Last month, scientists from the Sun Yat-sen University in Guangzhou published the first report of genetically engineering (inviable) human embryos using CRISPR/Cas9 (see our article “Breakthrough in Breaking DNA” for a primer on the technology). Technologically speaking, this paper is pretty boring. CRISPR/Cas9 has been used in organisms up and down the tree of life. The only thing that sets it apart is the type of cell they use, human embryos. Us.
Prior to this report’s publication, prominent biologists had already penned letters in Science and Nature calling on the global scientific community to stop all human germline use of CRISPR/Cas9 until we can resolve its shortcomings. The NIH agreed and said they would not fund this sort of research. There are two main arguments as to why some want a moratorium on human gene editing:
- The technology is powerful, but too dangerous at the moment. The original report’s scientists agree that thorough research is “sorely needed” before birthing any edited babies.
- Editing the human genome creates ethical dilemmas that we haven’t sufficiently addressed.
It’s only a matter of time before this technology is ironed out. Combining genes from different organisms, for example, was once a hotly debated technology like CRISPR/Cas9, but is now a staple in undergraduate biology courses. But before human gene editing is close to being perfected, we need to figure out when it would be acceptable, if at all, for us to use it in embryos that will eventually become full-fledged human beings.
According to a 2014 survey, 50% of people find genetically modified babies acceptable if it’s done to “reduce the risk of serious diseases.” However, that number drops to only 15% if it’s done to make the baby more intelligent. In 2004 (before CRISPR/Cas9), 61% of Americans were in favor of selectively choosing embryos that are free of genetic diseases. This technology can also be used to selectively choose the sex of a child. When asked if “social sex selection” were acceptable, 57% said no.
Saving a child from a life of a known genetic disease seems reasonably acceptable. But genetically imposing our idea of what is good for them is deeply unsettling. The former brings a child’s quality of life back to the human average, saving them from chronic suffering or an unnecessarily short life. The latter takes the express train straight to how we define nature and ourselves as humans.
Raising a child requires a balance between accepting love and transforming love. Accepting love is when parents accept their children for who they are. Transforming love tries to ensure the well-being of children by nurturing and improving them. Together, these two types of love promote healthy parent-child relationships. When transforming love takes over too strongly, we get tiger moms and helicopter parents.
David Baltimore. One of the leading scientists calling for a moratorium on human germline gene editing. Photo: Wikipedia
One fear of genetic engineering is that it is the extreme case of transforming love. Overzealous parents would impose irreversible traits on their child at the most basic level, subverting her autonomy as a human being. Conversely, a child of a tiger mom may have her social identity heavily molded during her childhood, but would still have an opportunity, however small, to rebel, flee, or choose her own path.
However, some argue that children don’t have autonomy in choosing their genomes anyway. Parents already have enormous sway in what kind of children they have. They have already made a choice about their mate, either consciously or not, to increase their child’s odds in the genetic lottery. Sperm donation recipients can screen for physical characteristics and education level of their child's father. And it's legal to choose the sex of your child through a couple of different methods.
According to NYU philosopher S. Matthew Liao, there is an important distinction to make. Choosing a mate, sperm donor, or child’s sex using today’s established technology is a matter of selection. CRISPR/Cas9 differs in that it modifies an embryo. A child born of sperm or embryo selection cannot argue that the selection changed who they would have been for the worse. They would not have existed if their parents chose differently. Conversely, a child born of a genetic modification could argue that their human identity has been harmed because of the choice their parents made to engineer their genome in an irreversible way.
This is only the tip of the ethical iceberg that awaits us. Modifying human genomes before birth directly questions what it means to be a human being (as opposed to just animals roaming about). CRISPR/Cas9 is here to stay and will inevitably become ingrained in human society. An anonymous source has told Nature that other groups are already pursuing human embryo editing. (It is already deeply established in biomedical research after just 3 years). Many of us would agree that once the technology is optimized, it would be an extremely powerful tool to thwart suffering and pain stemming from genetic diseases. But we need to start thoroughly discussing the ethical limitations we place on CRISPR/Cas9 before we simply let fear of the unknown suffocate one of the greatest innovations of our century.
