Assuming You Want to Know, Genetic Tests Are No Crystal Ball

23andMe's DNA testing kit. (Photo by 23andMe)

Ever since our parents died, my brothers and I have invented our own ways to spend special occasions. Sometimes we take trips at Christmas, as this seems like a better gift than anything else we could buy.

Last Christmas, we went to California’s Big Sur, a coastal paradise a couple hours south of San Francisco. We ate lavishly, hiked lazily and had a small gift exchange. My older brother’s present, however, surprised us: genetic testing kits.

These direct-to-consumer kits have drawn withering criticism since 2006, when the U.S. Government Accountability Office found that the test firms make medically unproven predictions and provide results so ambiguous that they are meaningless.

All the same, the home test kits, by promising a crystal ball into a person’s medical future, have tantalized many consumers. The Food and Drug Administration estimates that 150,000 to 200,000 have been sold in this country.

Given my family’s sad medical history, I felt some of the allure. My father was a kind man but also an alcoholic who drank heavily every night, although he somehow survived to age 83 before dying of liver cancer.

My mother, who was much younger, succumbed to leukemia at 67, a year after getting her grim diagnosis.

Those memories floated in the back of my mind as I looked over my $199 kit that promised to help me “discover risk factors for 97 diseases,though I was plenty skeptical.

So what if it showed a genetic predisposition to a disease? Even if you assume that good science was used to produce the test results – a dicey proposition – that’s no guarantee of anything. Scientists still don’t know enough about the complex interplay between genetic variations and an individual’s existing health conditions, environmental exposures and factors such as diet and fitness to make accurate medical predictions.

Still, I obediently followed the directions, spitting into a small, plastic tube, sealing it in an envelope, dropping it in a mailbox. I would have to wait six to eight weeks for the results. In the meantime, I began to do some research.

DNA testing of saliva sample begins with consumer spitting into a tube. (Photo by 23andMe)

I learned that the U.S. Government Accountability Office had conducted a pair of what essentially were sting operations against the direct-to-consumer genetic test industry, first in 2006 and then again last year. The industry came out of it looking ugly each time.

In the 2010 investigation, GAO staffers sent the same DNA samples to each of four companies, and wound up receiving wildly varying results. In one case, a  DNA donor was declared by one company to be at below-average risk of getting prostate cancer and hypertension, while other test kit companies evaluating the same DNA sample alternately found the donor to be at average or above-average risk.

The GAO investigators also discovered that some of the kit companies were making bogus pitches to try to peddle dietary supplements, including claiming that they could use a consumer’s DNA to create personalized supplements to cure diseases.

Aside from the slippery evaluations and shoddy marketing practices, there also is the question of whether consumers – even those lucky enough to buy kits from above-board companies – are up to the challenge of interpreting the results. Just last month, following two days of hearings on consumer genetic tests by an expert panel, a Food and Drug Administration official said the agency might require some of the evaluations to be ordered or interpreted by a doctor.

The FDA also moved to rein in genetic test companies by putting them on notice last year that their products appear to be medical devices and, as such, the agency must approve them or be given justification as to why they don’t require a regulatory review. The agency still hasn’t taken any tests off the market, however.

While the agency decides how firmly it will regulate the genetic test companies, people like my brothers and me still are sizing up the results ourselves.

When my results were ready, I was notified via email by 23andMe, the Google-backed enterprise my brother purchased our kits from,  and one of various test companies in talks with the FDA about how to comply with the agency’s requirements. To view my disease predictions, all I had to do was log onto their website.

All in all, the test gave me neither the sense of false assurance nor the unnecessary anxiety that federal authorities warn about.

The results revealed I was at higher-than-average risk for Type 2 Diabetes and Age-related Macular Degeneration. (In other words, I have a better-than-average shot of going blind in my old age.)

The test also explored a growing branch of DNA testing – pharmacogenomics – assessing a patient’s likely response to certain drugs.  According to the test results, I have an increased sensitivity to Warfarin, a blood thinner, but no strong susceptibility to becoming addicted to heroin. Good to know.

I was rated as low risk for melanoma and breast cancer. That would be nice news but, given the history of those conditions in my family, I couldn’t take those readings seriously. 

My main frustration with the test was that the results were too wishy-washy.

23andMe uses a star rating system. According to Joanna Mountain, senior director of research at the company, four stars indicates that there are at least two independent studies linking a person’s genetic variation to a disease.

But two or three stars means that, essentially, researchers are on the fence. And, in my case, that fuzzy category accounted for 69 out of the kit’s 97 predictions and 11 out of the 19 drug response forecasts, including my likelihood of heroin addiction. 

Perhaps what’s needed, rather than putting these tests into the hands of doctors and geneticists, is some simple transparency about what the evaluations can and cannot do.

Shortcomings — such as the fact that too little genetic information has been collected on African Americans, Asians and other minorities to put their results in context — should be plainly stated on the package.

I discussed some of these issues with my brothers as I had dinner with them on a recent rainy night. My older brother explained he was interested primarily in the test’s ability to provide clues about our ancestry. (23andMe’s site includes a relative finder, and I’ve received a slew of e-mails from folks who say they may be my 4th or 5th cousin.)

He also said he was excited about purchasing science at an affordable price. Our kits, at $199, were cheap compared to the $999 23andMe charged just a little more than two years ago. And, he pointed out, because we each have a continuing subscription, 23andMe will update our tests results as the field advances.

All of this made sense to me. 

Still, if the industry’s quest is to provide definitive answers to burning medical questions, it has a long way to go. The test had more dead-ends than paths to medical self-discovery. Perhaps we should have skipped the tests and spent an extra night in Big Sur.

Related Post:
Probe of Genetic Testing Industry Finds Deceptive Marketing, Unreliable Results

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Lilly Fowler

About the author

Lilly Fowler is assistant editor at FairWarning.

3 comments to “Assuming You Want to Know, Genetic Tests Are No Crystal Ball”

  1. M. Pena

    We thought this was a solid, first-person account. So we linked to it from our “National DNA Day” story:


  2. B. Danforth

    I would find it very interesting as I have a somewhat rare genetic disease, whether they would even notice it. Running cookbook tests might well miss serious life changing issues while looking at vague, but common differences. Some like mine show up in childhood, but are often misdiagnosed, or not understood as a problem at all, others like Huntington’s don’t show up at all until the effect is especially devastating.

    I would think that not diagnosing something so life changing would open them to more charges of fraud that many missed breast cancers that so many folk complain of.

  3. Jon k

    Very insightful, thanks for the research, I always wondered about the validity of these tests

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