How Accurate Is an Ancestry DNA Match?

Ancestry tests exploded in popularity in recent years, with the processing of at-home DNA kits reaching an estimated 30 million by the end of 2019. But how accurate are ancestry DNA matches? As you might expect when DNA is involved, the answer is complicated.

How accurate are ancestry DNA matches?

DNA kits are especially popular gifts around the holidays, providing a fun experience for consumers who want to learn about their family’s past.

With the tests provided by most companies, users spit into a tube and send the sample to the company’s lab. There, lab technicians use DNA-reading technology that tosses unrelated elements that show up in your spit—think proteins—and sifts through genetic data, a process called “genotyping.” Something like 99.9% of our DNA is the same, so the technology hunts for genetic differences in the genome, the differences that make you who you are and match you with relatives and regions.

“They look at 700,000 markers across your genome,” said CeCe Moore, the chief genetic genealogist for Parabon Nanolabs. “They’re not sequencing it and looking at all three billion As, Cs, Ts and Gs. They’re just looking at markers that tend to change quickly, that have the tendency to mutate and tell us a lot about our differences. Those are the things that tell us who our close relatives are and where our ancestors were.”

There is a difference between the relative-matching aspect of DNA testing and the regional-placement part of it.

Relative matching: The closer the relative, the more accurate

The matching in DNA testing, when companies use your genetic makeup to determine your relatives and family history, can be “very accurate,” Moore said. That’s why she doesn’t recommend taking an ancestry DNA test unless you’re fully prepared for unexpected results. Thousands of tests, Moore said, have led to the discovery of previously unknown siblings, parents, cousins and more.

Related: How a Genealogist, DNA and BeenVerified Helped Solve a Family Mystery

“This is really important for people to understand: There has been a lot of talk about these tests being unreliable and people rejecting newly found relatives,” Moore said. “But they are never wrong about close relatives—a new sibling, a child, a parent. It is legitimate. You can absolutely count on those predictions.

“As they get more distant, it’s harder to determine how closely related they are to you,” she said.

DNA tests have also been immensely helpful in breaking through genealogical brick walls that previously prevented people from finding relatives. Moore specifically pointed to people with African-American ancestry, who often can’t find familial relations past the Emancipation Proclamation and the 1870 census, or those with Jewish heritage whose families were decimated in the Holocaust. The rise of adoptions and donor-conceived children adds to the potential mysteries of genetic origin.

DNA testing “can really help you extend and expand your family tree,” Moore said. “We’ve seen amazing stories over the years.”

Regional origins: Evolving data adds questions

The regional-placement attempts in DNA tests tend to be murkier.

DNA testing, because the researchers know which data to evaluate, can typically differentiate between someone’s continental ancestry—African, Asian, European, Native American and so forth. But, Moore said, naming specific countries, with percentages, on test results can be misleading.

The leading DNA testing companies started out using genetic information from publicly shared research. In more recent years, they added the DNA data from their own customers to the pool they use to compare with new test-takers. This is why your results can change over time as companies add clients.

“They’re getting better, but that is where you can’t base your understanding of your family tree on those percentages,” Moore said. “The tests don’t always read Italian DNA well, particularly if you have Northern Italian ancestry, for example. You can’t put as much stock on those very specific ancestral predictions, where you’re getting down to countries that are very close together.

“People move back and forth. There’s migration. Borders change,” she said. “So, don’t get upset when you don’t get the exact ethnicity predictions they expect.”

Ancestry DNA tests: Some providers and costs

Three companies command the largest number of processed DNA tests among them: AncestryDNA, 23andMe and Family Tree DNA. A fourth company, My Heritage, has grown in more recent years. Here are the costs for these services as well as some pros and cons for each. And as a note before considering any of the services: Do your research on what each company does with your personal information.

23andMe

Thise company boasts more than 12 million processed DNA tests and, in an evaluation of ancestry DNA services in 2019, The New York Times said 23andMe “has the most polished site design.” But the site doesn’t let customers upload their DNA test results from competitors, something the other leading ancestry DNA services allow for cross-referencing.

• The Ancestry + Traits Service provided by 23andMe costs $99 and provides DNA testers with an ancestry breakdown.
• The Health + Ancestry Service is $199, showing results that 23andMe claims “can help make it easier to take action on your health.”
• Customers can combine the two tests with a 23andMe+ membership that costs $198.

AncestoryDNA

Lauded by The New York Times as “the best DNA testing kit” service, AncestryDNA customers get access to the largest pool of DNA test results among the industry’s leaders and also can expect reliable family-matching. The Times does note that AncestryDNA can’t independently track your maternal or paternal heritage—and has a blind spot when it comes to migration paths out of Africa.

• AncestryDNA offers three different rates, from $99 to $119.

Family Tree DNA

The Family Ancestry test will give customers the big picture look at their regional heritage, while the maternal and paternal tests more closely track family lineage. The New York Times commends Family Tree DNA for tracking familial migration patterns but notes that tracking both sides of the family can get expensive. While Family Tree DNA, like AncestryDNA, allows you to upload your DNA test results from other sites—yes, you still have to pay for each company’s services—the site does voluntarily provide information to law enforcement.

• The company’s Family Ancestry test is $79, while the Paternal Ancestry test runs $119 and the Maternal Ancestry test goes for $159.

MyHeritage

A company that started in 2016, MyHeritage works with less data but has grown in respectability and often gets lumped in with the three industry leaders.

• MyHeritage offers everything from a free trial that helps you build a 250-person family tree to a $299 Complete Package deal that allows users to access unlimited family tree details and historical records.