Jonee Grant
Genetics
April 23,2026
Critical Reading Assignment #3: Bioethics Paper
I oppose the use of mitochondrial DNA replacement therapy because it raises unresolved
ethical concerns about germline modification and long-term safety. While the goal of preventing
severe mitochondrial diseases is important, the current scientific uncertainties and ethical
implications make this technology premature for clinical use.
Mitochondrial DNA replacement therapy (mtDNA RT) is a reproductive technology
designed to prevent the transmission of mitochondrial disorders from mother to child (Mitalipov
& Wolf, 2014). The procedure replaces defective maternal mitochondria with healthy donor
mitochondria while retaining the nuclear DNA from the intended parents (Mitalipov & Wolf,
2014). Techniques such as spindle transfer and pronuclear transfer have shown promise in
reducing mutant mtDNA carryover in experimental models (Mitalipov & Wolf, 2014). Because
mitochondrial diseases can cause neurological decline, organ failure, and early death (Gorman et
al., 2016), the therapy aims to give affected families the possibility of having genetically related
children without the risk of passing on these conditions.
Despite its potential benefits, mtDNA RT presents significant ethical dilemmas. First, it
involves germline modification, meaning the genetic changes introduced are heritable and will
be passed to future generations (Mitalipov & Wolf, 2014). This raises concerns about altering the
human germline without fully understanding the long-term consequences. Second, the therapy
results in a child with three genetic contributors—nuclear DNA from the parents and
mitochondrial DNA from a donor—which raises questions about identity, parentage, and societal
perceptions of “three-parent babies” (Rulli, 2016). Third, the long-term safety of
mitochondrial-nuclear interactions remains uncertain. Mitalipov & Wolf (2014) emphasize that
even small amounts of mutant mtDNA carryover could expand over time, potentially
undermining the therapy’s purpose. Finally, allowing germline modification for disease
prevention may create a slippery slope toward broader genetic engineering applications,
including non-medical enhancements.
My position is grounded in scientific evidence and consideration of stakeholder impacts.
For children, the long-term risks are unknown, and they cannot consent to inheriting an
experimental modification that affects their germline (Rulli, 2016). Parents may feel pressure to
pursue the therapy without fully understanding the uncertainties, especially when facing the
emotional burden of mitochondrial disease. Donors contribute genetic material that will be
inherited indefinitely, raising questions about their rights and responsibilities. Society must
consider how normalizing germline modification could reshape ethical boundaries, regulatory
frameworks, and public trust in reproductive technologies.
Alternative options exist that avoid germline modification. Families can consider egg
donation, which eliminates the risk of transmitting mitochondrial disease without altering the
germline (Mitalipov & Wolf, 2014). Adoption provides a non-genetic but meaningful path to
parenthood. Preimplantation genetic diagnosis (PGD) can help identify embryos with lower
levels of mutant mtDNA, although it is not effective for all mitochondrial disorders (Gorman et
al., 2016). While these alternatives may not perfectly meet every family’s desires, they avoid the
irreversible ethical risks associated with mtDNA RT.
In conclusion, although mitochondrial DNA replacement therapy offers hope for families
affected by devastating diseases, the unresolved ethical concerns and unknown long-term
consequences make its clinical use premature. Until more research clarifies the safety of
germline modification and society establishes clear ethical boundaries, mtDNA RT should not be
implemented. Protecting future generations from uncertain risks outweighs the potential benefits
at this stage of scientific development.
References
Gorman, G. S., et al. (2016). Mitochondrial diseases. Nature Reviews Disease Primers, 2,
16080.
Mitalipov, S., & Wolf, D. P. (2014). Clinical and ethical implications of mitochondrial gene
transfer. Trends in Endocrinology & Metabolism, 25(1), 5–7.
Rulli, T. (2016). The mitochondrial replacement “therapy” myth. Bioethics, 31(5), 368–374.