Should Long-Term Follow-up Post-Mitochondrial Replacement be Left up to Physicians, Parents, or Offspring?

UK law permits parents to use mitochondrial replacement (MR) to have genetically-related children without serious mitochondrial disease. However, long-term follow-up is required for each case. Whether this follow-up should be left to physicians, parents, or offspring has not been established. Due to the experimental status of MR, physicians must inform parents of the risks and the importance of follow-up tailored to a specific mitochondrial disease. Given that the use of MR is a responsible exercise of reproductive freedom, parents should ensure that the follow-up is performed properly and in the best interests of their offspring. On becoming legally competent, the resulting children should be entitled to refuse follow-up provided that the prevention of mitochondrial disease with no adverse effects has been evident till then. This offspring-centred long-term follow-up approach might also be applied to the use of MR for infertility treatment, even though the primary endpoint is healthy live births.

Safety of Germline Genome Editing for Genetically Related "Future" Children as Perceived by Parents

The social acceptability of germline genome editing (GGE) depends on its perceived safety, as well as respect for reproductive autonomy. However, it is doubtful that prospective parents sufficiently understand the risks of GGE. In the future, the use of GGE in specific situations seems plausible, as it offers couples potential means to safeguard genetically related future children from a serious disease and overcome infertility due to a gene mutation. Should GGE fail, however, some couples may be obliged to abort affected fetuses, or give birth to adversely affected children, which would be a tragedy. Some children might develop diseases later in life due to overlooked off-target mutations. Compounding this, some parents are unlikely to inform their offspring about the details of conception, hampering necessary follow-up. Prospective parents, scientists and policy makers should carefully discuss the safety implications of GGE for genetically related future children.

Mitochondrial Replacement Techniques: Genetic Relatedness, Gender Implications, and Justice

In 2015 the United Kingdom (UK) became the first nation to legalize egg and zygotic nuclear transfer procedures using mitochondrial replacement techniques (MRTs) to prevent the maternal transmission of serious mitochondrial DNA diseases to offspring. These techniques are a form of human germline genetic modification and can happen intentionally if female embryos are selected during the MRT clinical process, either through sperm selection or preimplantation genetic diagnosis (PGD). In the same year, an MRT was performed by a United States (U.S.)-based physician team. This experiment involved a cross-border effort: the MRT procedure per se was carried out in the US, and the embryo transfer in Mexico. The authors examine the ethics of MRTs from the standpoint of genetic relatedness and gender implications, in places that lack adequate laws and regulation regarding assisted reproduction. Then, we briefly examine whether MRTs can be justified as a reproductive option in the US and Mexico, after reassessing their legalization in the UK. We contend that morally inadequate and ineffective regulations regarding egg donation, PGD, and germline genetic modifications jeopardize the ethical acceptability of the implementation of MRTs, suggesting that MRTs are currently difficult to justify in the US and Mexico. In addition to relevant regulation, the initiation and appropriate use of MRTs in a country require a child-centered follow-up policy and more evidence for its safety.