Fact Check: "Human babies with two fathers would technically be three-parent babies."
What We Know
The claim suggests that a human baby with two fathers would be classified as a "three-parent baby." This idea is rooted in the concept of mitochondrial replacement therapy (MRT), which allows for the use of genetic material from three individuals: one male and two females. In this process, the nuclear DNA from the mother and father is combined, while the mitochondria (which contain their own DNA) are sourced from a female donor. This means that the resulting child inherits DNA from three people: the nuclear DNA from both fathers and mitochondrial DNA from the donor (How can a baby have three parents?, Baby born from three people's DNA in UK first).
Mitochondria are essential for energy production in cells and are passed down maternally. Therefore, while the majority of a child's traits are determined by nuclear DNA, the mitochondria contribute a small percentage of the overall genetic makeup. The mitochondrial DNA (mtDNA) from the donor does not influence traits like appearance but is crucial for cellular energy functions (Three-parent baby | Definition, Process, History, & Facts).
Analysis
The claim that a baby with two fathers would be a "three-parent baby" is partially true. While it is accurate that mitochondrial DNA can come from a third party, the context of the claim is critical. In traditional scenarios involving two fathers, the third "parent" (the mitochondrial donor) would not be involved in the conception process unless MRT is utilized.
The process of MRT is specifically designed to prevent mitochondrial diseases by replacing defective mitochondria with healthy ones from a donor. This technique has been successfully implemented in some cases, leading to the birth of children with genetic contributions from three individuals (Baby born from three people's DNA in UK first, Three-parent baby raises issues of long-term health risks). However, the term "three-parent baby" can be misleading, as the mitochondrial contribution is minimal (around 0.1% of the total DNA) and does not affect most inherited traits (How can a baby have three parents?, Three-parent baby | Definition, Process, History, & Facts).
Moreover, the ethical implications and long-term health risks associated with MRT are still under scrutiny, and the practice is not universally accepted or legal in all countries (Baby born from three people's DNA in UK first, Three-parent baby raises issues of long-term health risks). Thus, while the biological mechanics allow for a third genetic contributor, the practical application of this concept in the context of two fathers remains limited and complex.
Conclusion
The verdict is Partially True. While it is scientifically accurate that a child can inherit mitochondrial DNA from a third party, the claim oversimplifies the complexities of human reproduction and the implications of being classified as a "three-parent baby." The involvement of two fathers in a traditional sense does not inherently create a three-parent scenario unless mitochondrial replacement therapy is employed, which is not a common practice for all couples.
