Direct-to-consumer (DTC) ancestry testing has become enormously popular, allowing millions to gain insights into their ethnic origins and connect with distant relatives. These at-home kits, which typically require a simple saliva sample, have created massive databases of genetic information. Submitting DNA to a private company introduces complex issues that consumers often overlook. Understanding the science, privacy risks, and social consequences is necessary before participating in this growing industry.
Scientific Limitations and Interpretation Errors
The ethnicity percentages provided by DTC tests are estimates derived from comparison against a proprietary database, not definitive statements of identity. These results are based on genotyping, which analyzes hundreds of thousands of single nucleotide polymorphisms (SNPs) across the genome. This number of markers is a small fraction of the entire human genome, meaning the test reads only select points rather than the complete genetic code.
The interpretation of these SNPs relies heavily on a “reference population,” a collection of genetic samples from people whose ancestors lived in a specific region for generations. A geographical bias exists in these reference populations, with samples from people of European descent being disproportionately represented. This disparity means results for customers with non-European ancestry may be less precise or more broadly defined, as the algorithm has fewer specific samples for comparison.
Ethnicity estimates can fluctuate and change over time, even within the same company, as algorithms are updated and more samples are acquired. This highlights the difference between a genetic interpretation and a fixed biological fact. Two different companies may provide differing percentage breakdowns for the same person’s DNA because they use different reference populations and proprietary algorithms. A low-confidence result from a DTC test may also be flagged as an abnormal result that is later proven to be a false positive when confirmed by clinical-grade testing.
Data Privacy and Ownership Issues
Submitting a DNA sample raises questions about who controls this personal data once analysis is complete. Most DTC companies are not covered by the Health Insurance Portability and Accountability Act (HIPAA), the federal law protecting medical records. They are bound only by their own privacy policies and state regulations, leaving consumers reliant on terms of service that can be vague and subject to change.
The company, not the consumer, often reserves the right to commercialize the genetic data by offering it to third-party research partners. Companies have entered financial agreements allowing pharmaceutical companies access to millions of customers’ anonymized data for drug development and clinical trial recruitment. For example, in 2018, the pharmaceutical company GlaxoSmithKline invested $300 million in one DTC company for a four-year collaboration to use genetic data from five million customers.
While data shared with third parties is generally de-identified, the ability to truly anonymize genetic data remains a concern. Customers are usually given the option to opt-in to this research, but many may not realize their consent permits the sale and transfer of their data. When a customer requests data deletion, the company’s policy determines whether the raw physical sample, such as the saliva tube, is destroyed or merely the digital file.
Unexpected Family Discoveries
A common consequence of DTC testing is the discovery of previously unknown family relationships. The search for ancestry can unintentionally reveal the existence of half-siblings, unacknowledged parents, or other close relatives. These revelations often stem from a Non-Paternity Event (NPE), where a person discovers their assumed biological father is not their genetic parent.
Receiving this life-altering information can lead to psychological and social distress for the individual and their family structure. Emotional reactions include confusion, betrayal, grief, and a reassessment of personal identity. The discovery can sometimes lead to strained or severed relationships with family members who withheld the truth.
Testing companies generally lack the infrastructure to provide adequate psychological support for customers who receive unexpected or distressing results. While customers may be advised to consult a genetic counselor, many process the information alone or with limited resources. The burden of managing the emotional fallout is often left entirely to the individual, as the company acts merely as a data provider.
Use of DNA Data in Legal Investigations
The large databases of genetic profiles created by DTC companies have become a powerful, yet controversial, tool for law enforcement. This practice, known as investigative genetic genealogy, involves uploading crime scene DNA evidence to a public database, such as GEDmatch, to search for distant relatives of the suspect. By identifying third or fourth cousins, a genealogist can build a family tree to narrow the search down to a single individual.
Even if a person has never taken a DNA test, their genetic information can be used to identify them through a close relative who has submitted their DNA. A significant portion of the population can be identified through this familial searching technique. Law enforcement can compel private DTC companies to release customer data, typically requiring a warrant or subpoena to access data from the largest commercial providers.
The lack of clear federal regulation means that individual company policies determine the level of protection afforded to a user’s genetic privacy. This access creates an ethical debate, as the consent given by one person can inadvertently compromise the genetic privacy of all their relatives. Participation in a recreational ancestry test carries implications far beyond the individual user.