Mitochondrial Donation: The UK Experience

Abstract

Mutations in mitochondrial DNA (mtDNA) are inherited exclusively from our mothers and can cause a broad range of debilitating and fatal diseases. Reproductive technologies designed to uncouple the inheritance of the mitochondrial genome from the nuclear DNA genome may enable affected women to have a genetically related child with a greatly reduced risk of mtDNA disease. Such technologies involve transplantation of the nuclear DNA from the egg of an affected woman to an enucleated egg from an unaffected donor. Nuclear genome transplantation can be performed either before or after fertilisation. The latter involves transfer of pronuclei, which separately contain the maternal and paternal genomes. In parallel with legal and regulatory reform to permit therapeutic application of so called “mitochondrial donation” techniques in the UK, we have conducted preclinical studies to test the safety and efficacy of pronuclear transplantation (PNT). In 2017 Human Fertilisation and Embryology Authority (HFEA) approved the cautious use of PNT in the UK and granted the first licence for its therapeutic application in 2018. I will discuss the scientific, legal, and regulatory hurdles in the path from proof of concept to translation of mitochondrial donation to clinical treatment.