Is selecting better than modifying? An investigation of arguments against germline gene editing as compared to preimplantation genetic diagnosis

BACKGROUND: Recent scientific advances in the field of gene editing have led to a renewed discussion on the moral acceptability of human germline modifications. Gene editing methods can be used on human embryos and gametes in order to change DNA sequences that are associated with diseases. Modifying the human germline, however, is currently illegal in many countries but has been suggested as a ‘last resort’ option in some reports. In contrast, preimplantation genetic (PGD) diagnosis is now a well-established practice within reproductive medicine. Both methods can be used to prevent children from being born with severe genetic diseases. MAIN TEXT: This paper focuses on four moral concerns raised in the debate about germline gene editing (GGE) and applies them to the practice of PGD for comparison: Violation of human dignity, disrespect of the autonomy and the physical integrity of the future child, discrimination of people living with a disability and the fear of slippery slope towards immoral usage of the technology, e.g. designing children for specific third party interests. Our analysis did not reveal any fundamental differences with regard to the four concerns. CONCLUSION: We argue that with regard to the four arguments analyzed in this paper germline gene editing should be considered morally (at least) as acceptable as the selection of genomes on the basis of PGD. However, we also argue that any application of GGE in reproductive medicine should be put on hold until thorough and comprehensive laws have been implemented to prevent the abuse of GGE for non-medical enhancement.