Catharine Wang: DNA testing carries hidden downside

Aggressive marketing techniques and the popularity of bestowing recreational ancestry tests as gifts have led more consumers than ever to the world of personal genetic testing.

The recent arrest of a Golden State Killer suspect heightened concerns about privacy and ethics, after the way law enforcement used a third-party DNA analysis company to identify close relatives and hone in on a likely offender.

The company GEDmatch is well-known among genetic genealogy enthusiasts. When consumers want to learn more about their relatives than previously revealed by commercial testing, companies such as AncestryDNA or 23andMe can seek third-party companies like this one for further interpretation of their DNA results.

Genetic genealogy companies primarily use ancestry information. But the raw DNA data they provide actually contains much more.

Guest Writer

Catharine Wang is an associated professor in the Community Health Sciences Department at Boston University. She obtained her doctorate in Health Behavior and Health Education from the University of Michigan. An expert in survey research, intervention development and program evaluation, she is currently serving on a genetics advisory panel with the National Cancer Institute. She has served as printipal investigator on several grant projects examining comprehension and use of complex health risk information.

In addition to clues about where your ancestors came from, DNA holds information about your own medical risks. Here, at the intersection of recreational genetic genealogy and personal health information, is where direct-to-consumer companies are generating some unintended supplementary effects that can have personal consequences consumers may not be prepared for.

I approach this area from the medical side. My own work focuses on how people use genomic information for personal health benefits. In particular, I’ve examined when and how people decide to undergo genetic testing, and how they understand and cope with their results.

The rise of direct-to-consumer genetic testing has led to a sometimes dodgy do-it-yourself world of genetics. It may provide access to personal genetic information for the masses, but in many cases, individuals aren’t fully aware of all they may find out, or how their data may be used.

My interest in the unintended consequences started a few years back with a patient who sought help in interpreting data she received from a third-party company suggesting she was at increased genetic risk for breast cancer.

Concern over what had been identified in the interpretation report ultimately led this patient to consult a genetic counselor — a trained professional who can advise on the genetic risks for various diseases. The counselor eventually determined the result was nothing that warranted concern.

This “false positive” case raised red flags for me.

I interviewed this patient to learn more about why she’d used this company, which I had never heard about. It turned out she’d stumbled into the area of genetic testing for health risks due to an interest in genealogy. While watching Henry Louis Gates’ PBS show “Finding Your Roots,” she saw an ad for one of the commercial direct-to-consumer companies offering ancestry testing.

Once the patient learned her ancestry results, she realized an entire world had opened up in terms of other possible nuggets of information she could discover from her “raw” DNA data. So she purchased access to a third-party health app to interpret her raw DNA.

These results — provided without consultation with a medical professional — which led her to a clinic.

Currently, there are many of these third-party apps or online services available to consumers. They’re not regulated by the Food and Drug Administration since, as argued by the companies behind them, they just serve as a “bridge to the literature.” They provide access only to the scientific evidence base.

My colleagues and I surveyed customers of these third-party companies to learn more about their motives for exploring the raw DNA data they’d received from commercial testing companies. Approximately two-thirds of consumers we surveyed were highly motivated to explore raw DNA for ancestral details. Forty percent were interested in both ancestry and health information.

Sixty-two percent of our respondents used GEDmatch, highlighting the extent to which DNA data heavily protected by companies such as AncestryDNA and 23andMe are unguarded by consumers themselves. Many choose to freely upload that data in hopes of finding other relatives. Notably, almost three-quarters of consumers reported using more than one third-party company to interpret their DNA.

Some might argue these tools provide a beneficial service for consumers, particularly when in regard to learning more about their health risks. In cases where genetic risks are determined via clinically validated tests, it can be empowering. Angelina Jolie represents the perfect example.

Yet, the validity of genetic tests consumers have direct access to remains questionable. In fact, a recent article by scientists at one of the clinical testing labs medical providers rely on indicated about 40 percent of results reported from raw DNA interpretation were incorrect. Thus, four out of 10 people are told they have a greater risk for a disease when they do not. That’s an exceedingly high number of individuals to stress out with a false positive.

My ongoing work has found “worry” is the primary driver for patients to seek out medical assistance in raw DNA interpretation. As such, this false positive rate has a notable downstream burden on the healthcare system.

Social media sites like Reddit are filled with examples of consumers confused by reports generated from third-party companies, which vary greatly in clarity and quality. Some have learned from a report they might have a BRCA variant conferring high risk for breast and ovarian cancer.

It doesn’t have to be this way. There are genetic counselors who specialize in interpreting these kinds of results and helping patients determine what to do.

Genetic counselors, meanwhile, are frustrated.

The message from commercial testing companies has led to unrealistic expectations from consumers about what they can learn about themselves. It’s challenging for counselors to correct misconceptions, especially when they are met with resistance from patients.

In 2017, direct-to-consumer testing exploded. And once the genie is out of the bottle, it isn’t going back.

The Golden State Killer arrest is only highlighting the ramifications of genetic genealogy and widespread use of third-party DNA sites. The findings, it seems, are broader and more ambiguous than consumers evercould have anticipated.



If genetic testing finally tracked down the heinous Golden State Killer, I'm all for it.

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