Novel technological developments mean that gene editing – making deliberately targeted alterations in specific genes – is now a clinical reality. The inherited metabolic disorders, a group of clinically significant, monogenic disorders, provide a useful paradigm to explore some of the many ethical issues that arise from this technological capability. Fundamental questions about the significance of the genome, and of manipulating it by selection or editing, are reviewed, and a particular focus on the legislative process that has permitted the development (...) of mitochondrial donation techniques is considered. Ultimately, decisions about what we should do with gene editing must be determined by reference to other non-genomic texts that determine what it is to be human – rather than simply to undertake gene editing because it can be done. (shrink)