Discoveries and dilemmas

The stories, surprises and pitfalls of consumer DNA products
A person in a hoodie sitting at a desk looking at a laptop. A vial to the right labeled DNA test. A DNA home test kit on the left.
Illustration by Carl Wiens,

In 2017 Theresa Tayler spit into a tube, sealed it in a box and shipped the package off for analysis.

It was her mom’s idea to have the family’s DNA examined by 23andMe, one of the world’s largest direct-to-consumer genetic testing companies. Her parents had already sent their saliva off for analysis. So had some aunts and cousins. Even Tayler’s 90-year-old grandfather gave it a try.

Once their DNA was posted on the portal, everyone could log into the company’s website and watch their family tree grow as more relatives sent in samples.

Months later, her parents pointed out something they’d noticed. Her grandfather hadn’t popped up in Tayler’s father’s family tree. He was also missing from hers. “I was like, ‘What?’ ” says Tayler, who graduated from MRU’s journalism program in 2005. She was stunned. She knew the tests weren’t 100 per cent accurate, but these results were either flat-out wrong or everything she knew about the paternal line of her family was incorrect. Based on the company’s analysis, her grandfather did not appear to be a blood relative of Tayler or her father.

Her grandparents had spent their whole adult lives together until her grandmother died in 2017. They’d married in their late teens in London, England, and emigrated from Britain in the 1950s with their six-year-old child, Tayler’s father, in tow.

Tayler knew the English side of her family well. After high school, she’d spent a gap year in London, hanging out with cousins and aunts. She had been close to her grandmother, a staunch atheist who read poetry and oozed kindness. Her grandfather was more aloof, mostly because he was working, golfing or skiing when Tayler was growing up. When she became an adult, that relationship changed. Recently, he’d been diagnosed with advanced stage cancer. Tayler visited him on trips to Vancouver, BC, where he now lived.

The results of the DNA analysis put into question who she and her family were. Tayler knew these sorts of tests sometimes unexpectedly unveiled secrets — she’d half expected that from her mother’s side of the family. But not this. She didn’t know if the secret had ever been known to anybody besides her grandmother.

“People think that the hard part of the trauma is finding that out,” Tayler says. The hardest part is what comes next. “It’s only because of this [expletive] DNA test.”

Direct-to-consumer (DTC) genetic testing will turn 20 years old next year and has been an enormous hit with consumers. By 2019, more than 26 million people had submitted their DNA for genetic testing by the four leading commercial companies, 23andMe, Ancestry, GeneByGene and MyHeritage, according to MIT Technology Review. In early 2024, 23andMe reported having more than 12 million customers, while Ancestry’s database contains information from 25 million people. These two leaders in the DTC genetic testing industry have now amassed the world’s largest non-governmental collections of human DNA information.

DTC genetic testing differs from the genetic testing performed by health systems. The latter usually answers questions about a person’s genetic risk for disease. It’s protected by legislation, setting out privacy guardrails for health information and is often delivered by a genetic counsellor.

DTC testing follows different rules. It doesn’t require a referral from a physician, and is advertised as technology to fulfill curiosities about a person’s ancestral lineage and potential health risks. Some companies even offer guidance about a person’s innate athletic abilities or ideal diet based on the DNA analysis.

The large databases owned by these companies also hold enormous promise in the treatment and understanding of disease and genetic risk. They contain huge troves of data about human beings that could help researchers identify new ways to prevent or treat disease.

But sometimes, the information stored in these databases leads to uncomfortable consequences — both for the people who’ve submitted their data and for their families. It can be more than they bargained for when they sent their saliva off in a tube.

Forcing old secrets into the open

Tayler, who spent a decade working as a journalist and in communications roles before starting her own company, was angry at the results. She wanted more answers and had no one to guide her through the next steps. She began questioning her extended family to help put together the human story to go along with her genetic results. “Did you know that Granddad isn’t my Dad’s birth dad?” she asked her cousins and aunts. To her shock, some responded they did, but they’d never wanted to say a word to her or her father. Her father’s younger brother said that he’d known for years; cousins told her that they thought she already knew. The story of her father’s parentage had somehow become the secret that many carried, but no one acknowledged.

Looking back, Tayler says she and her father ignored clues. She remembered sitting in a pub while showing her elderly aunt the photo of her and her cousins; her aunt had laughed when Tayler said they looked alike. “She was like, ‘You think so, eh?’ ” Tayler recalls.

Her grandparents had both been born in the east end of London in the 1920s, and they were in their teens when the Second World War broke out. Their neighbourhoods endured some of the worst of the Blitz. Her grandparents met after the war, started dating and married in 1949, in what Tayler always imagined was the euphoria of those postwar years.

Now, Tayler understood that her grandmother must have been going through agony when she realized that she was carrying a child out of wedlock. She didn’t know if her grandmother even knew with certainty who the father was. Tayler doesn’t feel anger toward her grandmother about that. “Can you imagine coming out of a war like that?” she asks. “It must have been like this: ‘We’re alive! We didn’t die in the Blitz.’ How can we judge that?”

She didn’t want to risk upsetting her grandfather, who was dying of cancer, but she also did not want to miss out on her last chance to ask him what he knew. She flew to Vancouver, posing the question that felt most appropriate: “How many kids do you have?”

A scientist, a woman and a man sitting on a couch, looking very disapointed.
Illustration by Carl Wiens,

She had to repeat the question when he didn’t answer at first.

“Two and half,” he eventually replied.

She feels protective of her grandparents who kept this hidden for 70 years. But she sometimes feels frustration towards her family who didn’t say anything.

After poking around in her grandmother’s history, looking for clues, Tayler has not uncovered an answer about who her blood grandfather is. She isn’t certain if she wants to reveal a secret that her grandmother had hidden until 21st century technology forced it into the open.

Tayler has learned that her grandmother had an American boyfriend when U.S. troops were stationed in London. She also had a relationship with a German prisoner of war, to whom she’d been writing after the war. Having read these letters, Tayler learned that her grandmother suddenly stopped corresponding with him, ignoring the man’s queries about what happened to her. Tayler has also considered that something terrible happened to her grandmother that resulted in an unwanted pregnancy. For now, these are just theories, sparked by the result of a genetic test that she did for fun. 23andMe didn’t reveal any unexpected blood relations. Tayler suspects she might find some relatives on her biological grandfather’s side if she submits her DNA to other genetic testing sites. But she’s had enough genetic testing surprises for now. “I’m glad we did it. It shed a lot of light on stuff that I didn’t even realize it was going to shed light on,” she says. She’s become comfortable with this new story: her
grandfather, who wasn’t her father’s father by blood, stepped into the role of father and never wavered. The rest, for now, is her grandmother’s story to keep. “That story lives with my grandmother. And I used to be angry about it. But I’m starting to realize, as much as it pisses me off that other people knew, it’s her story,” she says.

Scientific analysis or 'costly entertainment'?

Forty-four years ago, when an international consortium of scientists set out to sequence the human genome, they were not thinking that their work might send shockwaves through families. The Human Genome Project, which kicked off in 1990 with a budget of $200 million a year, was ambitious. Its great promise was a future with important discoveries about the causes of disease and a map to treat or even prevent disease.

Thirteen years later, the International Human Genome Sequencing Consortium announced that it had generated a complete human genome. Two years after that, a new industry got its start: DTC genetic testing. Thanks to the work of the consortium, companies could now quickly and, relatively cheaply, scan the labyrinth of human DNA. This meant that people could spit in a tube and send their saliva or cheek swabs for testing, with the price tag of around US$1,000 in the early years. As the technology improved, the cost fell dramatically, to about $99 per test by 2012, and the market for genetic testing exploded. By 2019, there were over 250 companies offering DTC genetic tests.

But there are significant limitations to the results given by many of these companies, says Dr. Samanti Kulatilake, PhD, an associate professor of anthropology at Mount Royal.

Kulatilake is a biological anthropologist who specializes in the study of ancient human remains such as bones and teeth, in order to understand past lifeways, migrations and ancestry. In 2017, she spent a summer studying at Lakehead University’s Paleo-DNA Laboratory in Thunder Bay, ON. There, she learned DNA extraction, amplification, sequencing and interpretation by practicing on herself. She used forensic techniques on her blood, cheek swabs and hair follicles to analyze her mitochondrial and nuclear DNA, looking for markers that are associated with people from different parts of the globe.

There is a difference between finding a marker for ancestral roots and the results provided by genetic testing companies, she says. DTC companies offer their consumers a detailed breakdown of their various ancestral ethnicities, the results of which include such information as “36 per cent Eastern European, 11 percent Italian” and so on — the kind of outcomes that often surprise people. They say things like: “I didn’t know I was Italian!” or “I always thought my roots were entirely German!”

But the science behind these reports is not exact, says Kulatilake. “This idea of assigning somebody with a percentage is very flawed.”

While the science for genome analysis is robust, there are major limitations in the way that companies interpret the results for consumers, she says.

“The start is scientific, but the outcome may not be so because of the way the data is presented to the consumer.”

For one, companies often break down ancestry into percentages based on biomarkers associated with people known to live in different geographic regions. But it is hard to narrow down those markers to an area as small as, say Italy. Particularly when a person’s ancestors were in that region generations ago. What’s more, companies’ interpretations are based on the information in their database, which often includes large samples of Europeans but under-represents people in the Global South. Finally, these tests cannot account for human migration over millennia, points out Kulatilake. People have been moving and interconnecting around the globe from long before the current borders of nation states were set out, she says.

“How can you do this assessment based on a species that is so mobile? We are one of the most mobile species ever,” she says.

The flaws in this system are regularly reflected in test results. In 2019, CBC’s Marketplace reported on identical twins who purchased home kits from five companies and mailed samples to each for analysis. The twins did not receive matching results from a single company. Other families have reported that ancestral roots may appear in one generation but disappear in the next.

Kulatilake tells people not to take the results too seriously. “It is entertainment, but there’s a slippery slope there that one must be very cautious about,” she says. “It’s also costly entertainment — costly for the people who are submitting and also costly for humanity.” There can be racist connotations when people seek to define themselves by modern-day nationalities, she says.

There’s one important fact always overlooked in genetic test information, she adds. Humans are 99.9 percent genetically similar. Our differences are in the 0.1 per cent. “This dissimilarity is very very tiny compared to the sum total of the shared genetic basis of human existence,” she says.

Genetic data hacks

Privacy experts like Dr. Khosro Salmani, PhD, an assistant professor in MRU’s Department of Mathematics and Computing, have long warned that consumers who share personal information with genetic companies risk
having sensitive information stolen.

In 2017, The Economist reported that data has replaced oil as the most valuable resource in the world. Personal data, especially, has enormous value. Many actors — from individual hackers to multinational corporations — want those details, whether it’s birth dates, names of family members or hints about items that someone is more likely to be interested in purchasing. Organizations use this information to identify markets for their products, while hackers make money illegally by selling, threatening to sell or hijacking personal data.

The kind of data collected by DTC genetic testing companies is particularly sensitive, says Salmani. “What we have to consider is that it’s not only going to impact me, but our family, and all of the generations right after that.”

Genetic testing companies have been hacked in the past. In 2020, hackers got into GEDmatch, a large genealogy site where users upload their DNA information to search for relatives. Days later, GEDmatch customers who’d also shared their data with MyHeritage, another genealogy site, were targeted again in a phishing attack.

A person examining a wall covered in portraits.
Illustration by Carl Wiens,

That was only the beginning. In 2023, the industry was hit by the largest data hack in its history. Hackers accessed the personal information of about 6.9 million profiles at 23AndMe—almost half its customers—between April and September 2023, and posted a sample of the data online. The hack appears to have targeted customers with Chinese or Ashkenazi Jewish heritage, and their personal genetic information was then compiled into curated lists that were sold and shared on the dark web.

Since the breach, 23AndMe customers have launched class-action lawsuits in British Columbia and the United States. At this point, it is too early to know what the consequences may be for the people who were hacked, Salmani says. The data could be used to influence people’s premiums for health or life insurance.

Submitting your data for testing “is a big decision,” he warns. He urges people to do their homework before sending their DNA for any analysis with a DTC genetic testing company. They should always look carefully at a website before making an online account to confirm that it is legitimate, and review a company’s privacy policies, which every Canadian company is required to do by law. These policies outline how data is going to be used, what kind of security actions are being taken to ensure that users’ data are protected and the services these companies provide. Many have opt-in clauses regarding use of their data for research or by law enforcement. Users should only sign up for companies that verify new users through a multi-factor authentication system, Salmani says.

The push from outsiders to get at your personal data is only going to increase, he adds. “Every day, we are becoming more and more susceptible to these types of attacks, and we should definitely do more in order to protect those kinds of things,” he says. “And when it goes to the genetic data, it becomes even more sensitive.”

DNA detectives

Data from genetic testing companies is also being enlisted to solve crime — sometimes through controversial methods.

Police in Canada first used DNA in 1987 when they were looking for a man who’d sexually assaulted seven women in Edmonton. Within the decade, the Canadian government gave the go-head to police to take DNA samples from anyone convicted of a serious crime. That bill laid the foundation for the RCMP’s National DNA Data Bank, which contains two main collections of DNA today.

The first, the Convicted Offender Index, holds DNA from more than 450,000 people convicted of a serious crime in Canada. The second is the Crime Scene Index, a repository of more than 220,250 DNA samples recovered at crime scenes. A computer network called CODIS, for Combined DNA Index System, created and maintained by the FBI in the U.S. and shared with more than 90 law enforcement laboratories in over 50 countries, including Canada, links this information with police across the country.

DNA testing has improved since the database was first launched. Police can now retest old samples using modern methods and come up with DNA profiles for suspects in cases that have long gone cold. This has happened while genealogy databases owned by private companies were rapidly growing. Inside, these databases hold a treasure trove of information; they show family trees of people who’ve submitted their DNA for testing.

For investigators, these trees serve almost like road maps marking out the path from a DNA profile to the identity of a suspect. It’s given rise to a new specialty in law enforcement: investigative genetic genealogy. Its practitioners cross-refernce the DNA samples collected at crime scenes with genealogy databases to identify criminals.

Most famously, genetic genealogy solved the mystery of the Golden State Killer — a man who’d murdered at least 13 people and raped nearly 50 in California in the 1970s and 80s, and was arrested in 2018 based on DNA samples taken from a crime scene 38 years prior. The case kicked off a new era in DNA-based investigations, and since then, genetic genealogy has led to many cold-case arrests in the United States.

Genetic genealogy is used less often in Canada. Canadians do not submit their data as frequently to genealogy websites, rendering the databases less effective here. Still, genetic genealogy has produced high-profile results in Canada. In 2020, Toronto police announced they’d identified the killer of nine-year-old Christine Jessop, who was abducted, raped and killed in 1984. Guy Paul Morin, the family’s neighbour, was wrongly convicted of her murder in 1992, and was cleared in 1995 after DNA typing definitively excluded him.

An illustration of a magnifying glass and a DNA strand.
Illustration by Carl Wiens,

In Calgary, genetic genealogy recently helped bring charges to a longstanding cold case. For nearly half a century, police did not have a suspect in the 1976 murder of 16-year-old Pauline Brazeau, a single mother whose body was found on a rural road outside Cochrane.

In 2021, the RCMP submitted forensic evidence from the crime scene to Othram, a Texas-based company that does advanced DNA sequencing for law enforcement. Othram gave the RCMP a comprehensive DNA profile for the suspect. From there, the RCMP turned to specialists at Convergence Investigative Genetic Genealogy, an American company that compares DNA profiles against databases where users send their DNA profiles. That led to a suspect. In November 2023, the Calgary Police announced that they’d arrested 73-year-old Ronald James Edwards of Sundre on charges of Brazeau’s murder. His trial is scheduled for March 2025.

DNA technology is changing so rapidly that the laws in Canada have fallen out of date, says Doug King, a professor of criminal justice at MRU. Here, police are not permitted to use familial DNA to identify a suspect using the national DNA databank. If evidence is collected from a crime scene, it cannot be tied to a relative who is in the Convicted Offender Index and then used to pinpoint their relation. (By comparison, most U.S. states allow this.)

But police have turned to non-government genetic databases to identify suspects. Some, but not all, databases ask users to give their consent for law enforcement. In the 2020 hack of GEDmatch, hackers changed the settings of people who’d submitted their DNA and opened everyone up to law enforcement analysis.

King says that a key principle in Canada is that people are owed a reasonable expectation of privacy against the government. He is concerned that people may have their DNA examined in a police search without their permission.

“There’s an old adage related to search and seizure: an unreasonable search cannot be justified by what you find,” he says. “And that’s not just a quaint saying. It is the foundation of section eight of the Charter. We’re toying with some really core principles related to the Canadian Charter of Rights and Freedoms.”

A Senate committee is currently considering a bill that would change Canadian laws around collection of DNA evidence, aligning them more closely with the United States. If passed, Bill S-231 will mean that anyone convicted of a crime punishable by five years or more of jail time, not just those convicted of a serious crime, will have their DNA collected — a change that would expand the National DNA Data Bank and would have helped identify the killer of Christine Jessop years ago when her murderer was convicted of drunk driving. The bill would also allow police to use DNA samples to identify potential family members of suspects.

King hopes Canada does not follow the U.S. example, saying the Charter is designed to protect from government overreach. As it stands now though, “technologies are outstripping the law,” he says.

Personal discovery – and possibly much more

Genetic testing companies sell customers on an idea that they will learn about themselves at a deeper level. “Know your personal story, in a whole new way,” promises 23AndMe. “Get to know you” is AncestryDNA’s slogan. But the reality is that
these tests are not just about personal discovery. Hackers may also get to know you. Your personal details might be widely shared. Family secrets can get pushed out into the open.

Yes, these tests tell a story about one person’s DNA, but there’s no telling how those stories end.