Abstract

The February 1997 announcement of the birth of Dolly, the sheep cloned from a mammary cell of an adult ewe, has drawn attention to the growing ability to select, alter, or otherwise manipulate the genome of offspring. Prior to Dolly, ethical discussion of genes in reproduction had focused on negative selection: carrier screening, prenatal diagnosis, and abortion or embryo discard. After Dolly, ethical debate will have to consider the direct or positive use of genetic selection or alteration technology.The principal use of genetic selection techniques in human reproduction likely will be to treat or prevent disease in offspring. In the future, however, such techniques might also be used to enhance or even diminish expected characteristics of progeny. Techniques to accomplish these goals are likely to include: selection of the nuclear genome, as occurs in somatic cell cloning; chromosomal transplants; or direct insertion or deletion of specific genes.