Mitochondrial donation is a technique used in IVF to replace defective mitochondria with healthy ones from a donor. It’s been approved for use in the UK and Australia to prevent the transmission of mitochondrial disorders.
Since the technique creates embryos with the DNA of three individuals, which can lead to "three−parent babies," the technique has raised different ethical concerns. In this post, we'll look at three of these concerns: the concept of "three−parent babies," whether mitochondrial donation is a form of genetic modification, and the ethical implications of techniques that may involve destroying fertilized eggs.
Mitochondrial Donation & the Creation of “Three−Parent Babies”
Mitochondrial donation involves replacing faulty mitochondria in a parent's egg or embryo with healthy mitochondria from a donor. This process creates an embryo with DNA from three individuals: the nuclear DNA from the parents and the mitochondrial DNA from the donor. It has led to the term “three−parent baby.”
Difference Between Nuclear DNA and Mitochondrial DNA
Nuclear DNA, inherited from both parents, comes from inside the nucleus of cells and is the primary determinant of an individual's genetic traits, such as physical characteristics like eye color or height. Mitochondrial DNA is found in the mitochondria outside the nucleus of cells and is primarily involved in the cell's energy production and metabolism.
The term “three−parent baby” implies a genetic relationship through mitochondrial donation. However, the UK, the first country to legalize this procedure, has specified that a child's genetic traits come solely from the nuclear DNA of the parents, not from the mitochondrial DNA of the donor (UK Department of Health 2014):
“In using these techniques, the resulting child will have nuclear DNA (99.9%) from their father and mother and healthy mitochondrial DNA (0.1%) from a female donor. Genetically, the child will have DNA from three individuals; all available scientific evidence indicates that the genes contributing to personal characteristics and traits come solely from the nuclear DNA, which will only come from the proposed child’s mother and father. The donated mitochondrial DNA will not affect those characteristics.”
What Are the Perspectives of Donors and Recipients?
Researchers in a 2024 study surveyed women to see if they would be more likely to consider egg donation if it were done using pronuclear transfer (a mitochondrial donation technique). While nearly 95% of women were concerned about the genetic contribution of donated eggs, 70% indicated that they would reconsider if the pronuclear transfer technique were used. In another 2024 survey, 56% of women would consider themselves a genetic parent of a child born from mitochondrial donation, and there was no difference in their willingness to donate by mitochondrial donation or standard egg donation.
Based on these studies, some women are open to reevaluating their decision to donate eggs when a mitochondrial donation is used, as it could help reduce concerns about genetic contribution.
Is Mitochondrial Donation Considered Genetic Modification?
Genetic modification is the process of altering the genetic material of an organism in a laboratory to enhance or change its characteristics. It is typically done by adding new DNA, modifying existing DNA, or removing DNA. Mitochondrial donation is often considered a genetic modification because it involves replacing defective mitochondrial DNA in an egg with healthy mitochondrial DNA from a donor. Because of this, many countries prohibit mitochondrial donation as they see it as a type of genetic modification.
How Do the UK and Australia Define Mitochondrial Donation?
When the UK permitted the use of mitochondrial donation, they adopted a “working definition” of genetic modification that excluded mitochondrial DNA and focused instead on the modification of nuclear DNA (UK Department of Health 2014):
“There is no universally agreed definition of “genetic modification” in humans – people who have organ transplants, blood donations, or even gene therapy are generally not considered “genetically modified.” While there is no universally agreed definition, the government has adopted a working definition to implement these regulations. The working definition that we have adopted is that genetic modification involves the germline modification of nuclear DNA (in the chromosomes) that can be passed on to future generations. It will be kept under review.”
In response, the UK government was accused of misleading the public, with critics arguing that the government redefined genetic modification to push the regulations forward and avoid public backlash.
Besides the UK, Australia also legalized mitochondrial donation through Maeve’s Law in 2022. Instead of redefining genetic modification, they clarify that changes to mitochondrial DNA do not impact a child's characteristics or identity (Ludlow 2022). The Mito Foundation, an Australian organization that supports individuals with mitochondrial disorders and sponsors research, does not classify mitochondrial donation as genetic modification. It is based on two points: firstly, the technique does not alter nuclear DNA, and secondly, it involves replacing all defective mitochondrial DNA rather than modifying it.
Does Mitochondrial Donation Involve Destroying Fertilized Eggs?
Mitochondrial donation can be performed in different ways, with maternal spindle transfer (MST) and pronuclear transfer (PNT) commonly used. MST involves using an unfertilized human oocyte that is later fertilized, while PNT uses two already fertilized oocytes (zygotes). PNT usage can lead to more ethical debates than MST because it involves zygote manipulation and eventual discarding (Craven et al., 2018). This aspect can be troubling for those who believe life begins at fertilization. MST doesn't involve the destruction of a zygote and is viewed by some as more ethically acceptable because it involves unfertilized eggs.
However, the definition of when life begins is not universally agreed upon, and the creation of the embryo's DNA is not finalized until after the pronuclei fuse. Therefore, the ethical debates surrounding PNT might be seen as exaggerated since "new life" has not been fully established.
Why Choose International Fertility Group?
At International Fertility Group (IFG), we specialize in offering advanced mitochondrial donation services developed to help families overcome the challenges of genetic diseases or age−related fertility challenges. Our state−of−the−art technology and a team of leading fertility experts ensure the highest care and precision in every case.
By choosing IFG, you can access personalized treatment plans, cutting−edge laboratory facilities, and a dedicated support team that guides you through every step of your fertility journey. Trust us to bring you closer to the family you've always dreamed of, with safety, professionalism, and success at the forefront of our services!
Conclusion
Mitochondrial donation raises different ethical issues, such as using genetic material from three people and the potential destruction of embryos. Even though it does not alter the nuclear DNA that defines our physical traits, it still challenges how we define genetic modification.
As technology progresses and becomes more accepted worldwide, it is crucial to keep discussing these ethical issues and weigh them against the health benefits of the technique!
