Direct to Consumer Genetic Testing: Think Before You Spit, 2017 Edition!

Posted on by Muin J Khoury, Director, Office of Public Health Genomics, Centers for Disease Control and Prevention

test tubes and DNAAs people have become more proactive in managing their health, personal genomic direct to consumer (DTC) testing has become more popular over the past decade. These tests allow consumers to access information about genetic predispositions and response to chemicals and medications without the involvement of healthcare providers.  With the expanding landscape of such testing, the need for provider education and public genetic literacy has become more important than ever.

Typically, these tests use DNA derived from saliva to measure hundreds of thousands of genetic variants and provide individualized reports on genetic predispositions to common conditions, such as Alzheimer’s disease, celiac disease and Parkinson’s disease. Some tests also include information on carrier state for rare genetic conditions such as hereditary hemochromatosis and hereditary thrombophilia.

Although personal genomic tests for disease susceptibilities could help to make decisions about lifestyle choices or inform discussions with providers, they are not diagnostic tests, and cannot be used alone for treatment decisions or other medical interventions (in contrast, for example, to BRCA gene testing for hereditary breast and ovarian cancer).

The pros and cons of personal genomic DTC tests have been discussed for years (see recent example.)  We have adopted a cautionary attitude about personal genomic tests. In 2011, we advised consumers to think critically about the health utility of these types of tests, as well as the potential harms and unnecessary follow-up health care costs that could result from testing. In our three-tiered evidence classification of genomic tests, we include personal genomic tests as “tier 3” tests. Such a rating implies that there is no evidence for clinical validity or utility of such applications in healthy individuals in the population. In 2009, on the basis of a scientific workshop, we called for additional research to evaluate the validity and utility of personal genomic tests to improve health and prevent disease. Over the past few years, some of that research has been conducted and published. For the most part, data on personal genomic testing have revealed little or no harms but also little or no health benefits. Also, evidence on the ability of genetic information to change health behavior has been lacking.

With improved technology and plummeting prices in the coming decade, we could see an expansion of DTC testing for personal genomic information. The content of information obtained from such testing will evolve. Nevertheless, both the general public and the health care provider community need to be aware of the potential utility and limitations of such tests. In a 2016 study, a survey of people who underwent personal genomic tests found that most of those tested who shared results with their health care providers were not satisfied by the reaction of their providers. Many providers questioned medical actionability of the test results and showed lack of engagement or interest. In a recent commentary in Nature, Dr Zak Kohane from Harvard University stated that when it comes to personal genomic tests, “we really have a perfect storm of insufficient data and insufficient competence.” Physicians aren’t yet prepared to handle genetic test results of this type and neither is the general public.

While evidence of utility of personal genomic information continues to be collected through ongoing research studies, it is important for professional societies, healthcare organizations, public health agencies and the private sector to improve the level of genomic health literacy of the public. We all need unbiased information to be empowered to make the most informed decisions about genomic and other tests for our own health. Our advice, in 2017, remains the same as in 2011, namely for consumers to think before they spit and rush to do DNA personal genomic testing (see our previous blogs: 2011, 2012 and 2016).

We have recently initiated a community conversation about the appropriate role of genetic screening in healthy adults (see our recent blog). We invite our readers to share their thoughts and opinions.

Posted on by Muin J Khoury, Director, Office of Public Health Genomics, Centers for Disease Control and PreventionTags ,

14 comments on “Direct to Consumer Genetic Testing: Think Before You Spit, 2017 Edition!”

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    Nice commentary – I am thankful for the specifics , Does anyone know where I might access a blank Personal record form template document to use ?

    Hi, thanks for your a great post that give everybody some important information. I think it is especially useful to me.

    Understanding your risks for chronic disease is an important element of prevention. Completing a health risk assessment that includes your health, lifestyle and family history information can provide you with the next level of knowledge before you plunge into the idea of genetic testing. Family Healthware is available online and was originally developed by the CDC.

    I think this is the early stages of the new medical era. although information is preliminar just knowing about yourself things you didn’t know before I think is amazing. I just had my test done this week and looking forward to the results.

    Informative. In this era of too much information sharing, it is good to be clear about what exactly you are asking for, expecting in return and who will have access. I am just considering testing for genealogical information, but this brought several issues to my attention that had not occurred to me. Always better to be well informed about all sides of an issue.

    I’m not sure how much I trust personal genomic DTC companies rigor in regards to testing. However, if someone does get this done they need to see a genetic specialist to discuss their test and the results. The average PCP does NOT have enough genetic education to be able to interpret the test results. My PCP thought my risk of having a child with Down’s Syndrome was extremely low due to my age. He didn’t understand enough about genetics to correctly access my health risk assessment based upon family health/medical history. My high school genetics from Canada turned out to be more genetic education then he received in medical school. I did see a genetic counselor and was informed that I was at higher risk for having a child with Down’s Syndrome. Interpreting genetic tests is a specialty.

    I agree with you. It’s not so much that the data is not correct as it is the lack of interpretability on behalf of the physicians. Raw data is good only if you can apply it to the situation and I don’t think the average family physician or specialist is capable of looking at the raw data knowing what they know about the patient and put two and two together without doing some deep pondering and they just don’t have the time for it.

    What people and the post doesn’t mention that as soon as you consult your physician or get a physician prescription, the test may become part of your medical record. To apply for life or long term care insurance, you need to give them access to your medical records. So medical records with all of HIPAA etc. is not so private. It is a big reason why I don’t want my genetic data in my records.

    I received health risk assessment information from a DTC several years ago and have found it quite useful. Knowing that I was at higher risk for 2DM, I have been more careful of weight and diet. Knowing that I was at higher risk for macular degeneration, I’ve not skipped eye examinations and won’t. Although not now needing prescription drugs, I’m glad to know something about my probable reactions to some of them. Certainly knowing one’s family history of health and disease is important, but lots of people have significant gaps in their histories. It’s good to have all the information you can get. Medical professionals will just have to be brought into the modern era and quickly and should not ignore or resent it when their patients are knowledgeable about genetics.

    Nice post! Thanks for giving the information about genetic testing, its very easy to understand and its very informative.

    I would like to know what CDC would recommend for the health testing like what company, what type of test that sort of thing.

    CDC does not issue recommendations on Direct-to-Consumer genetic testing. In addition, our office (OGPPH) is not aware of evidence-based guidelines from any other sources that recommend use of Direct-to-Consumer genetic testing. Since your question refers to health testing in general, you might also be interested in contacting CDC-INFO for assistance in finding relevant information beyond the realms of genomics and precision public health.

    I read that knowing your apo E gene can allow you to make changes to your diet and lifestyle accordingly . One diet fits all in the health food market is un practical

    Totally! But APOE is a big exception with quite a lot of information. For most genetics, scientists have studied risk for disease, not how to prevent it in a personalized way

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Page last reviewed: April 9, 2024
Page last updated: April 9, 2024