By Serena Talcott Baughman, MS, CGC; Certified Genetic Counselor, Oregon Reproductive Medicine
6 things genetic counselors want you to know before spitting in the tube
Five years ago, when I was in graduate school for genetic counseling, I wrote my ethics thesis on direct-to-consumer (DTC) genetic testing companies. While we were told not to choose a topic that was personal, I did it anyway. My mother-in-law had just informed my husband and me that she was going to use 23andMe, an at-home DNA test kit, “to find out if she would get Alzheimer’s disease like her mother did.” She planned to base the financial decisions of her retirement on this test result – if she got a negative result, she would be so confident in it that she would not set money aside for long-term Alzheimer’s care. Her plan made sense on the surface, but the reality was much more complicated.
Since then, my experience with these types of tests has become less personal and more clinical as increasing numbers of patients come to genetic counselors with their own DTC results: it is estimated that over 12 million Americans have some type of personal genetic data. There are more than 30 different companies, like 23andMe, AncestryDNA, and Living DNA, offering DTC tests using genome-wide technologies to calculate risk for a number of common diseases without going through a medical practitioner––thus the “direct to consumer” label. Most of these companies use a genetic profile or “genome scan” which involves testing thousands to millions of genetic variants called single nucleotide polymorphisms (SNPs) across a person’s genome. Based on these results, consumers are given information about their ancestry, physical traits like hair type and earwax, and risks of developing certain diseases like breast cancer, celiac disease, Parkinson’s disease, and Alzheimer’s disease.
Given the popularity of this type of testing, people clearly desire to know what information is hidden in their genes. But there are some important things to think about before spitting in the tube:
1. Are the results valid?
There is no mechanism to ensure that DTC tests are supported by good science before they are marketed. Therefore, the validity of the test results is unknown. Multiple studies have shown that the same DNA sample can be analyzed by multiple DTC labs and result in very different risk estimates for a disease.
The accuracy of the “raw data” (the actual DNA sequence that is revealed through the test) is actually quite high (99.7%), so the testing methodology itself is likely not the issue in most cases. However, the predictions given to people about their risk for diseases based on this raw data vary widely from lab to lab. There are many reasons for this, but the bottom line is the risks may not be accurate.
In the medical field, we talk a lot about whether a lab is “CLIA or CAP certified.” CLIA stands for Clinical Laboratory Improvement Amendments and CAP stands for College of American Pathologists. Even if a lab is CLIA or CAP certified, they do not have to demonstrate the clinical validity of the tests they provide, meaning they don’t have to prove that the results generated by their test have accurate, actionable information that can inform patient care. Because of this lack of oversight, DTC testing has the potential to cause unnecessary anxiety and fear with a positive result or an unwarranted sense of security with a negative result.
You are likely familiar with the federal Food and Drug Administration (FDA) and its role in protecting the public by ensuring the safety, efficacy, and security of drugs, medical devices, and medical tests. Many of my patients bring up the recent news that the FDA has––“finally!” ––approved 23andMe to provide results for a hereditary breast and ovarian cancer gene, BRCA. What they don’t understand, though, is that the 23andMe test is only looking at three out of over 1,000 possible mutations in the BRCA1 and BRCA2 genes. What’s more, the three mutations being analyzed are most common in people of Ashkenazi Jewish descent. The harm in this is that people who get a negative result may believe that this has reduced their risk of having a BRCA mutation, when in fact that is ONLY true if they are Ashkenazi Jewish.
A recent study showed that a whopping 40% of raw data results were false-positives when confirmed through clinical (ordered by a medical provider) testing. This means that a significant number of patients are getting false-positive and potentially scary results before eventually learning (IF they do follow-up testing through their doctor or a genetic counselor) that they do not, in fact, have these genetic variants. Emotionally, such patients may experience weeks or months of anxiety while they wait for results of retesting and hope for reassurance. Logistically, these patients are usually on their own to find medical providers who can help––and often they end up paying for a second round of testing they probably didn’t anticipate.
2. What IS the risk?
It is also important to understand that many of the genetic variants tested are actually only weak predictors of a trait or disease. There may be no harm in learning that you are “at risk” of the bitterness gene influencing how brussel sprouts taste. But if results show an elevated risk for macular degeneration or celiac disease, many consumers will take matters into their own hands and take supplements or change their diet. Consumers tend to believe that results are definitive, diagnostic and reminiscent of their prior medical experiences – you will or will not get Alzheimer’s disease.
The fine print of 23andMe’s website states that the results may be able to tell you that you have genetic variants that may increase your risk of developing a particular condition; and that they cannot tell you whether you actually have a specific disease, or whether you will develop a specific disease in the future. However, the general public is not typically well-versed in assessment or understanding of risk. Even as a genetic counselor, I find the concept of risk to be complex. It is not always easy to understand, let alone explain. Leaving consumers alone to decipher their futures based on their SNPs is a dangerous idea when they are not likely to understand the limitations of the information.
3. You may learn more than you expected
DTC genetic testing companies are approved to report out ancestry, trait, and some health information, but what many people don’t know is that they can also access files of their raw genetic data. Up to 62% of consumers use third-party applications to interpret the raw data and health information not included in companies’ reports. Through examination of this extra data, one of my patients learned that he was a carrier of cystic fibrosis; another learned that he had a cancer gene mutation (and a significantly increased risk for certain types of cancer). Both later learned that these were false-positive results. There are other, more alarming examples where consumers used their DTC results to make significant life and medical decisions when the findings were ultimately not confirmed through clinical, validated testing.
4. Are you emotionally prepared for the results?
Genetic testing is different from routine medical testing. First, a perfectly healthy person is often being tested – and people are often not as prepared to discover that they are at risk for disease when they didn’t present to their doctor with a concern. Second, genetic results typically affect an entire family. While we all know that genes are passed down from one generation to another and are therefore shared by family members, we don’t always understand how our own testing can expose things for our relatives.
Traditionally, a main component of a pre-test genetic counseling session is an assessment of the emotional health and support system not just of the patient but the larger family as well. Genetic counselors do not engage in these conversations to discourage patients from learning their genetic information. Rather, they want to prepare people for the potential consequences of the test results and arm them with some coping strategies. It is often encouraged that families engage in larger conversations about genetic testing so that everyone is aware of the impact and utility of the results. When this isn’t done, the impact on a patient and the ripple effect on a family can be devastating.
5. How do DTC tests affect the healthcare system?
In the early days of DTC testing, it was predicted that the separation of information-giving from the clinical setting could result in an extra burden falling on health services, as consumers bring their results to doctors who are not prepared to understand or explain this type of report.
I remember the story of the first patient referred to a medical clinic for counseling on her DTC results. A decade later, the genetic counseling community is still talking about the burden of extensive planning and research necessary to provide adequate support and information. It can be difficult to convince patients that their personally-prescribed care is not warranted or healthy. Even more significant is how difficult it can be to convince patients that their results could be false.
When there is inadequate pre-test counseling and post-results support, patients are less likely to understand that genetic information is limited and what we understand to be the meaning of a variant today may change in the future. They are also less likely to accept that many diseases are caused by a combination of genetics and the environment. But without other crucial factors like diet, exercise, and lifestyle being considered in their analysis, their risk estimates are likely inaccurate. The resulting discussions are often long and frustrating for both patients and providers, leading to a significant burden on an already overloaded health care system with limited resources.
The intention of DTC testing companies is (perhaps arguably) good. The model is a perfect example of personalized medicine, intended to empower patients and inform providers. But the reality of how the information is used has unintentionally led to scenarios where people are taking their futures and medical care into their own hands without the input of trained professionals.
When my mother-in-law called to share her excitement that her DTC test results would soon be in, I don’t think she expected my hesitation. While I now understand more about the limitations of DTC tests and could probably handle knowing her results, at that moment I was scared. She was focused on only one result––Alzheimer’s disease––and failed to recognize the larger implications of getting results related to other diseases.
6. Connect with a Genetic Counselor
What started as a personal story (don’t tell my ethics professor) is now supported by my professional training and clinical experience as a board-certified genetic counselor. It is a story told again and again by genetic counselors in the field––we are concerned about the actual or potential negative impact of DTC testing on individuals, their families, medical providers, and the health care system.
In fact, professional groups like the American College of Medical Geneticists recommend that genetic testing should be accessed solely through healthcare services and professionals. That said, DTC testing is not going away.
Before you consider ordering your genetic information from a DTC company, you can connect with a genetic counselor in your area through the National Society of Genetic Counselors (NSGC) or contact us at firstname.lastname@example.org and we would be happy to continue the conversation.
It is very likely that we could help guide you to a better test with a similar cost that would give you results that are more valid. Unless, of course, all you really want to know is if your hair is curly and in that case might we recommend…. a mirror?
Featured Image: DNA Self-Collection Kit by Pelle Sten is licensed under CC BY 2.0