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Mitochondrial replacement techniques and Mexico

The birth of the first child after a mitochondrial replacement technique has raised questions about the legality of such procedure. In this post we explore some of the legal issues surrounding this case.

Mitochondria are cellular organelles that generate the energy cells need to work properly. Two interesting features of mitochondria are that they are solely inherited via the maternal line and that they possess their own DNA. This means that in human cells there is the nuclear DNA and mitochondrial DNA. Mitochondrial DNA, with its 37 genes, accounts for 0.1% of the total human DNA. Disorders caused by mitochondria not working properly have been named ‘mitochondrial diseases’. Mitochondrial diseases, as stated by the Nuffield Council on Bioethics, “can be caused by either problems in the genes in the nucleus affecting mitochondrial function, or by problems in genes within the mitochondria themselves”.

Scientists have recently devised two techniques that would allow women affected by mitochondrial DNA diseases to have genetically related children free from disease. These techniques have been called mitochondrial replacement technique (MRTs), although some object to this name. Both techniques consist in rehousing the intending parent(s)’s nuclear DNA into a previously enucleated cell that has healthy mitochondria. In one of the techniques, Maternal Spindle Transfer (MST), the nuclear DNA that is rehoused is that of an unfertilised egg. In the other technique, Pronuclear Transfer (PNT), the nuclear DNA that is rehoused is that of a zygote.

Now, the birth of the first child after an MRT, MST in this case, took the world by surprise. While everyone was expecting for this to happen in the United Kingdom, the only country in the world with explicit legislation regarding these techniques, Dr. John Zhang, from New Hope Fertility Center, beat everyone to the punch. In September 2016, New Scientist broke the news that the first MRT-conceived baby had been born on 6 April 2016. The boy, who seems to be healthy, was born to a Jordanian couple who had previously lost two children to a mitochondrial DNA disease.

This remarkable accomplishment was met with both awe and criticism. As Nature puts it, “In interviews and at meetings, researchers and experts raised vague doubts about whether the New Hope team had properly informed their patients, or whether it had broken laws”. We think that this criticism was accentuated by the fact that Zhang was quoted saying that they went to Mexico because “there are no rules” there (although it is reasonable to suppose that Zhang was talking about the fact that in Mexico there are no specific rules governing MRTs).

MST locations
The arrow states where MST was carried out. Purple, states where human life is protected from the moment of conception (i.e. implantation). Green, states where PNT is prohibited because human life is protected from the moment of fertilization. Orange, state where PNT is prohibited if the would-be-enucleated embryo is first created for a non-reproductive purpose. Image provided by the author and used with permission.

In order to address some of the issues we decided to explore the legality of MRTs in Mexico. We reached the conclusion (according to how we interpreted the law and with the available information about the case) that Zhang’s team broke Mexican federal regulations, specifically the Regulations of the General Health Law on Health Research. Before saying why we think this is the case, here is a brief overview of some of the Mexican laws that relate to MRTs.

There is no explicit federal law in Mexico that protects human life from the moment of fertilization or conception, and the Mexican Supreme Court’s latest ruling on an abortion case has asserted that at the federal level there is no recognised right to life from the moment of conception or fertilization either. This entails that PNT is, in principle, not outlawed at the federal level.

The only Mexican federal law concerning genetically modified organisms, the 2005 Law on the Biosafety of Genetically Modified Organisms, explicitly excludes in its Article 6, section V, the human genome and the modification of human germ cells from its oversight. And it defines GMOs, in Article 3 section XXI, as:

Any living organism, with the exception of human beings [emphasis added], that has acquired a novel genetic combination, generated through the specific use of techniques of modern biotechnology […]

This means that at the federal level neither MST nor PNT are in principle outlawed. At state level, however, things are different. Mexico is a federal republic composed of 32 states; each state has its own constitution. Of those 32 states, nine have laws that protect human life from the point of fertilisation, and nine have laws that protect human life from conception. According to a ruling of the Inter-American Court of Human Rights, that applies to Mexico, conception should be understood as the moment at which implantation occurs. This means that in those states with laws protecting human life from the moment of fertilization, PNT is prohibited given that it intentionally destroys a human embryo for the benefit of another one.

Zhang’s team broke the Regulations of the General Health Law on Health Research, according to how we interpreted the law and with the available information about the case, because they did not aim at solving a sterility problem. Article 56 of such regulations state that:

Research on assisted fertilization will only be admissible when it is applied to solve sterility problems that cannot be solved otherwise [emphasis added], respecting the couple’s moral, cultural, and social points of view, even if these differ from those of the researcher.

Sterility is defined as the failure to achieve a clinical pregnancy after 12 months of regular unprotected sexual intercourse. If research on MST is used to solve sterility problems that cannot be solved otherwise then it would not violate Article 56; if research on MRTs is not used to solve sterility problems that cannot be otherwise solved then it would violate Article 56. In Zhang’s team’s case their research included a woman who could get pregnant and deliver a live baby and thus violated Article 56 of the Regulations of the General Health Law on Health Research.

Featured image credit: IVF by DrKontogianniIVF. CC0 public domain via Pixabay.

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