The rapidly evolving world of DNA testing offers a chance to unravel mysteries about our family histories as well as our current and future health concerns. An idea that only decades ago provided the riveting plot lines of far-fetched science fiction movies now exists as a reality at our fingertips, or perhaps more accurately, in our saliva sample.
Have you ever wondered:
“At home DNA tests can be hugely beneficial to consumers, depending on what they're looking for,” says genealogist Marc McDermott. “Most people will test to get an ethnicity report, but many people also test because they were adopted and want to find their biological parents. More and more people are also testing today for the health reports which can be great to identify potential concerns to discuss with their doctor.”
Sajung Yun, PhD, is the associate professor of bioinformatics for genome analysis at Johns Hopkins University and chief executive officer of PredictivCare. "At-home DNA tests can help people by making them aware of current and potential health problems," says Yun. "They then have the opportunity to practice preventive measures that could prevent or delay the onset of disease."
In order to help you find the best DNA test for your interests, Health's editorial team conducted extensive research on a dozen of the most popular companies providing at-home DNA test kits. We consulted experts in the field of genealogy, genetic testing, and genetic counseling to define the risks and benefits of DNA testing for consumers and read hundreds of customer reviews.
Our team examined the science and successes behind each company’s claims, and we became customers ourselves to gain insight into the process of purchasing a DNA test kit.
The best DNA testing kits on the market today, according to editors:
While the process may vary somewhat by company, here’s what you can expect:
Results include: Ethnicity estimate; DNA matching for relatives
The AncestryDNA test, which offers insight into origins and ethnicity as well as DNA matches, is our top pick for those who desire to fill in the blank spaces of their family tree. AncestryDNA is better equipped than its competitors to estimate ethnicity, since the accuracy of this estimate increases as the number of DNA samples available for comparison increases.
While the company doesn’t routinely divulge the size of its database, some estimates place this figure around 18 million DNA samples, far surpassing the competition. This larger database also gives you a greater chance of connecting with relatives through DNA matching. You’ll be able to connect with others in the database who have similar DNA to yours, and AncestryDNA will tell you their genetic relationship to you.
AncestryDNA’s StoryScout feature helps you collect artifacts such as marriage certificates and passport photos to give life to the story of your family members. You can trace your ancestors’ journeys over time to see the geographic locations they traveled. Your results are a great way to start your family history research or to add depth to research you’ve already gathered.
Genetic data is constantly evolving, and as information changes, AncestryDNA will continue to update your profile, giving you more specific data as it becomes available.
Time to results: Six to eight weeks
Information updates: Yes
Read our in-depth comparison of 23andMe vs. Ancestry.
Results include: Ethnicity estimate; DNA matching for relatives; Health predisposition reports; Carrier status reports; Wellness reports; Personal traits reports
23andMe offers a bundled service that includes ancestry and health information. Along with an ethnicity estimate to show you the people groups making up your genetic history, you’ll be able to map the movement of your ancestors from place to place and find relatives through DNA matching. With your genetic information, 23andMe will help you build your family tree as well.
23andMe’s health report shows your genetic predisposition to develop certain diseases, your carrier status for inherited diseases that may be passed on to your children, information about personal traits such as eye color and facial features, and wellness markers such as caffeine consumption and lactose digestion.
Our editors chose 23andMe as the top choice for health testing primarily due to the breadth of disease states covered by its test. Common illnesses that affect a large part of the population such as Type II Diabetes and age-related macular degeneration are addressed, and these are not offered by competitors such as AncestryHealth. Furthermore, 23andMe reports your carrier status for a long list of diseases—another feature not offered by competitors but likely to provide great benefit to customers.
With 23andMe, you have the unique ability to test for genetic markers associated with late-onset Alzheimer’s disease and Parkinson’s disease. This can be controversial for some people—do you really want to know if you’re likely to develop an unpreventable, incurable disease? You can opt out if you choose, but many people desire that information.
One important caveat to consider when choosing 23andMe’s health test is its method of evaluating your DNA. The process, called microarray technology, allows comparison of your DNA against a few known variants associated with a disease, but they don’t test for every variant that could cause the disease. Next-generation sequencing, used by AncestryHealth, is able to analyze more genetic variants, giving you a better understanding of whether you’re actually at risk for this disease.
“Microarray technology is generally known to be less accurate than next-generation sequencing,” says Yun. This is especially important for diseases such as breast cancer and colon cancer where several genes and their variants are at play. With either method it’s possible to get a false negative result (meaning, you think you’re not at risk for the disease, but you are and the test wasn’t able to show it), but it’s more likely to occur with 23andMe’s method than with AncestryDNA.
Time to results: Two to three weeks
Information updates: Yes
Read our full review of 23andMe here.
Results include: Ethnicity estimate; Health predisposition reports; Carrier status reports; Wellness reports; Personal traits reports; Pharmacological compatibility
TellmeGen offers an ancestry plus health test that gives over 390 results. While the ancestry results aren’t as robust as competitors’, the health component may be the most comprehensive at-home DNA test you’ll find. You’ll receive information about your genetic predisposition to 100 diseases, carrier status for 88 inherited disorders, 150 characteristics of medication compatibility, and more than 50 personal traits. These personal traits are more meaningful than other tests that give information on hair growth or eye color; this test looks at likelihood of alcohol dependency, thyroid function, or preterm birth.
With TellmeGen, you’ll have access to a free medical forum where you can share your thoughts and ask questions of other users as well as the medical team. For an additional fee, you can request a consultation with a physician, genetic counselor, or nutritionist. Your results will be continually updated as new genetic science becomes available.
TellmeGen uses microarray technology (similar to 23andMe), which tests your DNA for certain variants of a gene known to be associated with a disease. The test doesn’t give you information on every possible genetic variant that could cause the disease, only the most common. It is possible that you could have a genetic variant increasing your likelihood for the disease, even if the test report is negative.
Time to results: Four to six weeks
Information updates: Yes
Before you take a DNA test, ask yourself whether you really want to know some of the information that could become available to you.
People often find surprising information when they dig into their family history—information that affects not only themselves but their parents, siblings, or children. You may find a connection to a relative you didn’t know existed or you could find that your genetic information is not linked to someone you thought was a blood relative. These could become issues you and your family grapple with for years to come.
Do you want to know if you’re predisposed to an incurable disease such as Alzheimer’s or Parkinson’s, or would you rather only know about diseases you can take action to prevent, such as Type II diabetes or high cholesterol? Depending on the type of test you choose, you may have to consider these questions as well, and your answer may affect your loved ones, too.
Make sure you’re prepared for surprises and be certain you want to know the answers your test provides.
While most people seem to be pleased and intrigued after receiving their results, there is a common theme among customer complaints. These issues often center on the accuracy of ethnicity estimates (the part of your results that tell you you’re 25% Korean or 75% Ashkenazi Jewish). This may happen more often when people of Asian, African, or American ancestry trace their roots.
When uncovering family origins, the company may compare your DNA to others throughout the world to identify similarities and divergences. Many of the companies offering DNA testing began with most of their DNA data coming from European origins, so more information is available for those with European backgrounds. However, as more people from diverse backgrounds continue to undergo DNA testing, more information becomes available to make better estimations of your ethnic roots.
Furthermore, unraveling ancestral history requires more than DNA. Genealogists use documentation such as birth and death records, marriage certificates, ship manifests, and other clues from the time period to piece together a family’s story. However, during dark periods of our collective history, such as the African slave trade or the displacement of Native Americans, these artifacts may never have existed or could have been destroyed, making it difficult for descendants of these groups to find information.
There are also limitations on what a DNA test can tell you about your health, especially when obtained outside the traditional framework of a physician-patient relationship.
In many cases, multiple genes play a role in developing disease, many variations of those genes can occur, and a multitude of lifestyle and environmental factors affect whether a person will have the illness or not. DNA testing alone cannot capture your true risk of disease in this scenario.
Most of the at-home DNA tests are not testing your entire genome; they are looking at small snippets of DNA associated with specific health issues and reporting certain findings. For instance, if the test examines a gene known to be associated with breast cancer, the findings may tell you whether you have one of the common cancer-causing variations of that gene.
However, the test may not examine all 40 of the possible variants associated with that cancer—perhaps it only considers the 10 most common. You may think you’ve received an all clear because your test said you didn’t have one of the most common cancer-causing variants. In reality, you could still have a genetic marker for cancer that was not reported by that particular test.
If you’re using an at-home health DNA test to satisfy your curiosity, to help inform you about how to make better lifestyle choices, or to answer some interesting but not life-altering questions about yourself (e.g., is there a genetic reason for my distaste for cilantro?), these tests can be a place to start. But you must know that they can only give you part of the picture.
If your concerns are more serious (e.g., will I get breast cancer in my thirties like my mother did?), you need to know these results are not going to give you all the answers you’re looking for.
For a full understanding of your genetic risk of disease, work together with a physician and a genetic counselor. Gillian Hooker, PhD, is adjunct professor of genetic medicine at the Vanderbilt University Medical Center in Nashville, Tennessee, and president of the National Society of Genetic Counselors.
“Genetic counselors empower patients and their families with information, guidance and emotional support to help them understand their family history, evaluate their genetic testing options and make informed choices based on their test results,” says Hooker. “Genetic counselors can connect you to the information and resources you need to make informed choices about how to manage your risk of disease. They may be able to help identify the right tests to provide further information and in some cases, they may be able to help you avoid going down paths that aren't useful for your health or the health of your family.”
If you’re interested in purchasing a DNA test, you’ll have to decide whether you trust the company with your sensitive information.
The privacy safeguards of the Health Insurance Portability Act (HIPAA) that requires doctors, hospitals, and insurance companies to protect your personal health information does not extend to most DNA testing companies. Without legislation that protects the privacy of your genetic information, questions about how your information will be used and shared must be answered by the company’s privacy statement.
Read the privacy practices of the company carefully to be sure you know how your genetic information will be shared. Look for transparency in how your information will be used and requests for your consent to use it as well as the authority to request destruction of your data.
A DNA test can be a great way to indulge your curiosity about both your family history and your health. It’s important to keep in mind, though, that gene science is constantly evolving, and there can be variability in estimates of your ethnicity and predictions about your likelihood of illness. When it comes to understanding your genetic predisposition for serious diseases, don’t go it alone. Ask your doctor or seek help from a genetic counselor to get a true understanding of your risk of developing a disease.
Dr. Courtney Schmidt is a clinical consultant pharmacist and geriatric care expert. Since completing her Pharm.D. at the University of Florida, Dr. Schmidt has worked in multiple clinical settings and has served as an Adjunct Professor at the University of Central Florida.