Ethical issues in manipulating the human germ line.

This essay examines the arguments for and against working towards the objective of human germ line engineering for medical purposes. Germ line changes which result as a secondary consequence of other well designed and ethically acceptable manipulations of somatic cells to cure an otherwise fatal disease can be seen as acceptable. More serious objections apply to intentional germ line interventions because of the unacceptability of using a person solely as a vehicle for creating uncertain genetic change in his descendants. It is also morally unacceptable to use the promise of future benefit to experiment on fetuses or embryos when other more effective technologies exist to help parents have healthy children. Using new genetic technologies to select desirable genotypes among gametes is less problematic and affords a promising new technique for avoiding intergenerational harms.