In an article in The New York Times Sunday Review, genetics counselor Laura Hercher described a man named Matthew Fender, who—after searching for heredity data through 23andMe—had placed his genetic test results into Promethease, a DNA search engine that probes such data for variants cited in the medical literature.
Fender had sought to learn his risk for developing a pulmonary embolism, the condition that had killed his sister, a seemingly healthy young woman of 23. The report didn’t mention that, but it did provide the alarming news that he carried a mutation (PSEN1) strongly associated with early onset Alzheimer’s, as well as two copies of a gene variant (ApoE4) that indicates greatly increased chances of developing late-onset Alzheimer’s.
After getting no satisfactory guidance from his primary care doctor and other professionals, Fender checked out a competing genetics company, Ancestry DNA, to see what his results there would say about the PSEN1 variant. They said nothing. He then persuaded his doctor to order the test, which proved negative.
End of story for Fender, although he said the experience led him to improve his diet and to consider using his technological skills to develop an app to assist people with dementia through voice-activated devices such as Siri and Alexa.
It’s worth noting that both companies claimed their tests were 99.9% accurate. Yet a 23andMe representative told Hercher that “a 99.9% accuracy can still mean errors.” And apparently, not every variant in their chip is even validated for 99.9% accuracy.
“The direct-to-consumer genetic testing marketplace is a regulatory Wild West,” wrote Hercher, who is the director of research at the Sarah Lawrence College Graduate Program in Human Genetics.
She’s also the host of an informative and entertaining podcast, “The Beagle Has Landed,” (named after Charles Darwin’s ship—not Charles Schulz’s Snoopy), designed for both professionals and “curious patients,” according to its introductory press release. One of her interviewees was Matt Fender.
Hercher explained that FDA Commissioner Scott Gottlieb announced in November a new regulatory approach that will allow companies like 23andMe to market some tests to determine health risks without premarket review. That change, Hercher observes, “is expected to usher in a rapid expansion of the consumer genetics industry.”
That means we consumers will need to better prepare ourselves to function in this new ”Wild West” by getting a better education on the important topic of genetics and the role it plays in our health—even as the field itself is changing all the time.
With that backdrop, I spoke with Hercher to elicit her opinions on how to view all these genetic data at this stage.
First, to her, the quest for information about one’s heritage, which she calls the “ancestry craze,” is a “mixed bag.” The positives she underscores are that people enjoy and are intrigued by learning about their forebears, and the process brings science and genetics into people’s lives.
But when people ask her if these quests yield legitimate information, she responds: “It’s accurate-ish. People think of this as their genealogy, but once you get past Mom and Dad, there’s a lot of randomness—you could inherit something important, or not.”
“People like to tell a story they can understand, a narrative that can explain why people turned out certain ways. Genetics also tells a story, but the risk we run is that when hearing it, we put aside other stories—involving culture and heritage, for example. It’s very hard to weave it all together.”
If we’re interested in our predecessors’ story, then their story is ours, she notes, and that’s valuable to us. “Genes are a part of that, but not all of it. Even among siblings: one person could have 34% Southern European heritage, while his brother registered 15%. Would that make sense? No. The tests don’t gather with that level of precision.”
Hercher analogizes a swimming pool, with some blue substance for African ancestry, red for Chinese, etc. “The testers scoop a sampling from a spot of genomes into a net, and they’ll get red, green, yellow,” she says. “Different tests reach down and get the same mix, but it’s not identical.”
To Hercher, the ancestry tests also tend to encourage a kind of tribal thinking and ignore the overriding message: 99% of our DNA identifies us as human and is genetically shared among us. “The DNA story is our commonality as a people—as well as with other living things. I wish these companies presented the data in a way that made that clear.”
And this commonality has great implications for the subject of race. “No quality geneticist will tell you that the concept of race does a good job of describing our shared genetic ancestry. Race isn’t a scientific grouping; it’s defined culturally. There’s more mixture within groups than between groups.” In a point that is probably obvious to all but the most rabid white supremacists, she says: “Racial purity is a myth.”
Those in the genetics field are disturbed by the current efforts to bring back eugenics, or “scientific racism,” which was once believed even by serious scientists who felt they could, by controlled breeding, create an increase in desirable heritable traits and a decrease in undesirable ones, thereby improving the human race.
The concept was easily manipulated and became discredited after its use by the Nazis in Germany. “Now all these things are widely talked about,” Hercher laments. “The white nationalist movement has adopted the language of hate ideology and put a scientific gloss on it.”
This is the background for the hot water that Massachusetts Senator Elizabeth Warren has gotten herself into by taking a DNA test to prove her Native American ancestry. With this action, critics say, the possible 2020 Presidential candidate has played into the concept of “racial science”–validating the alleged link between blood and race, which The New York Times calls “a bedrock principle for white supremacists and others who believe in racial hierarchies.”
That’s not, I trust, the way most of us view genetics. We may remember how we were introduced to the subject in school: with Gregor Mendel and the 29,000 pea plants he cultivated that formed the foundation of the field. But even among the experts, “we never knew how complicated heredity is,” Hercher says. Single gene inheritance, such as blood type, is fairly straightforward and rare—as are diseases attributed to a single gene, the so-called “Mendelian diseases,” which include sickle cell disease, as well as cystic fibrosis, Huntington disease, muscular dystrophy, and a few others.
Most of genetics, Hercher stresses, is more multi-layered. Heredity, and the traits and illnesses that are in our DNA, involve the interaction of genes with both our external environment and the internal environment comprised of our hormones, metabolism, and other factors. So when we find out we have certain genes—and their variants and mutations—there’s no straight line to determining how our bodies will deal with their existence.
One important issue that stirs debates among geneticists involves ApoE4—the gene that denotes a higher risk for Alzheimer’s and carries both individual and societal implications—for care and economics—as our population ages. Approximately 25% of Caucasians carry this gene, but Hercher points out that an individual at somewhat increased risk may not develop the disease; while someone with decreased risk may still get it.
And currently, without a cure, that raises questions. “There’s a faction in the genetics counseling community that says we have no business giving out that information,” says Hercher. Indeed, when Matt Fender initially sought guidance from his primary care doctor, Hercher reported in her Times article, the doctor responded: “What the heck do we do about it, once we know, other than create high anxiety?” However, says Hercher, “a growing faction says that whether or not to provide the information is not really our call.” In other words, it’s the patient’s decision.
So if we’re deciding to search out our ancestry–or to be tested for a possible disease– the important thing for us, the consumer/patient, is to seek education before we even consider being tested.
How will we regard the potential results? Do we need the information to inform our choices about health decisions that must be made—before a pregnancy, for example, or to assess our odds of developing certain cancers?
On such matters, Hercher stresses, both factions in the genetics counseling community agree: if the information is to be given, good counseling should be involved to help patients think through the implications—and then to support them once they’ve decided whether or not to act on the findings.
What do you think? Have you had any experiences you’d like to share? Please enter them in the Comment box near the bottom of this post.
(To let me know your thoughts about this post, you can click on the stars below: from left to right, click star 1 for awful; star 5 for excellent. WordPress folks have the option to “like” this post further below. Thanks so much for your input.)