With such easy-to-use DNA tests now readily available for the public, everyone is wishing to uncover their ancestral past. Particularly during the holiday season, sales of DNA kits that can reveal individuals’ ethnic background and genetic health risks are in the millions. Companies such as 23andMe and Ancestry.com are leading the charge; suddenly, information about your great-great-great grandparents is only a test tube of spit away. Or, you can discover a long-lost relative who is still alive. The opportunities seem endless.

However, despite their incredible popularity, some scientists, researchers and critics are concerned about the potential serious risks that these DNA tests hold. Issues of privacy and accuracy have come up time and time again in the news. So, it is probably best to understand all of the risks before buying a DNA test.

Find your ancestors, lose your privacy

Have you ever taken the time to think about the privacy risks of handing a company a tube of your DNA? Earlier this year, the Federal Trade Commission issued a warning to consumers about the privacy implications of DNA test kits. Specifically, they stated, “that tiny sample [of DNA] can disclose the biological building blocks of what makes you you.” When you spit into that tube, you are providing companies with a wealth of information about yourself. And the issue is that it is not always clear what these companies do with that personal information. Being such a new and fast-growing industry, regulations are often formed after-the-fact. Therefore, protection of genetic databases and enforcement of bona fide privacy policies for DNA test firms are still in their developmental stages. Therefore, the question worth asking yourself is: is your profile being shared with other organizations, research institutions, or even advertising companies? Do you technically own that DNA once you send it to a DNA testing firm?

These are all good questions to ask yourself before blindly ordering a DNA test and clicking the “I Accept” button at the bottom of the Terms and Conditions page. When it comes to sharing your genetic makeup, it may be best to take that extra 20 minutes to read through all of the information provided. And, if you are confused about anything, you should take the time to do additional research or reach out the company to fully understand their practices. Maybe there are more protective options offered by the genetics company that you were not aware of. With these extra details, you can form a clear picture of all of the possible risks before packing up your DNA and sending it off in the mail.

How well do these tests actually work?

Back in 2013, 23andMe got into a lot of trouble with the Food and Drug Administration. Specifically, the FDA was not a fan of how they were administering genetic tests for disease risks, such as Parkinson’s, Alzheimer’s, and cystic fibrosis. In their 2013 statement, the FDA noted that 23andMe was marketing disease risk tests without the clearance or approval of the FDA and were in direct violation of the Federal Food, Drug and Cosmetic Act. Without the FDA stamp of approval, 23andMe was providing individuals with potentially false genetic tests that could cause people to undergo surgery, intensive screening, or other preventative measure unnecessarily. Therefore, the FDA ordered them to stop selling genetic risk tests to costumers.

Since that time, 23andMe has been approved to re-start their marketing of disease risk genetic tests. However, this story still contains an important message: genetic tests can be inaccurate. Additionally, some people may not be fully aware of the intensity and impact of these disease risk tests. Before the growth of DNA testing companies, most individuals received genetic counseling before receiving such tests. Nowadays, people can get information about their genetic mutations and risks for serious diseases at a relatively low cost. Depending on the person, this information may not be received well. For that reason, it is key to know what you are ordering beforehand and make sure you and your family are well prepared.

In addition to disease risk tests, there are still some kinks in ancestral tests. If you’ve ever taken multiple DNA ancestry tests, you’d know that they don’t come back with the exact same results. Each company that offer DNA tests, including 23andMe and Ancestry.com, have their own DNA databases with different ancestry informative markers. These ancestry informative markers are pulled from current populations in Asia, Europe, Africa and the Americas. Scientists search for single nucleotide polymorphisms (SNPs), or genetic variations within the gene, in order to evaluate the ancestral history of individuals. SNPs are important because they have different frequencies across separate populations. However, the SNPs are compared only with those most frequently associated with geographical populations within the company’s individual database. Therefore, these tests are not entirely accurate and are only representing a probability that you are from Africa, or Northern Europe, or Asia.

It is also key to note that the majority of your DNA is actually not examined in these tests. Although you contain millions of SNPs, the DNA databases used only use 100 – 300 ancestry informative markers. So, if your ancestry test tells you that you are 80% African, that is really only a representation of a small portion of your SNPs.

The more information, the better

Even with these possible issues, people should not be discouraged from buying a DNA test. Like any medical information, it is always best to do your research beforehand and chose the best company for the job. Just as importantly, all DNA results should be taken with a healthy skepticism. DNA testing is still an evolving field, and no scientific test is 100% accurate. If you wish to get a disease risk test, consult with your doctor either beforehand or afterwards. If you and your family are interested in discovering your ancestral history, remember that your DNA is an extremely complicated set of genes that can’t possibly be simplified to one test. But that doesn’t mean that you can’t uncover fascinating pieces of your history that are interesting, fun, and add to your understanding of who you are.

Nikki Collins

Nikki Collins is a freelance writer and scientist. Her scientific experience ranges from academic research at IU School of Medicine to the public health arena working in institutions such as Centers for Disease Control and Prevention (CDC). When not in a lab or at a computer, she enjoys almost anything outdoors, dance, and reading.