Screening embryos for eye, hair, and skin color.

Science, technology, and life.
Feb. 17 2009 8:10 AM

Color ID

Screening embryos for eye, hair, and skin color.

Human embryo. Click image to expand.
Human embryo

Is the era of designer babies finally here?

William Saletan William Saletan

Will Saletan writes about politics, science, technology, and other stuff for Slate. He’s the author of Bearing Right.

Every week, it seems, we're told that this discovery or that technology might lead to "designer babies." I've heard this so many times that I've stopped taking it seriously. Genetic engineering always turns out to be more complicated than expected, and our latest technology always turns out to be less capable than advertised.

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But now trait selection seems to be coming into view for real.

Two months ago, the Fertility Institutes, an assisted reproduction company headquartered in Los Angeles, began advertising the "pending availability" of genetic tests that would offer "a preselected choice of gender, eye color, hair color and complexion" in artificially conceived children. On Thursday, Gautam Naik of the Wall Street Journal reported that "half a dozen" potential clients had contacted the company to request such tests. As of today, the tests still aren't for sale. But several trends are converging to make aesthetic trait selection an impending business.

1. Embryo screening has become permanently entrenched. By now, tens of thousands of embryos have been screened for quality and potential disease, thanks to preimplantation genetic diagnosis. Culturally and politically, there's no going back.

2. Screening is steadily expanding to traits that are less medically important. We're examining and discarding embryos for flaws that are less lethal, less harmful, less likely to cause disease, and less likely to strike early in life. Two years ago, British regulators approved PGD to get rid of embryos that might become grotesquely cross-eyed. At the time, the head of the clinic that pioneered this use of PGD predicted, "We will increasingly see the use of embryo screening for severe cosmetic conditions."

3. Aesthetic screening is spreading. Once you're screening for "severe" cosmetic conditions, you can no longer rule out other cosmetic criteria. The principal gateway to aesthetic use of PGD is sex selection. Worldwide, the number of embryos and fetuses discarded for being the wrong sex is in the millions. In this country, the number of clients paying for sex-selective PGD is in the thousands and growing. Nearly half of U.S. clinics that offer PGD have used it for nonmedical sex selection, and 40 percent of Americans approve of this practice. The Fertility Institutes explicitly frames eye, hair, and skin color selection as an extension of sex selection.

4. A market for nonmedical trait selection is emerging. Naik points to a New York University survey of patients seeking genetic counseling. In the survey, published three weeks ago, 10 to 13 percent of respondents said they would use PGD to select height, athletic ability, or intelligence. NYU spins this as a tiny minority. But in raw numbers, it's easily enough to attract opportunistic entrepreneurs.

5. Aesthetic trait selection is becoming feasible. This used to be the sticking point in bringing the technology to market. No more. Naik reports:

In October 2007, scientists from deCode Genetics of Iceland published a paper in Nature Genetics pinpointing various [genes] that influence skin, eye and hair color, based on samples taken from people in Iceland and the Netherlands. Along with related genes discovered earlier, "the variants described in this report enable prediction of pigmentation traits based upon an individual's DNA," the company said. … William Kearns, a medical geneticist and director of the Shady Grove Center for Preimplantation Genetics in Rockville, Md., says he has made headway in cracking the problem. In a presentation made at a November meeting of the American Society of Human Genetics in Philadelphia, he described how he had managed to amplify the DNA available from a single embryonic cell to identify complex diseases and also certain physical traits. Of 42 embryos tested, Dr. Kearns said he had enough data to identify [genes] that relate to northern European skin, hair and eye pigmentation in 80% of the samples.