A short primer on mail-order DNA kits
Companies have dramatically increased the reliability and range of at-home genetic health testing while reducing the price. But if we are honestly concerned and want to be informed about our health, what should we do?
At-home ancestry and genetic health products have become increasingly popular, making it easier for more people to identify their ancestral history and risks for genetic disorders with sometimes just a swab of the cheek.
But is it that simple?
Advertisements for companies such as 23andMe, Gene by Gene and MapMyGenome, to name a few, market the benefits of knowing one’s genetic makeup as not only a curiosity to be satisfied but a legitimate attempt to address significant future health concerns.
For $199, 23andMe will provide “75-plus online reports on your ancestry, traits and health — and more” as the website suggests (the genetic health test cannot be purchased separate from the ancestry test). If you prefer your whole genome sequenced, Gene by Gene has you covered — at just $2,495 per sample. Or you might be able to find a Groupon-like deal for around $50, especially around a holiday.
The accuracy, reliability and security of these tests may steer the discussion into the murky waters of ethnic identity and parental legitimacy. Have you seen the commercial with the actor who exchanged his “lederhosen for a kilt?” No matter what mail-order genetic test may suggest, if my grandmother served schnitzel every Sunday and I walked in with haggis, I know I would be wearing one of those entrees (probably both).
To borrow an ominous line from another advertisement, some people want to know “what’s coming down the pipe.” Those of us who want to be educated and informed about ourselves must balance the trade of personal information (and nearly $200) with peace-of-mind.
For medical professionals, whether to use at-home — also known as direct-to-consumer, or DTC — genetic testing kits fall into the “buyer beware” category.
These tests have “moved beyond recreational use for ancestry testing and the like,” says Tiffany Lewis, a genetic counselor with Virginia Oncological Associates. “Before purchasing any DTC test, it is important to understand what information you will receive and what you will not.”
In February, the Federal Trade Commission, citing the Food and Drug Administration and the Centers for Disease Control, admitted that direct-to-consumer, or DTC, genetic tests have some positives, like making it easier for people to get involved in their own genetic health. But the report also said that some of the tests lacked scientific validity, while “others provide results that are meaningful only in the context of a full medical evaluation.”
The bottom line: Results from a DTC test could mean a trip to the doctor or genetic counselor to figure things out. A positive test result may indicate an increase in the chance of a specific health issue, but it is far from a guarantee. Likewise, a negative result does not guarantee immunity.
Still, curiosity over finding out one’s genetic background holds a big allure for many. The number of people who have had their DNA analyzed with at-home kits more than doubled last year and now exceeds 12 million, according to industry estimates.
Initially, Jerilyn Buggé, a middle school teacher in Washington, D.C., was apprehensive. “I said, ‘I’m not doing that! I’m not putting my DNA out there for the government.’ At first, there was no way … I mean, you have Big Brother everywhere.”
But Buggé’s curiosity — to find out not only her family’s geographic ancestry but also to know if she was at risk for disorders prevalent in her family — outweighed the risk. So she asked for a 23andMe kit for Christmas. “I was interested in late-onset Alzheimer’s disease, because it runs in my family,” she says.
For women, however, ancestry test results will be incomplete alone. Women do not have a Y chromosome, which is used to define paternal ancestry. Although women inherit roughly half their DNA makeup from their fathers, women who take an ancestry test will receive a report of their maternal ancestry, but since there is no Y chromosome, the test cannot differentiate the maternal genes from the paternal genes of the family. On their website, 23andMe asks women to connect their results to DNA results from either the biological father or full brother to get the complete family lineage.
Sheldon Krimsky, a Tufts University professor who wrote “Genetic Justice” and chairs the Council for Responsible Genetics, says it’s hard to know just how accurate the tests are when it comes to ethnicity and genealogy. The companies don’t share their data, he says, so their methods can’t be validated by independent scientists. Some people, in fact, have sent their DNA to several different companies and gotten different results.
Each company uses its own proprietary database of DNA samples and looks at certain genetic variations as the basis for evaluating individuals. “The results are in no way definitive,” Krimsky said in an article on the Tufts website. “Instead each company uses common genetic variations as the basis for saying the probability is that 50 percent of your DNA is, for example, from North Europe and 30 percent is from Asia, based on how it compares to the information in its database.”
Basically, Krimsky says, “you have to look at the percentages you receive back with skepticism.”
Buggé’s test results were in line with her assumptions, so she did not feel the need to contact her doctor. “But that’s what my daughter did,” she says. “Her report showed a higher risk for celiac disease, and she knew her father had celiac disease, so she went to the doctor and asked to be tested because [of the results].”
The DNA kits generate a lot of information, which Buggé discovered after getting first one set of results, and then updates. However, not all of the results are translated for the average consumer, and it is easy to be overwhelmed without a strong background in genetics or a guide to help sift through the results for meaning.
“Genetic counselors can help navigate the genetic testing process, interpret complex scientific data, and serve as an advocate for the patient and their family,” says Lewis, who works with those affected by or at-risk for genetic conditions. “Individuals should consider contacting a genetic counselor if they have a family history of a health condition they suspect may be genetic and are considering genetic testing for themselves.”
Lewis is a strong advocate for genetic testing, especially when used as a tool to confirm a diagnosis of a genetic condition, guide medical management, or screen and test other at-risk relatives.
“Genetic testing has helped many patients and families find answers to previously unexplainable symptoms” she adds. “In the oncology (cancer) setting, in some cases, genetic testing has allowed patients to better understand the lifetime risk for cancer and empower them to make more informed decisions regarding cancer screening and lifestyle choices.”
But the shortcomings of direct-to-consumer tests are just as extensive. In March, for example, the FDA highlighted a DTC report on three specific gene mutations common in breast cancer patients. Yet according to Lewis, those mutations, while seen in people of Ashkenazi Jewish ancestry, aren’t commonly seen in other populations.
“There are thousands of different [gene] variants this test will not detect,” says Lewis, who points to the bigger problem: “Similarly, while [the gene variants] account for [approximately 50 percent] of hereditary breast cancer, there are other breast cancer genes this test will not analyze. Therefore, a negative result for this particular DTC test does not rule out the possibility of hereditary breast cancer in a family.”
In other words, if someone misreads the fine print of a DTC tests and receives a negative test result, it’s easy to make the jump that this person does not have any increased risk for a genetic disorder when, in fact, this is not the case.
“Anyone ordering a DTC test should always discuss the results with their healthcare provider,” says Lewis. “Any information received from DTC testing should be discussed in the context of the patient’s personal and family history.”
What about the identifiable data that consumers are volunteering (nay, paying) to companies to house their genetic information? Lewis advocates discretion and due diligence. “It is important to consider and understand the specific company’s privacy clause,” she says. “How do they protect your data, are they selling it to a third party? In some cases, your de-identified data is used for research unless you specifically opt out. In addition, DTC companies could be subpoenaed to release your DNA.”
In fact, the Washington Post reported in April that California police cracked a 42-year-old cold case when they identified “Golden State Killer” as Joseph James DeAngelo. Police found him by comparing DNA evidence in the case with databases at GEDmatch, a popular (and free) genealogy website. According to the article, DeAngelo never used the service, but a member of his extended family did, “and that person’s DNA partially matched evidence related to the serial killer.”
While few would argue against the legitimate use of genetic information in the name of justice, privacy advocates raise concerns over the abuse of such powers. The Federal Trade Commission recommends reading the privacy policy with each kit, which should say how the company will use your information, how it will secure it and whether it will share your information with third parties.
So, what should the average person do when considering these DTC tests? Are they worth it? Well, maybe. But if you’re truly concerned about finding out if you’re susceptible to a certain disease, the genetic health tests ordered and conducted by medical professionals are better tailored to individual’s specific genetic makeup.