I’m sick of reading about the dangers of the genome. There are lots of popular articles I could point to, but let’s start with a recent series in Time that included eight online features and the Dec. 13 cover story, ominously titled “The DNA Dilemma.”
The series, written by Bonnie Rochman, is thoroughly reported, balanced, and full of fascinating personal stories about children whose genomes have been sequenced. It’s also timely: The primary question Rochman raises—how much information is too much information?—has been dominating commentaries about genetic testing in the medical literature.
But this is the wrong question, or at least one that’s becoming increasingly irrelevant. The personal genomics horse has bolted, and yet many paternalistic members of the medical community are still trying to shut the barn door. In doing so, they’re fostering a culture of DNA fear when what we really need is a realistic and nuanced genetics education.
There are many kinds of genetic tests, but most of the hoopla revolves around whole-genome sequences—the impossibly long, letter-by-letter readouts of the DNA inside the nucleus of each of your cells. In 2003, the first human genome was fully sequenced for just shy of $3 billion. Today a doctor can order yours for around $10,000.
Though dropping every day, the cost is still prohibitive enough that most people who get their genome sequenced are part of a medical research study. But the technology is beginning to seep into everyday clinical settings, especially for children with rare diseases. In either situation, the doctor or researcher might inadvertently discover genomic information—known as “incidental findings” in the scientific literature and “dark DNA secrets” in one of the Time articles—that has nothing to do with the child’s sickness or the study at hand. Hence the big dilemma: How much do patients want to know? How much do they need to know?
This so-called "return of results" is one of the hottest issues in genetics and will only get more pressing as genetic testing becomes cheaper and more routine. Last year, the National Human Genome Research Institute set aside $40 million for studies about how genome sequences can be applied in a medical setting, including $5.5 million for projects on returning research results to participants. No fewer than 28 scientific reports on the subject appeared in 2012 alone, as did an editorial in the journal Nature.
The public discussion about DNA testing tends to focus on ethical dilemmas: What if doctors find that a person’s father isn’t really? Should they tell a patient about a DNA glitch if it's only occasionally linked to disease? What if, while looking for mutations that could explain a known sickness, they stumble on others that might predict late-life dementia or indicate the presence of HIV? Would adding this data to someone's medical record affect health insurance rates? What if—gasp—we end up with a real-life Gattaca?
These questions are worth talking about. But the genetics community and popular press spend too much time debating when and how the medical establishment should "protect" people from their children’s or their own DNA.
For example, many bioethicists argue that DNA glitches shouldn’t be disclosed if they’re ambiguous or linked to untreatable conditions. Doing so "may create unwanted psychosocial burdens on parents," according to a commentary on newborn sequencing in the Journal of the American Medical Association.
Here’s a real-life example of how that philosophy can play out. As described in one of the Time stories, researchers at the Children’s Hospital of Philadelphia screened the genome of a sick baby and discovered a genetic variant that is linked to dementia around age 40. Because the researchers apparently hadn’t asked the parents ahead of time what extra genetic information (unrelated to the illness) they would want to know, the researchers were in a tough spot. They ultimately decided not to tell the parents about their child’s dementia risk. “We came around to the realization that we could not divulge that information,” one of the geneticists told Time. “One of the basic principles of medicine is to do no harm.”
Though I’m sure the researchers meant well, their implicit message—that a nonexpert couldn’t possibly understand the concept of an uncertain risk and would therefore be harmed by the knowledge—is not only patronizing but probably false.
I learned a lot about uncertain risk thanks to 23andMe, a private company that for $99 screened a tube of my spit for about 1 million SNPs, or common genetic variants that are associated with small increases or decreases in the risk of various diseases. I received my results (all of them) on an easy-to-use website. I found out that I have an elevated risk of heart disease and melanoma, among other ailments. My immediate reaction was panic, I’ll admit, but after chewing on the information I realized it wasn’t all that scary.
My response is pretty typical. Last year, the New England Journal of Medicine published a study of how more than 2,000 people reacted to getting SNP results from another direct-to-consumer genetic testing company. The bottom line: Nobody freaked out. Six months after testing, people who received this information didn’t show any differences in anxiety compared with those who didn’t receive it.
Part of the reason for the ho-hum reactions, mine included, is that SNPs are notoriously ambiguous: Sometimes they point to disease and other times they don’t. Whole-genome sequences, in contrast, sometimes finger rare mutations that are far more predictive—and more frightening.