In this blog post, we will examine the scientific principles behind three-parent IVF technology for the prevention of genetic diseases, as well as the ethical issues and social implications that arise from it.
On April 6, 2016, in Mexico, the world’s first three-parent baby, Abraham Hassan, was born to two mothers and one father. Normally, a child inherits DNA from the egg and sperm, as well as mitochondrial DNA from the egg, through the process of fertilization, in which the sperm nucleus enters the mother’s egg. However, Shavan, the biological mother of this child, carried a genetic mutation that causes Leigh syndrome, a hereditary neurometabolic disorder that causes gradual deterioration of the central nervous system, including the brain and spinal cord. Due to this genetic mutation in mitochondrial DNA, which accounts for only 0.1% of total DNA, Shaban’s two previous children died at the ages of 8 months and 6 years. She then went to Mexico, where there were no laws regarding genetic engineering, and gave birth to a healthy child through three-parent in vitro fertilization. This method is attracting attention because it can prevent genetic diseases, which have been considered incurable until now. However, while this technology is like a ray of hope for people with mitochondrial genetic diseases who cannot have children, some view it as a precursor to genetic engineering and designer babies. Last year, the UK passed a bill allowing three-parent IVF for the first time in the world. It was decided that the treatment of genetic diseases takes precedence over ethical obligations. It is estimated that 2,500 couples in the UK alone will be able to benefit from this technology. Nevertheless, three-parent IVF is, strictly speaking, a genetic modification technology, and due to the potential for abuse, it remains illegal in some 40 countries. However, it would be premature to judge this technology based on its appearance alone. We will examine the basic principles of three-parent IVF technology, which remains a hot topic in the scientific community with heated debate, and why it is necessary.
Before doing so, it is necessary to first understand mitochondria. Mitochondria are independent and essential cell organelles that are responsible for producing the energy necessary for cellular activity, and the theory of cell symbiosis is widely accepted. They even have their own DNA separate from the DNA in the cell nucleus, and it is said that one in 6,500 women is born with a genetic abnormality in this DNA. These mitochondrial genetic abnormalities mainly cause diseases such as heart disease, Parkinson’s disease, and Huntington’s disease, which are related to cellular energy production, as well as diabetes, hearing impairment, muscular dystrophy, progressive visual impairment, liver dysfunction, and dementia. These diseases can lead to death, or even if the patient survives, they will inevitably suffer from related diseases for the rest of their life. Mitochondrial DNA, which accounts for only 33 of the more than 20,000 DNA strands, is passed on 100% from the mother, and until now, there has been no way to prevent it from causing untold suffering to children. This is where three-parent IVF comes to the rescue. The nucleus is extracted from the egg of a healthy woman and replaced with the nucleus extracted from the mother’s egg, which is then fertilized with the father’s sperm. With this method, a child with healthy mitochondria can be obtained with a simple nucleus replacement. Medical ethicist Dr. Gillian Lockwood’s comments on this procedure, which changes only 0.1% of the total DNA that contributes to energy production, clearly demonstrates its significance. “The three-parent IVF procedure is intended to make a broken biological battery work properly and has nothing to do with a child’s height, eye color, or intelligence. The genes received from the third woman are only 1/1,000 of the DNA, so it should be called 2.0001-parent procedure, not three-parent procedure.”
Among the various criticisms raised by opponents, the most controversial point is that this technology is likely to lead to genetic engineering and designer babies. Three-parent IVF is a small but clear change in DNA, which has great potential for abuse in the future, and if abused, will lead to uncontrollable ethical debates. However, upon closer examination, this procedure is actually quite liberal in comparison to the criticism often levelled at genetic engineering. These perspectives are based on the premise that certain genes are superior to others (known as eugenics), but mitochondria only contribute to the production of energy in cells. It is only possible to replace them with other healthy mitochondria, and there is no intention or possibility of expressing different traits, so it is far from the so-called “designer babies” created by selecting only the traits desired by the parents. All technologies have the potential to be misused, but this technology can be described as free because there is no way to use mitochondrial DNA for other purposes. This can only be part of treatment, and it is not a matter of parents ordering the genes they want at will. We should focus more on the fact that this procedure does not eliminate children with genetic diseases, but only eliminates the disease itself.
Another criticism assumes that children will be born through this procedure. How will children born through this procedure accept the fact that they have other parents? I believe this issue is an exaggeration of the procedure’s name. Although about 0.2% of the DNA comes from another woman, mitochondrial DNA is only responsible for energy production and does not contribute to the formation of organs, so it is unreasonable to consider her a parent. The child will look just like their parents and will be no different from other children, so social acceptance will play an important role. In addition, in relation to this, the bioethics community takes the position that, in consideration of the child’s right to know, the fact that the child has undergone assisted reproductive technology should be kept secret until the child reaches adulthood, at which point it should be disclosed. In addition to this method, if professional counselors are assigned to provide ongoing support after the child reaches adulthood, it will be of great help in resolving any psychological problems that may arise. No parent wants their child to be born with a disease. If the earnest wishes of parents are conveyed to their children and supported by institutional assistance at the national level, this issue can undoubtedly be resolved.
In fact, the most important issue regarding this technology is its safety. Of course, the American newsweekly Time reported that researchers examined the three children born this time, the genetic disease of Abraham Hassan, and the possibility of Lee syndrome, and confirmed that the possibility of mitochondrial DNA mutation is less than 1%. However, it is not always safe and successful. In fact, when extracting the nucleus from an egg, it is extracted by squeezing, and at this time, a small amount of the mother’s mitochondria is mixed in. When that nucleus is injected into another egg, the mitochondrial DNA from the two maternal lines compete within the egg, and the outcome of that competition varies from case to case. Due to this uncertainty, the British government legalized mitochondrial replacement therapy last year, but the relevant authorities in the UK have not yet approved its clinical use. Legislation enables the start of the approval process, but the procedure can only be performed when there is clear scientific evidence that there is little risk. In the US, a committee led by the National Academy of Sciences, Engineering, and Medicine recommended this year that “clinical trials should not be allowed unless safety is confirmed through preclinical data.” It is true that we all need to approach this issue with caution and prudence. However, this is only the initial stage that all technologies go through. We have sufficiently confirmed the usefulness of this in vitro fertilization method, and we are now in the process of verifying its risks. What is needed in this process is proper legislation and regulation. We must actively encourage the wise management of this diamond in the rough so that it can be transformed into a beautiful jewel.
As such, three-parent technology is different from existing genetic engineering technology and must be utilized. Of course, it is not yet perfect in theory, but it is clear that it must be achieved over time, and research proving its safety is being conducted and published in other countries. However, Article 21, Paragraph 2, Item 4 of the Act on Bioethics and Safety in Korea prohibits human genetic modification. Under current law, not only is the procedure not yet available, but even research related to it is not allowed, and there is no discussion on the matter. Parents desperate to save their baby’s life will eventually go to a country where there are no regulations to undergo three-parent IVF. We must hold a democratic debate on this technology and ensure that it is carried out under a system of scientific oversight and transparent disclosure. Scientific progress has always begun with new challenges. In the case of fatal diseases for which there is no adequate treatment, conducting research for therapeutic purposes is both a new challenge and a new hope. We have no reason to refuse discussion under the pretext of ethics. We earnestly dream of the day when three-parent children will become a normal part of our society, without prejudice and without being labeled as “three-parent children.”
