DNA Testing Complaints – What to Know Before You Test

If you’re considering DNA testing for genealogy or have already tested, you’ve probably heard complaints or had some yourself.

 

 

Today, I’ll focus on the biggest DNA testing complaint: Ethnicity Estimates. And I’m addressing autosomal DNA testing (atDNA), the most common test taken today, versus Y-DNA and mitochondrial DNA testing.

 

You can’t sit through a DNA class or webinar and not hear someone pretty angry about their ethnicity estimate.

These complaints come from people with well-researched genealogical records as well as those with strong oral traditions of their ancestry.

Half the audience writes off five minutes of their life because they’ve
“been there, done that” and the other half is sitting on the edge of their seat waiting to hear how the company justifies its results.

I’ve been on both sides of the aisle, so I’ll walk you through what I’ve learned.

 

DNA Testing Complaint #1

Why does my Ethnicity Estimate say I’m from “fill in the blank” ethnic region when I have NO ancestors from that area?

 

First, there’s real science behind a company’s ethnicity estimates. Your DNA testing company examines sections of your DNA where genetic mutations are known to occur. These small sections are called SNPs, single nucleotide polymorphisms (everyone calls them snips).

Genetic mutations change very slowly over time and are passed in the DNA from parent to child.

Because these genetic mutations (SNPs) tend to change slowly, they are used to determine deep ancestry, ancestry going back hundreds or thousands of years. Beyond the reach of most of our written records.

Because these genetic mutations are passed from parent to child, they can be used to find family “matches.” The more genetic mutations you have in common with someone, the closer your likely relationship.

The company takes DNA samples from “reference populations” of their choosing in different parts of the world. They find people who claim to have lived in that area for generations. People who’ve been less mobile and migratory than the rest of us. They study the reference population’s genetic mutations and come up with a DNA model for that region based on the genetic mutations these people display. Then they rely on large samples of DNA to refine the region and its boundaries. As sample sizes increase, the hope is their genetic expectations for a region will become more precise and the region (which looks like an oval from Venn Diagrams), will shrink in size.

Venn Diagram example from Wikipedia. Here’s an example using insects.

Set A is the ethnic region where creatures that have two legs live

Set B is the ethnic region where creatures that can fly live

The overlap is a region where we find creatures with two legs who can also fly-where A and B appear to have mingled.

 

If a DNA testing company guesses we have some ancestry from a certain ethnic region, it’s because we share some genetic mutations with people in that area (a recent reference population) that are distinct from people in another ethnic region.

Caveat: That’s no guarantee the reference population (people with this genetic mutation) lived there a thousand years ago (we couldn’t test the thousand-year-old population), but part of our DNA resembles the DNA of that reference population today. This is a new science, so expect things to change. But it’s a start.

Example from my life

Here are images of my Ethnicity Estimates from the two companies I currently have DNA results from:

AncestryDNA and

MyHeritageDNA

 

The dilemma: The results are pretty similar but I’ll focus on one area. Both AncestryDNA and MyHeritageDNA show I have similarities to their reference populations in the area of Scandinavia & Finland. I don’t have any genealogical records of Nordic ancestry.

The solution: For me, this doesn’t mean the DNA is inconsistent with the paper records. One is just looking further back in time than I’m able to research. I must share specific genetic mutations with people from this region. I’m willing to concede my DNA may be telling a different story than my paper records. I’m willing to live in limbo-land.

If this isn’t your situation, read on. Maybe you fit examples #2, #3, or #4.

 

DNA Testing Complaint #2

Why are my Ethnicity Estimates different at different testing companies?

 

Each DNA testing company creates their own DNA Ethnicity estimate models.

Again, my version of what they do: They select a group of people who have lived in a specific region for generations. They use these people’s DNA as base samples for this region. Then they rely on large sample sizes from each area to build their ethnic model for the region. They start forming genetic regions on a map that look like Venn Diagrams and the way companies draw and name their regions will vary because they’re each creating their own regions based on who they tested and what the science told them. That’s a good thing, by the way, and shows they’re being honest and not duplicating each other’s work.

Example from my life

Here, again, are my AncestryDNA and MyHeritageDNA estimates.

 

 

 

The dilemma: There’s variation between AncestryDNA’s and MyHeritageDNA’s ethnic regions (this is based on how they sampled and named each region). Take, for example, Ancestry’s “Scandinavia” and MyHeritage’s “Finnish” region. If we were to overlay these two regions, there is a subset that is common to both the “Scandinavia” and “Finnish” regions.

 

The solution: Both companies may see something similar in my DNA, but they’ve sampled and named their regions differently and my DNA may fall into a subset of the area Ancestry sampled and named “Scandinavia” and MyHeritage sampled and named “Finnish.” They may both be correct and are displaying my results as they fit into their particular models.

Another possible solution: Their models may be incorrect and they’ve drawn regions that are too small, areas that are not genetically distinct enough to be their own region.

Another possible solution: These regions exist but they miscalculated the probability of my mutation being a match and I have no ancestry in this region.

If you need another example, here it is, if not, skip to #3:

Example from my life

The dilemma: My genealogical records show me around 90% or more English, Irish, and Welsh. AncestryDNA shows I have 45% of my DNA from their “Europe West” region which is predominantly French & German.  MyHeritageDNA shows I have 19.6% of my DNA from a “South Europe” region or “Iberian” and this region is predominantly from France, Spain, Portugal, and Italy.

The solution:  If you look at the Venn diagram areas, both Ancestry and MyHeritage show their “Europe West” and “South Europe” regions as potentially including small parts of England or England and Wales. My genetic ancestry can be 95% English, Irish, and Welsh and these ethnicity reports will still be accurate. Again, as more people test and the sample sizes grow, these Ethnic Regions will potentially shrink in size and there will be less overlap of regions as regional DNA becomes more distinct. 

Another solution: The DNA is looking further back in time than my paper records and I have some ancestors (I’ve been unable to trace) who migrated from a more southern area of Europe to a more northern area of Europe.

Another solution: Their ethnicity estimates are off. Read on in #3.

 

DNA Testing Complaint #3

Why did my Ethnicity Estimates change?

 

Both companies clearly call these reports “Ethnicity Estimates,” not “Ethnicity Reports.”

MyHeritageDNA goes even further and says their estimates are still in beta, meaning they’re still being tested and improved upon.

 

 

Every DNA testing company will update your ethnicity estimate as their sample size increases and models change.

Early adopters, those of us who have already tested, have to expect our ethnicity estimates to change over time.

I tested back in 2000 and inwardly scoffed at the idea there would ever be a sample size large enough to accurately reflect separate ethnic regions. Eighteen years later they’ve done it. They’ve got ethnic regions and now they’re fine-tuning. Most people I know who have tested, find some resemblance between their genetic ancestry as told by their Ethnicity Estimates and their genealogical ancestry as told by their paper records.

Here’s the initial message you’ll see when looking at your AncestryDNA results, “Your DNA doesn’t change, but the science we use to analyze it does. Your results may change over time as the science improves.”

 

That goes for every DNA company you test with. In the industry, it’s just understood. The companies are trying to be honest about the results they display and we test takers need to understand and be prepared for changes and variations.

If your results come back off-the-charts crazy, wait for a DNA test sale and retest. We did. My husband tested twice, once under an anonymous name, to see if the results changed. Nope, he got the same results. (Somebody’s gotta keep these companies honest, haha.)

Example from my life

The dilemma: In my husband’s family, we knew one aunt had a different father, but after DNA testing we learned a second aunt also had a different father (DNA matches were coming back as half-sister). Then, his mother’s test results came back and said his mother was 40% Italian and all her children were showing up at least 25% Italian and we were all going crazy thinking that she also had a different father. It was high drama.

The solution: No, we didn’t get cast in an episode of ‘Scandal.’ Instead, a few months later the company’s ethnic regions updated and each family member’s estimate shifted more towards “British,” as our genealogy and oral tradition expected. That was short-lived drama.

It’s pretty exciting to see companies refine their results as sampling sizes increase. And when you have genealogical records to back up the genetic records, you gain confidence in the science and their DNA models of ethnic regions.

 

DNA Testing Complaint #4

The test must be wrong!

 

There’s also the less common, but more shocking explanation for an Ethnicity Estimate giving unexpected results. Your ancestry isn’t what you believe it to be. It’s crazy how many news reports we read where people learn their parentage isn’t what they thought it was. Children accidentally swapped in a hospital (these from the same ethnic region) who go home with the wrong parents (these were different ethnicities). Children who were fathered by the wrong sperm donor (unsure of ethnicity differences), etc.

These people are allowed to blow their stacks and vent a little steam. In the last article, the woman said she “went to her mother to express her “disappointment in the unreliability of the service” and show her the results.” The testing companies are the heroes in these cases, bringing to light mistakes and crimes that would otherwise have gone to the graves with people.

In these cases, your initial complaints will probably be based on your “matches,” not your “ethnicity.” You’re not going to give a hoot about your ethnicity results if you don’t even match the people you expect to match.

If this is tested in our generation, it can be easily caught and confirmed. If it happened a few generations back, we might assume the company got it wrong and not research the inconsistency. As shocking as it is, our paper records could be tracing the line that raised an ancestor and not the one that fathered or birthed it.

 

 

Final Thoughts from a reformed complainer

If you’ve tested or are thinking about testing, keep in mind, it’s a young science, it’s improving with each DNA sample, and you’re helping the science improve when you test and upload your DNA results to multiple sites. Check your DNA test results regularly and expect to see them change.

I’ll address some other complaints in another blog, but until then, best in your research!