Wednesday, March 25, 2015

Getting extra out of 23andme and AncestryDNA tests: Y SNPs

After learning from the ISOGG website ( that both 23andme and AncestryDNA tests include some Y SNPs, I did some investigations to see what we might get out of those results.

23andme Haplogroups and SNPs

First, 23andme gives outdated haplogroup assignments, but by looking at the raw data, you can learn which SNPs they have tested. This turned out to be very helpful in evaluating an important lead. I had found a 12 for 12 match based upon FamilytreeDNA STR (single tandem repeat) testing with someone with the surname Morford. Because we had strong autosomal DNA matches with Morford descendants, and because the Morfords in question lived close to my Long ancestors in Greene County, Pennsylvania, I am pretty confident that we have a genetic connection to these Morfords.

It turned out the Morford descendant had done additional SNP tests that placed him in haplogroup R-P312. I looked at my dad’s 23andme results, I saw that he had tested positive for SNPs showing that he was positive for U106 and beyond that, L48, while being negative for L47. Because R-U106 and R-P312 are mutually exclusive haplogroups, we apparently could not be a match despite sharing 12 STR markers in common. So the search for the patrilineal ancestor continues! However, by leveraging the 23andme results, I was able to learn which specific additional SNP I could test to best refine my haplogroup.

I also learned that another Long cousin was assigned by 23andme to a slightly different haplogroup than my dad, who had an extra “d” at the end, indicating a slightly more refined haplogroup. The difference, it appears, is that the cousin probably had a “no-call”. Beware that such subtle differences can arise due to methodology not genetics.

Comparing AncestryDNA Y SNPs

Next, I explored Ancestry DNA, where two Barmore cousins had results. One of them had done a 12 marker Y test at FamilyTreeDNA, which placed him in haplogroup J2a1h. We wanted to confirm that the other Barmore cousin matched his Y DNA. I was pretty sure he would, because the two were matches at AncestryDNA (and GEDMATCH, based on autosomal DNA). After a query to CeCe Moore, I learned that Ann Turner had created a spreadsheet tool for exploring Y SNPs from AncestryDNA. I downloaded the spreadsheet from, copied in the raw data. The results showed that the cousin had 26 positive SNPs with haplogroup associations. Most significantly, they included 4 SNPs for which he tested positive that would place him in J2a1h2a1. This seems to match the Barmore cousin with the 12 marker result. This seemed like pretty convincing evidence that the two cousins indeed shared Y DNA, and allows us to focus on more detailed STR or SNP testing in lieu of spending money on another basic Y test.

Thanks to CeCe, Tim Janzen, and the team managing the U106 haplogroup project for answering my questions about how to get a bit more mileage out of my Y results!

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