In this blog post, we examine whether gene editing technology is progress for a healthy future for humanity or a dangerous attempt to break ethical boundaries.
In April 2019, Chinese researchers attempted to genetically modify human embryos using gene editing technology for the first time in the world. This case, in which the beta-thalassemia gene Hemoglobin-B was edited using embryos that were unable to be born normally, caused a huge controversy around the world. Seventeen prominent scientists, including Nobel Prize winner David Baltimore, published an editorial in Science stating that “scientists should refrain from attempting to modify the genome of human embryos.” On the other hand, Dr. George Daley of Harvard Medical School stated that he “defends the fundamental scientific value of human embryo gene editing research,” and many scientists agreed with this position. Gene editing technology is expected to be used to treat genetic diseases, and through continuous research, the technology is rapidly advancing, so safety issues are expected to be resolved in the near future. Nevertheless, many scientists oppose this technology because of the possibility that genes could be modified for non-therapeutic purposes. In other words, they are concerned about the possibility of violating human dignity.
Gene editing can be applied to both germ cell modification and somatic cell modification. Let us examine the scope of gene editing in each of these two cases. Currently, most countries around the world, including Korea, prohibit germ cell gene modification for medical purposes based on ethical considerations, except in special cases. Consider the case of purchasing a custom-built computer. People choose the specifications, such as the CPU and memory, and build the computer with the combination they like best. If germ cell modification is permitted and human embryo gene editing is abused, the target will change from computers to humans. Factors such as a child’s skin color, height, and intelligence will become the result of parental preferences, which means the birth of “customized babies.” This process could raise questions about human dignity. Edward Lanphier, president of the Alliance for Regenerative Medicine, and his colleagues warned in Nature that “modifying human embryos could be misused for non-therapeutic purposes,” arguing that “we are not genetically modified mice. Modifying human germ cells is fundamentally unethical.”
Furthermore, gene editing violates the fundamental principle of nature, which is genetic diversity. When a species becomes extinct in an ecosystem, the balance is destroyed and chaos can ensue. To prevent this, all living things produce a variety of genes to survive even in unexpected situations. However, if gene editing of embryos is allowed, parents will edit their children’s genes, and most people prefer similar traits. As a result, the genetic diversity of babies will inevitably decrease.
Nevertheless, the loss in terms of disease treatment is too great to abandon germ cell gene editing on the grounds of human dignity and genetic diversity. Nobel Prize winner and geneticist Craig Mello said, “I believe that in the distant future, we will be able to prevent cancer, diabetes, and other age-related diseases through germ cell modification.” In fact, thousands of human diseases are associated with changes in specific genes, so gene editing at the embryonic stage is very significant for disease treatment. In response, Lanphier proposed an alternative solution: using existing technology to select embryos before they are implanted in the womb, thereby eliminating the cause of disease without modifying germ cells. However, Harvard Medical School geneticist George Church countered that “with advances in life sciences, the number of genes involved in a single disease is increasing. According to Lanphier’s logic, most embryos would have to be discarded. Gene editing technology increases the likelihood of obtaining healthy embryos.”
Very few people would argue against the important role that germline gene therapy plays in the treatment of genetic diseases. It would be foolish to completely ban germline gene editing on ethical grounds. Rather, in a situation where disease treatment is possible through gene editing, it may be ethically problematic to leave the disease untreated. Therefore, it is necessary to enact laws that allow germline gene editing for therapeutic purposes but strictly prohibit non-therapeutic genetic modification. In this way, germline gene editing can become a technology that satisfies ethical standards and is of great benefit to humanity.
There is great concern that the results of embryo gene editing could be passed on to future generations. On the other hand, somatic cell modification does not pose genetic problems and is not considered a serious technology. Gene editing technology is currently being used for somatic cell modification, and one biotechnology company is using gene editing technology to remove the genes necessary for the human immunodeficiency virus to invade cells. Somatic cell modification does not raise issues of human dignity or genetic diversity. Somatic cell modification does not undermine the irreplaceable value of each individual human being. In terms of genetic diversity, somatic cell modification does not affect future generations and therefore does not harm genetic diversity.
The problem with somatic cell gene editing is that wealthy people may change their inferior traits into superior ones through non-therapeutic genetic modification, while poor people will be forced to maintain their inferior traits due to economic difficulties, which could widen the gap between the rich and the poor. However, this is not a sufficient reason to ban somatic cell modification. Gene editing is similar to plastic surgery, which is more common among people with greater financial means, but there are no legal restrictions on it. Similarly, there is no right to prevent people from paying for gene editing using ethical technologies as long as it is done in a legitimate manner. Therefore, somatic cell gene modification should be free from legal restrictions, whether for therapeutic or non-therapeutic purposes.
If somatic cell gene editing does not pose ethical problems, why is germ cell modification necessary? Somatic cell modification technology has difficulty targeting defective genes. On the other hand, at the embryonic stage, only a small number of cells exist, which increases the possibility of treatment. Therefore, many scientists support embryo gene editing but argue that sufficient discussion is necessary from an ethical perspective.
So far, we have looked at the scope of acceptability for germ cell and somatic cell gene editing. Because somatic cell modification and germ cell modification through gene editing are different, different legal standards need to be applied. Edward Lanphier of the Alliance for Regenerative Medicine and four co-authors, all life scientists, stated in Nature that “a clear distinction must be made between gene editing of somatic cells and germ cells.” As many scientists are calling for legal revisions to allow gene editing research, we hope that relevant laws will be revised as soon as possible so that people can reap the benefits of gene editing.
