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 treat the disease before it develops. 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 searching for ways to “modify” genes.
In 1970, restriction enzymes, or “gene scissors,” were discovered that recognize specific sequences of DNA and cut only those parts, giving rise to genetic recombination technology. Genetic engineering using restriction enzymes is not the free “editing” of genes, but rather the simple insertion of desired base sequences from other DNA, which is why it is called genetic recombination technology. Genetic recombination technology was initially limited to relatively simple organisms, but over time, it became 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 bacterial cell, 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 took 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 refined, it will be possible to treat genetic diseases caused by genetic defects by directly modifying 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. Diseases that are currently untreatable or have extremely limited treatment options may be overcome with the advancement of gene editing technology. But what if we go even further and manipulate genes at the fertilized egg stage before they develop into humans? 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, called preimplantation genetic diagnosis (PGD), allows people with genetic disorders 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,” which are embryos selected for the absence of genetic defects. Gene editing technology directly modifies these embryos to fundamentally improve not only the health but also the abilities of the children who will be 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 minor modifications of the few genes that we currently know about. The ability to freely remove and insert genes to obtain the abilities and traits we desire is still a long way off. But will the era of “designer 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 make such an era possible. Biotechnology, which deals with living organisms, develops through numerous clinical trials to mitigate potential risks and side effects. However, clinical trials, especially those involving the manipulation of human genes, which are fundamental to human life, are extremely dangerous because they can 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 customized baby technology that manipulates the genes of fertilized eggs? The fertilized eggs used in the experiments must take enormous risks regardless of their own will, and if the fertilized eggs die or deformed babies are born due to serious errors or side effects during the experiments, it cannot be tolerated under the name of “sacrifice for the advancement of humanity.” The fact that technological advancement through experiments will greatly benefit humanity cannot 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 would live in a world where anyone could freely create a customized baby as long as they could pay for it. Would such technology really be a blessing for humanity? Let’s consider this from the perspective of the child, not the parents. The child would be designed according to the desires of the parents, regardless of their own will, and would become a means of satisfying the parents’ desires. This could easily lead to conflict between parents and children. This is not the only cause 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 custom-made babies born through gene editing technology. Even if they make the same effort, these children may feel resentful toward their parents for neglecting them because of their perceived differences in ability.
Let’s expand this to a societal issue. In a society where customized 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.
So, how about imposing partial controls on gene editing technology? Manipulation to develop physical appearance or abilities would be strictly controlled and only allowed for the purpose of preventing congenital genetic diseases, intractable diseases, and terminal illnesses. 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 continue to spark debate over where the line between health promotion and ability enhancement lies.
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 desirable abilities. In particular, among the privileged classes with wealth and power, there will be those who are willing to pay enormous costs to secretly benefit from such technology. Goods and services with strong demand will not disappear just because they are prohibited by law; they will only create a black market. Illegally performed gene editing technology on fertilized eggs will not be guaranteed to be safe, and consumers will not be compensated for any damage that may occur.
Gene editing technology will undoubtedly have a huge impact on human life. However, gene editing technology on 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, rather than manipulating fertilized eggs, it could be used to repair the immune cells of people with incurable diseases. In addition, we should explore ways to expand the use of gene editing to animals and plants, such as developing crops that are resistant to pests and diseases and have good taste and nutritional value.
Furthermore, in addition to ethical issues, in-depth discussions on the policy aspects of gene editing technology are necessary. 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 the advancement of humanity 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.
