Reproductive CRISPR does not cure disease.

Given recent advancements in CRISPR-Cas9 powered genetic modification of gametes and embryos, both popular media and scientific articles are hailing CRISPR's life-saving, curative potential for people with serious monogenic diseases. But claims that CRISPR modification of gametes or embryos, a form of germline engineering, has therapeutic value are deeply mistaken. This article explains why reproductive uses of CRISPR, and germline engineering more generally, do not treat or save lives that would otherwise have a genetic disease. Reproductive uses of CRISPR create healthy people whose existence is not inevitable in the first place. Creating healthy lives has distinct and lesser moral value from saving or curing lives that would otherwise have genetic disease. The real value in reproductive uses of CRISPR is in helping a very limited population of people have healthy, genetically related children. This diminished value cannot compete with the concerns in opposition to germline engineering, nor is it worth the investment of research money.