- BIOETHICS FORUM ESSAY
It’s Time for the Times to Cut the Gene Hype
The New York Times recently ran a front-page story that gave free advertising to three companies that already are or soon will be hawking whole-genome scans. The reporter, Amy Harmon, wrote, “For as little as $1,000, and a small saliva sample, customers will be able to learn what is known so far about how the billions of bits in their biological code shape who they are.”
To be fair, Harmon did not ignore obvious worries about these tests – namely, that the information is partial, probabilistic, easily misinterpreted, and subject to change. Nor did she forget that the information can pertain to untreatable disorders or that insurers might someday want to use it. But her awareness of those problems was swamped by her enthusiasm, which compromised her ability to tell the real story about genetics research today: the more geneticists learn about DNA, the more they understand that the simple story they were telling just 10 years ago needs radical revision.
In a somewhat feeble attempt to temper Harmon’s enthusiasm, the Times gave Nicholas Wade a little bit of space, just after the end of Harmon’s story, for more soberly airing the concerns about mail-order genome scans. In the last paragraph of his piece, Wade mentions that, in September 2007, Craig Venter, the leader of the private arm of the initiative to map the human genome, published the full sequence of his own DNA, but “because so little is known about the meaning of variation at each site on the genome, there was not much of interest [Venter] could say about himself.” In short, Wade allows one of the fathers of genome scanning to acknowledge that, at this time, genome scans are pretty much worth bupkis.
So, aside from temperamental differences, what explains how a world-famous geneticist like Venter could suggest that we know so little while a good reporter like Harmon suggests that we know so much? To shed some light on that question, it helps to remember a bit about the recent history of genetics research into complex traits and disorders (a topic I treated in the Hastings Center Report supplement “Genetic Differences and Human Identities: On Why Talking about Behavioral Genetics Is Difficult and Important” [registration required] and that was treated at much greater length in Wrestling with Behavioral Genetics, edited by me, Audrey Chapman, and Nancy Press).
The great achievement of “classical” behavioral genetics, which used twin, adoption, and family studies, was to show that genetic differences can in principle help explain observed differences in virtually all complex traits and disorders. So, to answer the parenthetical questions that Harmon asks about her own tendencies in her article, yes, a tendency to obsess about information and ideas “is genetic,” and so is a tendency to waver about decisions. One might add that a tendency to engage in hyperbole or to sell snake oil is also “genetic,” in the limited sense that genetic differences will always, in principle, help explain why some people are more prone than others to exhibit those behaviors. Given that 30 years ago many people did not believe that genetic differences had anything to do with observed differences, the achievement of classical behavioral genetics should not be underappreciated.
But once classical behavioral genetics showed that genes matter, geneticists needed to take the next step to figuring out which genes matter and how they matter. Initially, “molecular” geneticists enjoyed some stunning successes in identifying mutations in single genes that caused complex disorders like Huntington’s, familial adenomatous polyposis, or cystic fibrosis. Those initial successes were so impressive that many reasonable people began to hope that researchers would find “genes for” complex traits or disorders like depression or IQ or aggression. And many researchers, with the help of university PR departments and reporters, began announcing the discovery of “genes for” those complex common traits and disorders.
But almost always, either those results could not be replicated or, if they could be, the identified gene could help account for only a small percentage of the difference between people who did and did not exhibit the trait. Rare “monogenic” diseases turned out to be a profoundly misleading model for understanding how genes influence the emergence of common disorders and traits.
For one thing, geneticists started to learn that common disorders and traits emerge out of mind-bogglingly complex interactions over time among many genes and many environmental variables. Also, they started to learn that how genes work is infinitely more complicated than was suggested by the so-called “central dogma” of genetics (one gene leads to one RNA, which leads to one protein). It turns out that one gene can code for many, perhaps thousands of proteins – and thus can be involved in myriad traits. It turns out that RNA doesn’t just deliver genetic information, but is intimately involved in gene expression (turning protein production up or down). It turns out that what once was called junk DNA, because it was thought to be of no real use in the work of cells, probably also plays a significant role in regulating protein production.
These sorts of wrinkles in the old-fashioned story about how genes work recently moved the leader of the public initiative to map the human genome, Francis Collins, to say: “The scientific community is going to have to rethink what genes are, what they do and don’t do, and how the genome’s functional elements have evolved.” He added, “I think we’re all pretty awed by what we’re seeing. It amounts to a scientific revolution.” Whereas mail-order genome scans allow purchasers to accept a wildly simple story, Collins is telling a staggeringly complex one.
Recent comments by Kari Steffanson, a founder of one of these mail-order genome scan companies, can be interpreted to suggest that a concern about simplification is peevish. Explaining why people want scans, he observes, “This is a playful activity, and there’s nothing wrong with being playful…. It’s in keeping with what people are doing in cyberspace on Facebook.” But Facebook isn’t charging people to share in the fun, nor is it trading on the prestige of one of the world’s largest organized science projects. Anyway, should the New York Times use its front page to hawk entertainment?