Moral Boundaries of Germline Gene Editing: A Reappraisal After CRISPR-Based Clinical Trials

Abstract

he 2018 announcement that a researcher had edited and implanted human embryos using CRISPR-Cas9, resulting in the birth of twins with an altered germline, forced bioethics to confront heritable genome editing as an urgent rather than speculative question.
This review reappraises the moral boundaries around germline editing several years after that scandal and roughly two years after the first CRISPR-based somatic therapies reached patients through conventional regulatory approval. It surveys the institutional aftermath of the He Jiankui affair, the major governance frameworks issued since, from the National Academies and Royal Society, the World Health Organization, and the Nuffield Council on Bioethics, and the underlying disagreement in the literature over whether the objection to heritable editing is fundamentally about safety or about something safety data cannot resolve. It then contrasts this unsettled germline debate with the comparatively rapid and successful translation of somatic gene-editing therapy for sickle cell disease, which raises its own distinct questions about global access and honest description of benefit rather than intergenerational consent. We conclude that governance instruments issued since 2018 have converged on shared procedural safeguards without resolving the deeper normative disagreement about whether heritable editing should ever be permitted, leaving that question for future clinical and regulatory decisions to confront directly.