Benefits of MRT
Several benefits exist for the use of MRT for IVF. First and most importantly, it is a strategy to allow couples to birth a biologically related child that does not have mitochondrial disease. In addition to the reduction in mitochondrial disease transmission, MRT may provide benefits for age-related infertility, where traditional IVF is unsuccessful. Despite these benefits, there has not been sufficient research to suggest that mitochondrial disease transmission can be lowered or avoided altogether by MRT, although preliminary research in animals may provide some insight into this in the future.
Scientific and Ethical Concerns of MRT
Although MRT can provide some families the benefit of having biological children without transmitting mitochondrial disease, there are some scientific and ethical concerns about the procedure. Reversal is cited as the main concern in MRT and involves carried-over mitochondria increasing over time, ultimately replacing donor mitochondria in cells. In a study by Costa-Borges et al., 1 out of 6 children born from MRT exhibited reversal, where 30-60% of mitochondria were inherited from the recipient despite a carryover rate of only 1% from the recipient egg. While the child studied did not have any risk for a mitochondrial disease, this is not always the case. This carryover rate may mean that MRT might not be successful in limiting mitochondrial disease in the offspring of individuals with mitochondrial mutations. One possibility to explain this may be that genetic factors from the recipient increase the efficiency of replication for their own mitochondria, compared to that from the donor. It may be necessary to find similarities in mitochondrial DNA between recipient and donor to reduce the risk of reversal.
Harms to egg providers with healthy mitochondria: Although egg donation is voluntary, it is not without its physical and psychological risks. Donors are required to undergo several interviews, screens, as well as hormonal stimulation and egg retrievals with no “benefit” of having a child. These hormonal treatments can cause acute physical pain (cramping, nausea, vomiting). Also, they can potentially cause longterm effects including but not limited to risk of cancer and decreased fertility. The ethics of egg donation comes into play when considering the financial aspect of egg donation, where economically disadvantaged people may become targets for this process. Harms to offspring: MRT still remains experimental, and as a result, long-term safety and efficacy must be investigated further. At this moment, there is no information on the impact that mixing genetic material and mtDNA may have on future progeny. Although there is always risk in new technologies, thereby necessitating the need for clinical trials, it is necessary to assess the technique in preclinical trials rather than foregoing these processes by conducting the procedures in countries without regulations against the technique. This introduces further ethical concerns into medical tourism.
Conclusions
Overall, MRT provides a rewarding solution for people who would like to have biologically related offspring without risking the transmission of mitochondrial disease. However, scientific and ethical concerns subject this technology to further scrutiny prior to its popularization. Ultimately, national health organizations must continue to objectively analyze the research into MRT and its future use. - Baweleta Isho
In addition to scientific concerns, ethical concerns have been raised regarding the use or MRT. These ethical concerns encompass various categories that can include harms to egg providers and harms to potential offspring. IMMpress Vol. 11 No. 2 2023
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