Would it surprise Catholics to learn that the Church does approve of gene editing in certain therapeutic cases?I don't think most Catholics would be surprised to learn that the Church would allow for gene editing to fix genetic abnormalities (as long as the risks were low for the patient, and heritable changes to the DNA of our species were not made). Such repair is simply a form of direct medical therapy for the patient. The reason a few Catholics might be "surprised" is because they may not be familiar with the real (and complex) science of genetic modification, and haven't had the opportunity to think it through beyond a few dramatized Hollywood depictions.                                            How do you tell the difference between valid gene therapy and gene enhancement, which is forbidden by the Church?The line separating a therapy from an enhancement is not always obvious. For example, at what point, in terms of developmental disabilities in a person with intellectual impairment, would we say that a particular genetic intervention was a therapy, rather than an enhancement? Suppose we choose IQ as a kind of yardstick (with normal IQ falling somewhere between 90 and 110), and supposing further that a patient had an IQ of around 80 (typically considered "dullness" or "borderline deficiency"). What if we could offer a genetic modification to some of his brain cells that would boost his IQ? If we could raise his IQ to around 125 (typically considered "very superior intelligence"), would this be a therapy or an enhancement? What if the gene therapy only improved the patient's IQ to 115? Et cetera. What if only certain features of his reasoning could be super-enhanced, like handling numbers and mathematics? Would this be a therapy or an enhancement? As you can see, these are complex questions.

With gene editing becoming relatively easy and inexpensive, some bioethicists fear that the world will eventually have two distinct populations — the genetically enhanced and those who aren’t. What do you think?  If germ-line editing becomes commonly accepted, and lines of human beings are routinely "enhanced" in the future, there could eventually arise diverse populations manifesting differing degrees of enhancement. Germ-line editing and making permanent modifications to future generations of humans should not be done. Those who encourage such practices suggest that parents should have the right to make changes to their children to help them and future generations, but the science, including the unintended effects, is only dimly understood at this point. I'm reminded of the commonly-cited example in which the tp53 gene was genetically modified in mice to offer them protection from cancer but which unexpectedly also contributed to premature aging of the animals.

Parents should receive any future children unconditionally, regardless of their imperfections or defects, rather than viewing them as fodder for genetic manipulation in order to satisfy their own parental needs and desires. The child's interests should objectively trump those of the parents, and as Eric Lander noted in a recent article in the New England Journal of Medicine: "... parental autonomy must be weighed against the interests of future generations who cannot consent to the genetic modifications their flesh will be heir to."

How close are we to having so-called “designer babies?”Designer babies are already being made today in the infertility clinics that offer the technique called pre-implantation genetic diagnosis, or PGD. This technique genetically screens embryos for certain desired traits, or screens out certain embryos for undesired traits, thus allowing parents to "design" their progeny with respect to discrete characteristics. The technique does not genetically modify the embryo, but merely discards those embryonic humans who might have undesirable features, but this is still a clear instance of designing our own offspring through selection.

Is this an issue Catholics should be greatly concerned about?Yes, Catholics should be concerned about the prospects of genetically modifying future generations. In the past, I would say that we Catholics largely missed the boat when it came to recognizing and articulating the moral unacceptability of creating children in test tubes and glassware, and now Catholics participate in in vitro fertilization at rates that probably don't differ significantly from the general population. Similarly, when genetic enhancement of children takes place in the future, considering the widespread lack of understanding and serious reflection on the moral and ethical issues involved, Catholics are likely to end up being swayed by the technological temptation and may end up, once again, "going along to get along.”