” mutations, which are presumed to be caused by the CRISPR/Cas9 process acting on other areas of the genome. An important point brought up in scientific journal, Nature, is that genetic edits performed on embryos are heritable; therefore, unknown and serious ramifications could unfold upon future generations.
Some fans of the technique believe because genes are edited in the embryonic stage, children could be spared from being born with debilitating genetic disorders. On the whole, any type of genetic research on human embryos that involves replacing genes is regarded as a slippery slope in the scientific community.