The rise of companies offering personal genomic services has revolutionized the way people are thinking about ancestry. Only in the modern, DNA age could someone claim that she was of Native American heritage based on trace elements in her genome alone! Direct-to-consumer (DTC) DNA testing has become a multi-billion dollar industry in the last ten years with over a dozen companies offering to take a sample of your spit and genotype you for a fee as low as $60. The number of people who have utilized these services rose from around 4.4 million at the end of 2016 to over 12 million at the end of 2017, meaning more people had their DNA analyzed last year than in the entire history of the world combined to that point. The numbers are continuing to skyrocket. There is certainly an appeal for these services. People can learn about their heritage in general and, perhaps, something about their ancestors in particular. People can also learn about health-related traits that might impact their lives in the future. In addition, people can learn about cousins or other relatives they never knew they had.
While there are many potentially-positive uses of this technology, there have also been a lot of unintended, negative consequences. You definitely need to give serious consideration to these before you get yourself genotyped or before you buy a kit for someone you love. Health-related, genetic tests have scared people into believing they are ticking time bombs, just waiting to come down with a serious illness. This is despite the fact that most genetic health factors only tell you something about increased risks and not who will actually be afflicted with what disease. Most diseases are multi-variable and particular genetic markers are not very effective at predicting who will actually get a particular disease. In addition, a recent study found that as many as 40% of genetic variants identified in DTC tests were false positives. Thus, there are serious quality-control issues that can complicate understanding what your test results really mean.
In addition to the unnecessary angst these DTC health results can bring into a person’s life, there are the risks of unearthing family secrets long buried. A few years ago a scientist bought DTC kits for his parents as a gift. He bought a kit for himself and then opted into the “search for close relatives” feature on the company’s website. The DNA tests revealed that the scientist had a half-brother, whose genetic information was in the system. This discovery unearthed marital infidelity going back decades and led to his parents’ divorce (read more here). In several well-publicized cases, genotyping has revealed that particular sperm donors (and in one case, a fertility doctor) have fathered dozens and dozens of children. Now the half-siblings are seeking answers (see here). In another story, DNA testing revealed that two men had been switched at birth and had lived their entire lives with the “wrong” families (more here). Most people are completely unprepared for the kinds of unexpected “surprises” that can come with this kind of testing.
While these kinds of unexpected (and unwanted) discoveries may seem like an unlikely outcome for your family, there is something else you need to understand about the companies that do DTC genetic work. Ever wonder how they can afford to offer the tests so economically? It’s because what the companies really want is your DNA data. Most companies ask you to fill out detailed surveys about yourself. After they get your DNA, they are mining it for connections to the information in the surveys. With enough clients sharing their data, the hope is that some new, marketable discovery will be made. It is not an accident that 23andMe, one of the largest DTC companies, was founded by Anne Wojcicki, the wife of Google co-founder Sergey Brin. The real goal of the company is to generate data that can be mined and sold if profitable. The company may make some useful discoveries (we can hope), but most people have no idea that when they buy the kit and send in their spit, they are actually becoming part of a massive data-mining operation that will not compensate them for participating.
DTC genetic testing has been a great boon to ancestry work, but it comes with many potential pitfalls. Be sure you prayerfully consider what you are getting into when you sign up. The Lord calls you to be wise as serpents and innocent as doves (Matthew 10:16). One of the ways you do that is by having your eyes open as you interact with technological developments that often outpace our ability to evaluate them ethically.