Playing god? (Guest Editorial).

One definition of genetic engineering is an attempt to determine the characteristics of offspring using genetic technology. This would include prenatal genetic selection, cloning, the use of drugs derived by genetic technology, and the insertion of genes into a person or a cell line to enhance genetic and phenotypic qualities.

What is it that is so troubling about these activities?

Virtually everyone should be concerned about the safety of medical interventions, respecting the ancient dictum, "First, do no harm." Like any new drug, device, or technology, we want to be sure we know the risks of genetic engineering, and we want to know that the risks are commensurate with likely benefits for the children involved.

Many individuals, however, have expressed deeper moral concerns about genetic engineering, charging that physicians or scientists or parents using this technology are playing God. The problem with this concern is the difficulty of applying it in a consistent way. All of medicine involves interfering with nature, or "God's plan." If God intended us to have meningitis or cancer, who are we to interfere?

But that is what medicine is largely about. Of course, God made doctors, too, and we must be here for a purpose, presumably to prevent suffering and help individuals achieve their potential and enjoy life. It's either all part of God's plan or it isn't, but it's unclear how we should pick between the various technologies and conclude that God intended us to have ceftriaxone and liver transplants but not prenatal diagnosis or gene therapy.

Another common concern about cloning, the most controversial form of genetic engineering, is that a cloned child wouldn't have his or her own identity. A cloned child, critics say, would lack a genetic identity, since he or she would be an identical copy of his or her father or mother, if that were the source of the genome.

What's the problem with that? Naturally occurring identical twins are clones--genetic replicas of someone else--and they don't seem to lack a sense of identity, nor does being a twin interfere with normal psychosocial functioning. On the contrary, some studies have shown twins to be better adapted than non-twin controls.