The fact that we can now unlock centuries of family health history and heritage through DNA testing is nothing short of a miracle. Who would have thought 100 years ago, much less 50 years ago, that we would be able to map diseases, solve crimes, or identify Fido’s unique combination of breeds through one simple little test?
Really, you can DNA test your dog with the service called DNA My Dog. This novel application of the gene sequencing and profiling process was first invented in 1984 by geneticist Sir Alec Jeffreys while he was working in the Department of Genetics at the University of Leicester. But this DNA testing process is now being used for far more than clearing up family disputes about breeder integrity—it is helping society determine important issues like paternity, criminal guilt, and remedies for diseases we once considered incurable.
What do we gain from this newfound information?
DNA testing is a portal into the past. For example, Ancestry.com encourages users to click through and find their “DNA Story,” where it becomes possible to “discover the places, history, and cultures that shaped who you are today—using only your DNA.” Some might disagree, however. In a recent article in the Atlantic, Sarah Zhang commented “[DNA] is not your culture,” and it certainly isn’t guaranteed to tell you anything about the places, history, and cultures that shaped you. The scientific-seeming results you get from a home DNA kit are fun, in the manner of a party favor, but they’re not particularly reliable, especially for people from outside of the U.S. and whose ancestors are from outside of Europe.” Perhaps. But it’s still a popular way to connect with your roots—the question is, could it also be a dangerous one?
How does DNA testing work?
Every move we make on the internet, whether it’s trolling social media sites, online shopping, or researching an article, leaves a cyber DNA footprint that can be used by digital investigators to solve computer-based crimes. And in the real world of flesh and blood, that same forensic process allows detectives and law enforcement to track down criminals and crack cold cases that have been gathering dust in boxes unsolved for decades.
Here’s how it works. A sample of an individual’s DNA, typically called a “reference sample,” is collected through a buccal swab. Yes, it sounds odd but it’s really just a swab of saliva and tissues from the inside of your mouth, which of course provides unique cells for study. When this is unavailable (for example, when a court order is needed but unobtainable) other methods may be needed to collect a sample of blood, saliva, semen, vaginal lubrication, or other fluid or tissue from personal use items (for example, a toothbrush, razor) or from stored samples (for example, banked sperm or biopsy tissue). And although these samples are physical, they can still be considered a kind of bodily “data.”
Samples obtained from blood relatives can indicate an individual’s profile, as could previous profiled human remains. A reference sample is then analyzed to create the individual’s DNA profile using one of the techniques discussed below. The DNA profile is then compared against another sample to determine whether there is a genetic match.
A little more than 21% of all Americans will have been sequenced by 2025. That means enough genetic sequences have been uploaded to publicly accessible databases like GEDmatch that in 60% of cases, a given DNA sample from a person of European descent can be identified as a third cousin or closer to an existing profile. This is how police cracked the Golden State Killer case earlier this year.
By uploading a sample of the suspected killer’s DNA, police can identify a relative, and follow the family tree to catch their suspect. Even if you’ve never spit in a tube and shared your results with GEDmatch, there’s a decent chance someone you’re related to has, which means your information has been revealed by proxy.
How private is my DNA data, and who has a right to it?
Another such genetic treasure trove is GEDMetch, a website where people share their full genetic information with the public, so there are no legal hurdles for investigators trying to track someone down. By contrast, private DNA sites like Ancestry and 23andMe tend to be choosier when it comes to complying with police requests. The concern is that this data could be sold on the down-low, on the dark web, or monetized to insurance companies.
Room for Error
Tech companies (and potentially direct-to-consumer genetic-testing companies) tend to fight requests from law enforcement and force them to go through a legal process (formally getting a subpoena); on rare exceptions, they will fight to push back on those.
For approximately $99, you can roll the DNA dice to learn if you have the genetic variants associated with an increased risk of developing certain health conditions, including Late-Onset Alzheimer’s or Parkinson’s. It also provides a “Carrier Status” report, which determines if a customer carries a genetic variant for a health condition. Or, figure out why certain climates feel more at home than others by tracing your family’s origin back generations. But be forewarned, you do so at your own risk.