DNA Matches by Testing Company

Ancestry has recently announced that their DNA database now includes over 6 million individuals.  As Ancestry has the largest autosomal DNA database they are happy to announce these milestones, but accurate information on the database size of the other DNA testing companies is more difficult to obtain.

To provide some idea of how many matches you can expect if you test with the various DNA testing companies, I have compiled the data for my own DNA and my wife's DNA into a chart to show how many matches the major DNA testing companies have identified for each of us, and within that list of matches, how many matches I have been able to confirm match my paper research.

As Ancestry has the largest database, you would expect that it would generate the largest quantity of matches.  This is confirmed for both Marlene's sample and my sample.

You would also expect that Ancestry would generate the largest number of matches confirmable by paper research.  This is true for my sample, and would also be true for Marlene's sample, if she did not have a group of 5 matches on 23andMe that are all siblings / children of those siblings, which skews her data.

But the percentage of Ancestry matches that have been confirmed against paper research is certainly not as great as the percentage that have been confirmed for our samples on 23andMe and Family Tree DNA.  There are a number of reasons why this could be -

• With such a large number of matches on Ancestry, I simply have not investigated enough of them to confirm the match.
• Ancestry uses a lower threshold of the amount of shared DNA that constitutes a match, than the other testing companies do, but those more distant matches are more difficult to confirm against paper research.
• For those Ancestry users who have public family trees, I cannot view their family tree, as I do not have a paid monthly subscription to Ancestry's historical records service, making it more difficult to identify a common surname or even a region where our common ancestor may have lived.
• Ancestry does not identify which segments are shared on which chromosomes (23andMe and Family Tree DNA do), making it more difficult to see which ancestral line we may connect on.

My advise continues to be to test with as many DNA testing companies as you can afford, as they all will generate matches not found on the other testing companies' sites, but regardless, upload your DNA result to GEDmatch.com.

GEDmatch facilitates comparison of DNA samples from multiple DNA testing companies on one site, but requires those who have taken a DNA test to upload their raw DNA data file to the site (a free service).  GEDmatch limits the number of matches that are displayed to 2000, so you may not see a distant relative in your list of matches, if the amount of shared DNA puts them below number 2000 in your list of matches.

I complied the chart below to show the percentage of our GEDmatch matches that come from each DNA testing company.  More than half of our matches on GEDmatch are from Ancestry, but not the 90% that you might expect given the number of matches in each company's database.  

My best guess is that a lot of people take an Ancestry DNA test to obtain their ethnicity breakdown, but do not pursue searching for DNA relatives.

I will update these charts at some point in the future, perhaps when Ancestry hits 7 million DNA samples, but meanwhile I will continue trying to confirm the ancestral connection for our DNA matches from all testing platforms.

Which Autosomal DNA Test Should I Take?

My first autosomal DNA Test was with 23andMe in 2015.  Since then I have taken advantage of the free import of 23andMe raw DNA data to MyHeritage, have done a test with AncestryDNA, and most recently have used the FamilyHistoryDNA autosomal transfer program.  So which test would I recommend?  Below are my personal opinions of each testing company, and my recommended testing sequence.

Ancestry DNA

+  The largest autosomal DNA database

+  Identification of others who match you and someone else

-  Does not identify which segments are shared with others, and there are no DNA tools to work with

-  If you do not have a paid subscription to Ancestry, then DNA matching functionality is somewhat limited

23andMe

+  The second largest autosomal DNA database

+  Identification of Y and Mt-DNA haplogroup (at a broad level)

+  Shows the percentage of DNA shared with others, which segments are shared with others, and has basic tools to work with, including a chromosome viewer (up to 5 people at once)

+  If a parent has also tested, matches can be split between paternal and maternal lines

+  You can update the predicted relationship to the actual known relationship, without a family tree

FamilyTreeDNA

+  Predicted relationships can be confirmed by linking matching individuals to your family tree

+  Once a few matches from both sides are confirmed, the system predicts paternal and maternal line matches, without having a parent tested (gets better as you confirm more matches)

+  Shows the amount of shared DNA, and allows viewing of the matching segments of up to 5 people

+  Good filtering and sorting of matches

+ A FamilyTreeDNA test sample can also be used for Y and Mt-DNA testing

+  Low cost (US $19.00) transfer of raw autosomal DNA data from Ancestry and 23andMe (cannot be used for subsequent Y or Mt-DNA tests)

-  Third largest autosomal DNA database 

My Heritage DNA

+  Free transfer of raw DNA data (limited time offer) from other testing companies

+  Shows the percentage of shared DNA and the number of shared segments

-  The smallest autosomal database, of the 4 major DNA testing companies (but should increase rapidly if people take advantage of the free transfer from other companies)

-  Does not show which segments are shared with other users

-  If you do not have a paid subscription to MyHeritage, then DNA matching functionality is somewhat limited

If I had the money, I would take every available test with every testing company, to maximise the chance of finding new DNA matches, which help to confirm the researched family tree.  But recognising that very few of us have unlimited funds, I would recommend the following sequence -

1. Test with either 23andMe or Ancestry (largest databases provide the most exposure)
2. Upload your raw DNA data to GEDmatch, to utilise their tools and to facilitate matching with users across different testing companies
3. Purchase the low-cost autosomal DNA transfer to FamilyTreeDNA
4. Create a family tree on FamilyTreeDNA, either by manual entry or by GEDCOM import from an existing family tree
5. Take advantage of any other free or low-cost DNA data transfers from other testing companies
6. Once you are totally hooked on genetic genealogy, take a Y-DNA (paternal line) and / or a Mt-DNA (maternal line) DNA test, to learn about these two lines in more detail

 The number of people taking autosomal DNA tests seems to be growing exponentially, so you can expect more and more DNA matches  as time goes on.

Good luck!