In November of 2018, a chinese researcher named He Jiankui brought the first genetically edited human embryos to life. These twins, Nana and Lulu, will surely occupy the scientific spotlight in the years to come, as they represent society’s first case of the biological and ethical viability of genetic editing in human embryos. Jiankui edited the genomes of the twins to eliminate the possibility of contracting HIV from their father, who was infected with this unfortunate disease. With the heavy prevalence of anti-HIV stigma in China, Jiankui felt compelled to take action so that the twins would not have to endure the same physical and psychological consequences as do others infected with HIV.
The practice of gene editing in humans is not novel in our society. We currently use somatic gene therapies that involve the editing of stem cells to fix genetic mutations so that the stem cells can produce healthy hemoglobin, rather than faulty blood cells. However, Jiankui used germline editing on the twins. This practice is vastly different because germline editing entails a genetic change that can be passed onto future generations, whereas somatic gene therapy only affects the patient being treated. Jiankui did this by using CRISPR/CAS 9 techniques to edit out the CCR5 gene that is necessary for HIV to affect human blood cells.
If we ignore the fact that Jiankui proceeded without any oversight from the international scientific community, his actions seem morally permissible in that they are projected to remove a lot of medical and psychological suffering for the twins. However, this is hardly the case. Though CRISPR/CAS9 is a rather precise and effective technique, its use has never been shown to be perfect in application. Specifically, there is the concern of producing off-target effects (other undesired mutations in the genome) during the practice of germline editing. By removing the twins’ susceptibility to HIV, Jiankui has also increased their probability of contracting influenza and West Nile Virus. This is more ethically problematic, as it remains unclear how the rest of the twins' genomes were affected in the process.
Besides the problem of off-target effects, there is further moral controversy due to the beneficial implications of editing the CCR5 gene. Though studies have shown that removal of the CCR5 gene will render the HIV infection unable to affect human blood cells, other studies performed in mice have revealed that the removal of this gene is also linked with a marked increase in memory and brain functionality. This now raises the problem of whether this genetic editing qualifies as a treatment to remove HIV or as an enhancement of the twins’ mental and cognitive abilities. If the line between treatment and enhancement cannot be established, this sets a precedent for endless genetic editing in the name of medical benefit.
Despite these ethical problems, the bottom line remains that Jiankui has reduced immense suffering for these twins by removing their susceptibility to HIV. Does this outweigh some of the other ethical considerations of germline editing? Nonetheless, it is clear that we should address this issue proactively as a society, rather than reactively dealing with the ramifications of germline editing.
Sources:
https://www.medicalnewstoday.com/articles/319817.php
https://www.sciencemag.org/news/2018/11/crispr-bombshell-chinese-researcher-claims-have-created-gene-edited-twins
https://www.sciencenews.org/article/gene-edited-babies-top-science-stories-2018-yir
https://news.harvard.edu/gazette/story/2019/01/perspectives-on-gene-editing/
https://www.technologyreview.com/s/612997/the-crispr-twins-had-their-brains-altered/