Family Health: The Truth About Mail-In DNA Tests

Mail-in DNA tests are becoming a lot more widespread.

Lots of Info and Some Confusion

If you're curious about where your ancestors came from or concerned about diseases you might be likely to get, mail-in DNA tests make it easy to get some answers. Dozens of companies offer them, and they can be done with a sample of your saliva or a swab of your cheek. The catch is, you may learn "facts" about yourself that aren't quite factual.

Mail-in DNA tests cannot tell you your risk of getting a disease.

Myth: Predict Chances of Disease

These tests look for information in your genes that shows you might be more likely to get a specific disease, such as Alzheimer's or cancer. But they can't tell if you'll end up getting it. They can't even really tell you your chances of it. Other things, like your lifestyle or habits, affect your risk of getting diseases, too.

DNA tests may give you information about some conditions but not all conditions.

Myth: Cover All Conditions

The field of genetics is growing quickly, but only so many tests are available. So while you may get information about certain conditions, you might not get any about a less common disease you're concerned about.

A DNA test can only tell you about your origins based on the samples they've collected from others who've taken the test.

Myth: Map Your Family Tree

Each company has its own database of samples from people who live in different areas of the world, and they match yours against the others in the database. So your results won't include everyone who's been tested -- they'll only include people who've been tested by the company you choose.

Siblings' DNA will differ based on what each child inherits from the parents.

Myth: Same Info for Siblings

Everyone gets 50% of their DNA from each parent, but what's in each half can be different. So it's totally possible that you got more of your mom's European DNA and your sister got more of her Asian DNA. Add your dad to the mix, and things get scrambled further. Just as siblings don't always look alike, their DNA might not look alike, either.

There's no strong evidence that DNA tests can tell you what kind of supplements to take.

Myth: Nutritional Needs

Some testing companies offer personalized advice on dietary supplements based on your test results. Some even try to sell them to you. But no studies show that genetic tests can give you useful information about those or dietary choices.

Genetic tests do not tell you how well you process environmental toxins.

Myth: Effects of Toxins

Not everyone who smokes gets cancer, and some DNA testing companies suggest that the reason for that is in your genes. It may be, at least in part, but there's no strong science that proves genetic tests can tell you how well your body handles certain things in the environment.

Genetic test results may be used by companies that sell life, disability, and long-term care insurance.

Myth: Insurance Rates

Laws are in place to protect you from being denied health insurance or charged more for it. But those laws don't apply to life insurance, disability insurance, or long-term care insurance. That means it's possible your genetic test results could be used by the companies that sell these types of insurance.

The FDA is coming up with guidelines for genetic tests.

Myth: Government Regulations

Most of these tests are made privately and can be sold to you without any proof that they work as advertised. That may soon change, though. The FDA is coming up with guidelines for genetic tests.

Look for a mail-in DNA test that is CLIA certified.

Myth: All Tests Are the Same

While no testing company can guarantee that the information it gives you is 100% accurate, some are better than others. If you decide to try at-home DNA testing, look for one that meets the U.S. standards called Clinical Laboratory Improvement Amendments (CLIA), and check to see if the tests have been approved by the FDA.

Make sure your mail-in DNA test results really are private.

Myth: Personal Info

Read the fine print. Most companies make an effort to keep personal data "private," but that can mean different things. Make sure you understand what data they're collecting and who will see it.

Mail-in genetic tests may reveal surprises like new relatives or disease information.

Myth: Harmless Fun

At-home DNA tests can be entertaining, even if they're not always accurate. But they can cause stress, too. Sometimes genetic tests reveal not-so-happy surprises, like a family member not being related to you or the possibility that you'll get a certain condition. You might talk with a genetic counselor before deciding whether to get tested. And if you decide to do it, the counselor can help you understand the results.

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REFERENCES:

  • Johns Hopkins Medicine: "Five Things to Know about Direct-to-Consumer Genetic Tests."
  • Federal Trade Commission: "Direct-to-Consumer Genetic Tests."
  • Moffitt Cancer Center: "Do DNA Kits Put Your Privacy on the Line?"
  • NIH Genetic Home Reference: "How Do I Choose a Genetic Testing Company?" "What Are the Benefits and Risks of Direct-to-Consumer Genetic Testing?" "What is Direct-to-Consumer Genetic Testing?" "What is Genetic Discrimination?"
  • NIH National Human Genome Research Institute: "Regulation of Genetic Tests."
  • The Tech Museum of Information (Stanford University): "Shouldn’t my sister and I have the same ancestry results for our DNA?"
  • Tufts Now: "Pulling Back the Curtain on DNA Ancestry Tests."
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