Egalitarian Justice and the Prevalence Principle in Human Genome Editing

National and international agencies and organizations are currently considering which ethical principles should inform the governance and use of heritable and non-heritable human genome editing. In this paper, we consider the prevalence principle, according to which heritable and non-heritable genome editing in humans is permissible if and only if it involves the conversion of variants to ones expected to produce traits that are prevalent in the relevant population. This principle thus permits genome editing targeting variants responsible for disease and disability but prohibits genetic enhancement. We consider whether the prevalence principle is supported by considerations of egalitarian justice, as its proponents claim. We argue that it is not and that prominent theories of egalitarian justice instead offer different approaches to genome editing governance. We identify four egalitarian principles policymakers should consider when crafting anticipatory guidance for heritable and non-heritable genome editing.