If “modification” is defined as any intervention or change in the genetic material contained in a cell, even the act of transferring it from one place to another without changing its DNA sequence would be an act of modification, according to the Convention. But, since “modification” is understood as interventions to modify a DNA sequence – nuclear or mitochondrial – through the introduction, deletion or modification of genes, maternal spindle transfer would not fall into that category as the process keeps both nuclear DNA and mitochondrial DNA intact.
Article 13 of the Convention authorizes the modification of human genome for preventive, diagnostic or therapeutic reasons, only when the purpose is not to introduce any modification in the genome of descendants. The article would apply to maternal spindle transfer if “descendants” refer to the children born as a result of the treatment, but if what is being prohibited is the introduction of modifications to the germ line that can be transmitted to subsequent generations, it would only be prohibited in relation to female embryo transfer as transferred male embryos would not pass unwanted side effects to future generations.
There is now an intense debate in Australia around the approval of a bill that would allow mitochondrial donation. One of the arguments against the bill is egg donation can safely prevent the transfer of mitochondrial disease from mother to child. This, however, means the mother would not be able to pass on her genes.
The Australian model resembles the United Kingdom’s dual license system. In Australia, only one clinic would be licensed to offer mitochondrial donation during the first phase, which is expected to last 10 to 12 years. Every patient who wishes to undergo the procedure will also need separate approval and be subject to eligibility requirements that are similar to those in the UK.
One major difference between the two models is the right to information on donor identification data: in Australia, this right would be extended to children born by mitochondrial donation, while in the UK, mitochondria donors can remain anonymous. The UK allows anonymity because they would contribute less than 1 percent to the child’s genetics. In both countries, children born after in vitro fertilization with egg or sperm donation have the legal right to obtain identifying information from their donors upon reaching the age of majority.
The UK rejected the possibility of choosing only to transfer male embryos, but, in Australia a third alternative was proposed: to let the parents decide whether to transfer a male embryo or proceed without sex selection. This intermediate proposal does not resolve ethical questions about sex selection. Also, even if parents receive counseling, they may not be equipped to make well-informed decisions.
Genetic identity makes human beings unique. Reproductive cloning involves replicating nuclear genetic identity. Given that mitochondrial substitution requires nuclear transfer to be carried out, it is important to analyze whether it contradicts international regulations on reproductive cloning, such as Article 11 of the Universal Declaration on the Human Genome and Human Rights (November 11, 1997), the Additional Protocol to the Convention of Human Rights and Biomedicine on the Prohibition of Cloning Human Beings (November 6, 1997), and article 3.2 of the Charter of Fundamental Rights of the European Union (December 7, 2000). It would seem that it does not: Persons born from mitochondrial substitution will not share the same nuclear genetic map as another human being, whether they are living or dead.
On the other hand, with regard to the concern over whether persons born by meiotic spindle transfer would develop some sort of identity crisis, it is worth noting that the presence of third-party DNA is already common in heterologous assisted fertility in the cases where the donation of male or female gametes, or both, are used.
During the debates in Australia, it was argued that the Mitochondrial Replacement Bill would open the door to ethically questionable practices. In principle, it would make it legal to produce and destroy embryos until a viable one is achieved for implantation. The practice would otherwise be prohibited in the country.
The interest in non-modification is centered on avoiding the selection of human beings. But taking into consideration the entire human species, it does not seem that the meiotic spindle transfer can be generalized on a scale of the magnitude necessary to produce an effect on the evolutionary process. The Australian Senate passed the bill at the end of March, the last hurdle for what is known as Maeve’s Law after Maeve Hood, a girl who inspired the legislation, to be adopted.
To make ethical judgments and legal decisions, it is necessary to weigh the different degrees of modification to genetic integrity produced by each of these techniques. There is a difference between genetic alterations that have therapeutic purposes, as opposed to determining physical, psychological or personality traits. Since the transfer of the meiotic spindle does not influence physical or personality, it would seem that ethical and legal objections are lower.
Other types of questions that arise include how countries should allocate funds from the health budget. If only those who can afford to pay for medical insurance had access to this new technique, the principle of equality would be broken, causing even more inequality by guaranteeing access to genomic techniques to high-income individuals.
Another question is how donor eggs should be obtained. They could be drawn from the existing pool of donated eggs for assisted fertility treatments, but that would mean that current egg donors may not have anticipated that their eggs would be used for mitochondrial donation and therefore have not specifically consented to that use. Eggs should be obtained from donors who have given specific consent.
If the benefits that are obtained through meiotic spindle transfer are bigger than the risks, it is likely that doctors and patients will continue using it. From current international regulations, it can be inferred that the transfer of the meiotic spindle is not completely prohibited, since the practice can be carried out in countries with more ambiguous regulations. As biologists, doctors and laboratories around the world may be qualified to execute such a procedure, specific regulations to govern the procedure would be necessary in most countries.