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Choosing what kind of people there should be

by Jeffrey P. Kahn, Ph.D., M.P.H.
Director, Center for Bioethics
University of Minnesota

Reproductive medicine is in the news a lot lately, whether for creating embryos from three different parents or over talk of opening a clinic for human cloning overseas. An announcement this week about genetic testing of embryos is less the stuff of a science fiction novel than are the other breakthroughs, but is more important for what it says about our future.

A clinic in Chicago announced that it had used a technique called pre-implantation genetic diagnosis (PGD) to test embryos for a gene that increases the risk of cancer, in particular, cancer occurring in childhood. The testing was used by a couple who were concerned that they would pass on the gene to their children. They used in vitro fertilization to create embryos, which were then tested for the gene in question. Unaffected embryos were implanted in the wife's womb, and nine months later she gave birth to a baby boy who does not have the genetic cancer risk carried by his father.

Testing embryos isn't all that new, but until recently it was limited to the few genetic tests available, nearly all of which were for genes whose defects predicted disease with certainty -- cystic fibrosis, severe combined immune deficiency (the "boy in the bubble" disease) and other serious and often life-threatening conditions. But the mapping of the human genome is already yielding new information about the complicated relationships among genes, disease, lifestyle and the environment, all of which can be used to predict the health of future children. How should we think about testing embryos for diseases that may not occur until later in life, if at all? Does it matter which diseases or characteristics are chosen, and if so, what limits should there be on the use of genetic tests to select embryos?

Preventing disease or designing babies?

Genetic testing of embryos or fetuses (through older technologies such as amniocentesis), has until now been used to avoid disease, and has been limited by the tests available. But new genetic information leads to new questions. What counts as disease? Cancer and cystic fibrosis seem easy, but what about being painfully shy, or very short? All seem to have genetic predictors or genetic components, so should we limit genetic testing for such traits when tests become available? Most of the forthcoming genetic tests for cancer will predict the increased risk of the disease as compared to "normal," but by no means will they offer a certain diagnosis. Should they be used, and how? What about testing embryos for diseases that only occur later in life, such as Parkinson's or Alzheimer's disease?

Unfortunately, these seem to be the easier cases. With the flood of new genetic information that will arrive in the coming decades, we'll know much more about what determines all sorts of physical and personality traits as well as health and disease. We'll know what makes eyes blue, as well as what makes some people gifted musicians or great athletes. So why limit our choices to merely healthy children, when we can also choose talented, gifted, tall, or whatever else our sensibilities tell us will contribute to a promising future? For many, all this smacks a bit too much of eugenics, but to limit using such tests threatens our deeply held sense that parents' have the right to choose when and under what conditions they'll have children.

Working toward a genetic menu

The future will undoubtedly offer many more genetic choices as we think about what kind of children we'll have. But do we really want parents to be able to select the characteristics of their children much as we decide which options to purchase with a new car? How would we choose between an embryo with a 25 percent lifetime cancer risk and great musical aptitude and one with a 5 percent risk of early heart disease but only average musicality?

However individual parents might decide such impossible choices, our societies must decide whether to let them have the chance. Without policies that lay out guidelines and restrictions for the acceptable uses of genetic testing of embryos, the only limitations will be those of science. But the limitations of science are on what can be accomplished, not on what should be done with the accomplishments. It is our responsibility to decide how to put the fruits of science to work.

Visit the
"Ethics Matters" Archive
where you'll find other columns from Jeffrey Kahn
on a wide range of bioethics topics.

"Ethics Matters" is a biweekly feature from the
Center for Bioethics and CNN Interactive.



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