Genetic Networks, Part 6: Find Same Matches Across Multiple DNA Websites

In genetic genealogy, the more matches we have, the greater our ability to make ancestral discoveries. Having more data points increases our confidence with the sub-clusters observed within genetic networks as discussed in the previous post in this series (Part 5). It can also help us prioritize our research efforts as we progress into documentary research (Part 7 of this series, which is forthcoming October 21).

In this post, I share tips and techniques for finding the same matches from one DNA testing website in your list of matches at other testing websites. Because Ancestry has the largest database of autosomal DNA testers and, in my opinion, the better search filter, my search strategy predominantly discusses how to find Ancestry matches within MyHeritage, FamilyTreeDNA, and Gedmatch. However, the search strategy works between any database.

Why Search Other DNA Websites for the Same Matches

It’s beneficial to find matches in other testing websites because not all of us who test our DNA have tested using the same company. When you concentrate all your efforts in one DNA testing database, you may miss out on the one match confirming a previously held hypothesis or opening up new a research direction. Also, not all of us upload our family tree to every testing website, so finding the same match at another website may help you find that match’s tree.

Another point to consider. Ancestry does not permit people to upload DNA test results from other testing companies into their database, but most other companies permit tests to be uploaded into their respective databases. So, you’re more likely to find Ancestry tests on other websites than the reverse. If a user has tested at Ancestry first, their subsequent upload to another website may also have their most recent version of their family tree.

As mentioned in Part 4 of this series, the other DNA testing websites (e.g., FamilyTreeDNA, MyHeritage, and 23andMe) and DNA comparison websites (i.e., Gedmatch) provide chromosome browsing tools. These tools enable segment triangulation, which genetic genealogist Blaine Bettinger indicates is one of the two hurdles genealogists must overcome when using DNA matches as evidence in proof arguments.

It’s not reasonable to expect that all matches at Ancestry, for example, should be found on other testing websites. However, the reality is that you don’t need to find all of them — you just need to find one. Once you find it, you can find some of the other members of the same genetic network here by using that testing website’s shared match filter, which was discussed in Part 3 of this series. You may see some of the same matches here, but the hope is that you discover new ones, too.

How to Find Genetic Networks at Other Testing Companies

The assumption is that your DNA has been tested or uploaded to more than one DNA testing website. Locating matches from one testing website among your list of matches at another testing website is a bit cumbersome, but it’s worth the time investment as it can help you find other matches that open up a new research strategy. I offer several search strategies to reduce the effort in locating relevant matches in other testing websites.

Find Active Accounts

At least within Ancestry, clicking on the match name takes you to the match’s member page where it displays, among other items, when the manager of the kit was last active (see image below). Those who are active are more likely to have uploaded their DNA results to multiple testing companies. Match names have been anonymized using the letters A (DNA tester), B (viewed match), and C (shared match) as described in Part 1 of the blog series.

If the member was active within the last few months, I send them an Ancestry message asking them if they posted their DNA to other testing websites as there is a greater likelihood that active users will reply. While I can search for this match without their response, it may help to know their match name at the other testing websites in case it is different than what they used at Ancestry.

Concentrate on Larger Matches

Matches sharing more DNA with us – as measured by centimorgans (cM) – will typically be associated with a larger genetic network because there is greater opportunity for other matches to share a portion of the same segment(s). So unless you don’t have any other options, focus on larger cM matches.

Prioritize Matches with Less Common Names

At FamilyTreeDNA, MyHeritage, and 23andMe, the search function presents results from both the match name and surnames in the match’s family tree. So, you can image searching for a match whose surname is “Smith” will return more results than say “Eckleberry”, which is less common surname. Therefore, prioritize matches with less common names keeping in mind that you only need to find one of the matches in your current genetic network to discover the same genetic network on the other testing website.

Try Multiple Variations for the Same Name

You can always search using the match’s full name but realize they may not have entered it the same in each website. For example, I can enter my own name as Richard Wilson, Rick T. Wilson, R.W., etc.

Set a Lower Priority for Matches Using Pseudonyms

While testing websites encourage testers to use their actual names for their DNA kit, testers can enter anything. Also, there’s no guarantee that testers use the same pseudonyms, but sometimes you can get lucky.

Search for a Unique Surname in Your Match’s Tree

If all else fails, try to find a match by searching for one of his or her ancestors who have a unique surname even if it’s not the one you’re interested in. This of course assumes they uploaded a family tree. For example, I was looking for a match named “John Smith”. According to his family tree, one of his great grandparents was named “Vandergrift”. I couldn’t reliably find him under his Smith name, but searching for Vandergrift produced fewer results — one of which was for him under the match name of “J Smith”.

Genetic Network Search Result Examples

As noted earlier, my predominant DNA testing website used for genetic networks is Ancestry. So, the examples for finding genetic network members from Ancestry will be within FamilyTreeDNA, MyHertitage, and Gedmatch. Other testing and analysis websites exist, but these are the ones I prioritize.

MyHeritage

Of the previously mentioned testing and analysis websites, MyHeritage is the one go to first after Ancestry. I like its search filter and how it presents the genetic network. As visualized in the image below, some shared matches (C) are highlighted using a special icon indicating that the a triangulated segment has been found between the tester (A), the viewed match (B), and a shared match (C). This is a good indication that the inherited segment was received from the same common ancestor. If you scroll down to the bottom of the match page, the chromosome browser highlights which chromosome(s) contain the triangulated segment(s) between “A” and “B”. I found one of my Hill genetic network matches from the last post (Part 5) here in MyHeritage, and the triangulated segment is show below.

Clicking on a segment in the chromosome browser provides the start and stop position (genomic position) used to identify other matches who share the same segment within and across other testing sites, which is discussed later in this post. Keep scrolling down your list of shared matches between “A” and “B” to discover more “C” matches with triangulated segments. Note: the other matches without the triangulated segment icon do not necessarily mean they are misclassified member matches (see Part 2), although they could be. These “C” matches without an icon could still share the same common ancestor but may have inherited a different segment than inherited by “A” and “B”.

FamilyTreeDNA

There are two approaches to find members of your genetic network on FamilyTreeDNA. Members can be found by searching within your list of matches using the previously discussed search strategies or directly through the Chromosome Browser.

FamilyTreeDNA recently replaced its family tree feature with MyHeritage’s family tree tools, which improved its search function. This made using my search strategy tips easier to use. When you find a relevant match, click on the box next to the match’s name and a new window appears at the bottom of the page to compare the match in the chromosome browser. Click the “Compare” button and the chromosome browser page appears. Click on a segment to reveal the start and stop positions.

If you already know the start and stop positions for matches within a genetic network, an alternative approach for FamilyTreeDNA is to directly use its Chromosome Browser Tool within the Autosomal DNA Results & Tools section on the main landing page (see image below). Once at the top of the chromosome browser page, use the DNA Matches filter to select the matches for whom you wish to view their segment details. If you know the side of the tree on which the match is associated ( i.e., maternal vs. paternal), select as appropriate. If you do not know or cannot make a determination, download all match segment information but know that some of the matches may be irrelevant (i.e., maternal vs. paternal) even though they are at the same position on the segment. Next, click the “Download All Segments” button and locate the downloaded .csv file, which can be viewed within any spreadsheet program.

I’ve anonymized a portion of the DNA segment file below, added commas to the start/stop positions to help read the numeric data, and sorted the data by chromosome and start position to more quickly locate other matches sharing the identified segment(s). I then use the match name to go back into my match list to review the match’s family tree, evaluate the shared matches between myself and the match, and contact the match as necessary.

Gedmatch

Once you find the same genetic network at any of the above DNA testing websites, you can take note of the segment information and use Gedmatch’s Segment Search tool to find all your people who match you at or near the same start and end position on the relevant chromosome(s). Be advised of two items. First, the Segment Search tool is a Tier 1 Tool and requires a subscription, which can be per month if you do not intend to use it regularly. Second, the resulting segment data represents both your maternal and paternal sides of your tree so some matches may appear to share the same segment data, but it may be on the wrong side of your tree. To use the Segment Search tool, follow the steps as highlighted in the image below and discussed below the image.

1. Access Segment Search within the Tier 1 Tools on the main page.
2. On the resulting page, enter your kit number.
3. Select the number of matches you would like to see in the report. If you’re selecting all chromosomes (see step 5), you might want to initially limit the number of matches to between 1,000 and 2,000. If selecting a specific chromosome, then I would consider at least 3,000.
4. I leave the minimum segment length to 7 cM unless I later notice there are too many small matches at the segment location I am evaluating. Otherwise, 15 cM is an appropriate minimum size, but please review my earlier blog post about how smaller matches below 15 cM can be useful. Don’t ignore them as some smaller matches can be helpful while others can be “false” matches.
5. I recommend selecting the specific chromosome to which the genetic network is associated so your analysis is more focused. Select all chromosomes if you want to create a file for later analysis should your Tier 1 membership lapse.
6. If you enter a specific chromosome number from step 5, then enter the specific start and stop locations as this will return all matches that share a portion of the segment, which help focus your subsequent analysis. You can leave these fields blank if you would like to view the entire chromosome for record keeping purposes.
7. When finished, click the submit button. The report should take about a minute or two depending on how many chromosomes and matches are being evaluated.

A partial anonymized example of the Segment Search report is displayed below. It highlights the Gedmatch kits that match me on the same triangulated Hill genetic network segment presented previously for the MyHeritage example. Once you locate potential matches to evaluate based on a shared segment, take note of the kit numbers. Returning to the Gedmatch’s home page, you can use the “User Lookup” feature to find the match’s email address and gedcom (family tree) file if they uploaded one.

Conclusion

Expanding your search for additional matches on other DNA testing websites can help you build confidence in your observations in another testing website or find the one critical match proving your theory. Admittedly, it takes considerable effort to locate the additional matches and evaluate their trees and chromosome information. However, the payoff can be the difference in never making progress on a brick wall or resolving a mystery ancestor and progressing to next brick wall.

In Part 7 and final post of the Genetic Network blog series, I describe how to strategically progress from DNA analysis to documentary research. It will be posted on October 21. Review all previous posts in the Genetic Network series by starting with Part 1.

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