In this blog post, we take an in-depth look at whether gene editing technology could be a breakthrough in disease treatment or an ethical dilemma that threatens human dignity and social justice.
Starting with Mendel’s laws of inheritance, genetics has developed into a field of study called “genetic engineering,” which involves directly manipulating and processing genes. Genetic information in living organisms is stored in DNA in the form of base sequences, and proteins are created based on these base sequences, which then combine to form a living organism. The information stored in DNA is an important factor that determines the characteristics and functions of living organisms and is the source of the diverse characteristics of different organisms. Therefore, if we can read this base sequence and identify the proteins expressed by a specific sequence and the diseases or disorders caused by those proteins, we will be able to find only those parts and make slight “modifications” to prevent the onset of disease. This technology can be applied not only to genetic diseases but also to complex diseases such as cancer, and is expected to greatly expand the possibilities of personalized medicine. Scientists began to search for ways to “modify” genes.
In 1970, restriction enzymes, or “gene scissors” that recognize specific sequences of DNA and cut only those parts, were discovered, leading to the birth of genetic recombination technology. Genetic engineering using restriction enzymes is not a technology that allows genes to be freely “edited,” but rather a technology that simply inserts the desired base sequence from another DNA, and is therefore called genetic recombination technology. Genetic recombination technology was initially limited to relatively simple organisms, but over time it has become applicable to increasingly complex organisms. However, restriction enzymes can only recognize base sequences of less than 10 bases, limiting their use to plasmids (ring-shaped DNA found in bacterial cells) of fungi, which have short base sequences.
In 2012, CRISPR, a powerful gene editing tool that overcomes these limitations, was developed. CRISPR is a gene found in the DNA of bacteria that is responsible for the immune system against bacteriophages, which are viruses that attack bacteria. Bacteriophages insert their DNA into bacteria, use the bacteria’s nucleus to replicate themselves, and then burst the bacteria, killing them. Bacteria have developed their own unique immune system to counter this. When a bacteriophage inserts its DNA into a bacterium, the bacterium uses a protein called Cas9 to insert a part of this DNA into its CRISPR, which can then be passed on to the next generation. When that bacterium or its offspring is attacked again by bacteriophages, the bacterium transcribes the gene inserted into CRISPR to create gRNA that searches for the phage DNA. This forms a complex with the Cas9 protein, and the gRNA in the complex finds and binds to the bacterium’s DNA, and then the Cas9 protein cuts the bacterium’s DNA.
Humans have taken notice of this system. If we attach RNA that can bind complementarily to the sequence of the gene we want to cut to the Cas9 protein, the complex will be able to effectively cut the specific part of the DNA we want. In addition, CRISPR gene scissors are simpler in structure than existing restriction enzymes and other gene scissors, and are easy to use because only the RNA needs to be changed according to the desired target. CRISPR technology is currently being actively researched at the forefront of genetic engineering, and the ability to easily cut the desired parts of genes has accelerated the development of gene editing technology.
If this gene editing technology is developed and improved, it will be possible to treat genetic diseases caused by genetic defects by directly manipulating the patient’s DNA in the future. In addition, gene editing technology has the potential to be used as a fundamental treatment for rare and chronic diseases. The development of gene editing technology is opening up the possibility of overcoming diseases that are currently untreatable or extremely difficult to treat. But what if we go even further and manipulate genes at the fertilized egg stage before human development? The emergence of “designer baby” technology, which allows genes to be manipulated as desired, will cause considerable social controversy. In fact, “designer baby” technology is already in commercial use. This technology is called preimplantation genetic diagnosis (PGD), which enables people with genetic diseases to have normal children. This technology, which involves in vitro fertilization using a test tube and then selecting genetically normal embryos from among the fertilized embryos for implantation into the uterus, is strictly speaking not “designer babies” but rather “selective babies” that are genetically free of defects. Gene editing technology directly modifies these embryos to fundamentally improve not only the health but also the abilities of the children who are born.
In China, where genetic manipulation of embryos is not currently prohibited, research results on this technology are gradually being released. Recently, researchers at Guangzhou University in China announced that they had successfully manipulated genes related to HIV infection in human fertilized eggs using this technology. However, this is still limited to slight modifications of the few genes that we know of. Freely removing and inserting genes to obtain the abilities and traits we desire is still a distant dream. But will the era of “customized babies” made possible by free gene editing technology at the fertilized egg stage ever arrive?
First, let’s consider the process of technological development that would lead to such an era. Biotechnology, which targets living organisms, develops through numerous clinical trials to mitigate potential risks and side effects. However, such clinical trials, especially those involving the manipulation of human genes, are extremely dangerous as they could take a life if something goes wrong. Even if we leave it up to the individual to decide whether to participate in clinical trials using gene editing technology as a last resort for genetic diseases, especially incurable diseases, what about clinical trials of custom baby technology that manipulates the genes of fertilized eggs? The fertilized eggs used in the experiments would be exposed to enormous risks regardless of their own will, and if the fertilized eggs were to die or give birth to deformed babies due to serious errors or side effects during the experiments, it would not be acceptable as a “sacrifice for the advancement of humanity.” The fact that technological advancement through experiments can greatly benefit humanity does not justify the unethical nature of the experimental process.
Let us assume that the development of fertilized egg gene editing technology has been accompanied by the development of other biotechnologies and careful prior review to minimize the sacrifices mentioned above. We now live in a world where anyone can freely create a customized baby as long as they are willing to pay the cost. Would such technology be a blessing for humanity? Let’s consider this from the perspective of the child, not the parents. Children would be designed according to their parents’ desires, regardless of their own will, and would become mere means of satisfying their parents’ desires. This could easily lead to conflict between parents and children. This is not the only source of conflict. Some parents may be opposed to this technology for ethical or religious reasons. Their naturally born children will inevitably have lower physical abilities than customized babies born through gene editing technology. These children, who will experience a difference in abilities that cannot be overcome even with the same amount of effort, may resent their parents for neglecting them.
Let’s expand this to a societal issue. In a society where custom-made babies are commonplace, there will be a huge gap between those who have benefited from the technology and those who have not. Relatively wealthy parents will spend large sums of money to give their children superior abilities, and these children will have a head start over those born to parents who cannot afford to do so. Social mobility through fair competition will disappear, and polarization will become even more severe.
In that case, how about imposing partial controls on gene editing technology? Manipulation to develop physical appearance and abilities should be strictly controlled and only allowed for the purpose of preventing congenital genetic diseases, intractable diseases, and incurable diseases. This logic of regulating the enhancement of abilities and allowing only treatments for health purposes raises the question of where to draw the line between ability and health. Suppose that a fertilized egg test shows that a child has a high probability of developing alopecia. Alopecia is a typical genetic disease that is inherited from the father, but it is also a factor that reduces physical appearance, which is an external ability. What if the test shows that the child has a high probability of developing ADHD, a congenital attention deficit disorder? Treatment for ADHD can improve health as well as external abilities such as attention span. Is the congenital treatment of such diseases a promotion of health or an enhancement of abilities? “Health” and “external abilities” are ultimately different aspects of the same thing. Therefore, partial control of gene editing technology will constantly raise the debate of how much is health promotion and how much is ability enhancement.
Such partial control can also cause other problems. Once the technology exists, partial control cannot prevent the formation of a black market. There will be many parents who want to use gene editing technology to give their children only good abilities. Among the privileged classes with wealth and power, there will be those who are willing to pay enormous sums of money to secretly benefit from such technology. Goods and services for which there is strong demand will not disappear simply because they are prohibited by law; they will only give rise to black markets. Gene editing technology used illegally on fertilized eggs will not be safe, and consumers will not be compensated for any harm they may suffer.
Gene editing technology will undoubtedly have a huge impact on human life. However, gene editing technology for fertilized eggs must be controlled from an ethical and social justice perspective. Furthermore, as mentioned above, partial control of gene editing technology for fertilized eggs is ineffective. In other words, complete control is desirable. Instead, various fields in which gene editing technology can be utilized should be explored and applied. For example, it could be used to repair the immune cells of people with incurable diseases, rather than manipulating fertilized eggs. In addition, ways to expand the scope of application to general animals and plants should be explored, such as using gene editing to develop crops that are resistant to pests and diseases and have good taste and nutritional value.
Furthermore, in-depth discussions are needed on the ethical issues and policy aspects of gene editing technology. It is essential to analyze the impact of gene editing technology on society and establish appropriate regulations and legal frameworks based on this analysis. This will be an important process that goes beyond the advancement of science and technology and shapes the future of humanity. How will humans use the power of this new technology? Whether gene editing technology will become a tool for human development and a better life, or whether it will lead to new forms of inequality and ethical dilemmas, depends on how we handle this technology and where we set its limits.
