“Search and Destroy” by Stealth?

Last week’s publication, “Noninvasive Whole-Genome Sequencing of a Human Fetus,” by Kitzman et.al. in Science Translational Medicine, does not represent a Rubicon-crossing so much as a next logical step. It raises the well-described ills of devaluing unborn human life and the “soft eugenics” of parents attempting freely to choose their children’s biological characteristics. These issues were promptly addressed by seasoned observers such as Wesley Smith and the New York Times’s Ross Douthat.

Your intrepid correspondent paid the $15 for the article online and must report that he’s technically over his head, but that it is clear that this is a tour-de-force made possible by rapid gene sequencing and serious math/computer power. It’s also crucial that, as it turns out, DNA fragments float free in the bloodstream, and that up to 10-13% of that in a pregnant mom’s blood comes from the baby in the womb. That means that all of mom’s genes can be sequenced from her blood cells, all of dad’s genes can be sequenced from DNA obtained from his saliva, and when the information obtained from sequencing the free-floating DNA in mom’s blood is combined with these, predictions can be made about whether the baby might be affected with any one of about 3000 single-gene diseases. Then, when the baby is born, baby’s DNA can be sequenced—and the prediction turns out to be 98% accurate. Um—wow.

It’s all subject to the usual biomedical yada-yadas—it’s expensive for the moment, it needs to be validated, it was on a single case (actually two, but the article focuses on one)—but with refinements it will be here to stay.

Until now, this kind of prenatal diagnosis has required an invasive procedure—for example, amniocentesis—in which a sample is taken directly from the womb during pregnancy, with risks to the developing baby (and to a lesser extent, to mom). Oldsters like me will recall the 1980’s when Dr. C. Everett Koop—Christian, staunch defender of the unborn, Surgeon General, and pediatric surgeon extraordinaire—declared amniocentesis a “search and destroy mission,” because results were typically used to inform an abortion decision, not to prepare for the care or treatment of the baby on the way. So it seems with this new technique. It looks like the main application is to identify individuals who will not be born because of some genetic disease they will have. That’s happening now with Down syndrome (a chromosomal, not a single-gene, condition), but the use can be broadened.

So why did these scientists do this in the first place? There seems to have been no purpose other than to facilitate the abortion decision. Maybe there are future cures that this very early diagnosis will someday facilitate, but it seems terribly hard to guess at that—or at the value of pre-natal as opposed to immediately post-natal diagnosis. Besides the well-known considerations about embryofetal moral status and reproductive autonomy, it seems to me that this is another example where it is increasingly important to question the ultimate goals of scientific inquiry. Knowledge may not always be an unqualified good and is less and less pursued for its own sake, it appears to me. Certainly this paper was solely about technology.

Where might it lead? Personally, I doubt some sort of state-mandated use. Rather, a “consumer-oriented” regime seems more likely in our society. And will people use it to predict more complex traits? That also seems far off—the interpretation of the data would be prohibitively complex and expensive. But those computers are getting more powerful….

We have another occasion to say, “We shall not.”

PS—I was due to post yesterday, but got behind. But thanks to Dr. Jerry Risser for a terrific post on veterinary vs medical covenants.

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