Mitochondrial transfer: Ethical, legal and social implications in assisted reproduction

Abstract

Diseases resulting from mutations in mitochondrial DNA (mtDNA) are inherited by all offspring through the maternal lineage. Multiple organs, which require high cellular energy production, are severely affected. Currently, no preventative treatments are available, with most patients experiencing a poor quality of life or death in childhood. With developments in mitochondrial transfer techniques, hope for preventing transmission of mutated mtDNA onto offspring is emerging. However, many ethical issues have been raised in the health and public sectors regarding these novel treatment options, which involve transfer of nuclear material into donated oocytes with healthy mitochondria, or introduction of healthy donor mitochondria into affected oocytes. Several methods have been explored – blastomere, ooplasmic, pronuclear and spindle transfer. The two latter techniques seem to be the most viable thus far. The primary ethical concerns of these novel technologies are related to (a) the alteration of germ line genetics and (b) the dilemma of children inheriting DNA material from three instead of two parents. In contrast to the widely accepted practice of gene therapy, where only the DNA of the treated individual is affected, the techniques in question involve introduction of foreign mtDNA into the germ line that will be inherited by all children in downstream generations. Mitochondrial transfer has also been closely associated with reproductive cloning, which is regulated differently worldwide. It has also been suggested that mtDNA transfer will cause psychosocial problems for children born from these techniques, as they might experience an identity crisis. Undeniably, three gametes are needed to produce a healthy embryo in this scenario. However, the child will inherit all nuclear DNA from the intending parents, while only inheriting mtDNA from the donor. It is imperative to consider both social and scientific values when introducing new healthcare technology. At a level of social and moral principles, many people believe that some assisted reproductive technology techniques go beyond the limits of acceptable medical intervention. It is important to take these opinions into consideration, but who ultimately decides what is acceptable and what is not? In this review we will address the ethical and social issues surrounding this emerging new technology. Additionally, legal developments regarding its clinical introduction in the United Kingdom and the USA, and the impact on technique and patient management in the future will be discussed. Legislation related to genetic manipulation in South Africa will also be considered in this context.