Genetic disorders and the ethical status of germ-line gene therapy.

Recombinant DNA technology will soon allow physicians an opportunity to carry out both somatic cell- and germ-line gene therapy. While somatic cell gene therapy raises no new ethical problems, gene therapy of gametes, fertilized eggs or early embryos does raise several novel concerns. The first issue discussed here relates to making a distinction between negative and positive eugenics; the second issue deals with the evolutionary consequences of lost genetic diversity. In distinguishing between positive and negative eugenics, the concept of malady is applied as a definitional criterion for identifying genetic disorders that could qualify for germ-line therapy. Because gene replacement techniques are currently unavailable for humans, and because even if they were possible the number of people involved would be quite small, the loss of diversity concern seems moot. Finally, we discuss the issue of iatrogenic disorders associated with gene therapy and discuss several 'real world considerations.'