23andMe and haplogroups

+5 votes
I've been trying to get the funds together to have my brother take a Y-DNA test with Family Tree DNA, but in the meantime, he bought a 23andMe test for himself, because his girlfriend took a 23andMe test and he thought it was fascinating.

He shared his results with me, so now I know the haplogroups that 23andMe assigned to him. The maternal haplogroup was very broad, as I'd expect - H1. But the paternal haplogroup seemed a lot more specific than I was expecting - R-Z28496. (But maybe it's not that specific. I haven't research Y-DNA much, since I haven't had access to the test yet.)

What, if anything, like I do with this information? Is it likely to be correct? Would he get some other haplogroup entirely if he tested with Family Tree DNA? If he was willing to share his DNA results on Wikitree, could the haplogroup information be useful at all? Both of our parents and our maternal grandmother have already shared their autosomal DNA information with Wikitree, so his (and my) autosomal information is less useful. But can we do anything useful with the haplogroup information from 23andMe until I can afford the Y-DNA test?
in The Tree House by Jessica Hammond G2G6 Mach 3 (30.2k points)
retagged by Steve Schmidt

2 Answers

+9 votes
Best answer

Hi, Jessica! The good news is that your brother's R-Z28496 (also known as FGC22592) designation is very likely to be completely accurate. The also good news is that if you have a genealogical hypothesis that a male in your tree does not match the hierarchy down to R-Z28496 (which, working its way upward, would be < FGC22940 < Z142/S11 < Z49 < L2/S139 < U152/S28 < P312 < L151 < P310 < L51 < L23 < M269) then--ta dah!--the hypothesis is correct. But the bad news is that R-Z28496 probably branched off from FGC22940 over 2,000 years ago, maybe as long as 4,000 years if guestimating from Yfull.com.

With close to 200,000 yDNA defining SNPs (single nucleotide polymorphisms) identified, and many of those added to the taxonomy just in the past several years, yDNA haplogroups can get a little...complicated. Unless a haplogroup designation--as specified by a particular SNP--is one that only recently arose (and these are almost always identified only by full-sequence Y-chromosome testing like FTDNA's Big Y-500) it really isn't useful as positive evidence for genealogy. It can be great at disproving a relationship, and it can also provide clues for continued searching, but there's no "matching" involved at that level.

The typical yDNA tests at FTDNA look at STRs, short tandem repeats, and don't test SNPs at all. These are like copy machine stutters where the same sequence of a few alleles get repeated several times. Unlike a polymorphism, these happen much more frequently and the differences--or similarities--between values can put things squarely in the genealogical timeframe. These STR tests (you'll see them called Y-37, Y-67, and Y-111 tests) don't actually examine any SNPs at all. They predict a haplogroup based on the results of the STR values.

Companies like 23andMe and Living DNA don't do specific yDNA or mtDNA tests like FTDNA, YSEQ, and others do. The marketing is a tad misleading when they say, for example, that they perform three tests. It's all one test using what's called a microarray BeadChip that's partially customizable. The test looks only at SNPs, not at STRs, and the SNPs are targeted by the way the chip is programmed (has to do with the way nucleic acids bond selectively with one another). Some of the chip's programming targets SNPs in the Y-chromosome.

Voila! That's how an autosomal DNA test can accurately return a yDNA (and mtDNA) haplogroup. However, it's all about the programming. The chip can look only at what it's programmed to look at, so the haplogroup can only be defined to the extent of that programming. Where the Big Y test tries to look at as many of the Y-chromosome's 58 million base pairs as possible and can find novel or unique SNPs that might just this generation be splitting off on their own, the chip-based test can only look at the few thousand base pairs it's programmed to locate. But as far as it goes, it's quite accurate.

Your brother, as am I, is among one of the most common yDNA subclades in the world, R-M269. That's why 23andMe returned a fairly deep result for him: programming the microarray chip to look levels deep in M269 makes numbers sense. Others who are in less common haplogroups will see results only at a higher level. As an example, a man in haplogroup E might get a result that shows E-M44, which is equivalent to E1a1, only three levels deep in the E phylotree.

P.S. Good on ya getting your parents and a grandmother tested early. So many folks taking autosomal tests right now start out interested only in the ethnicity/admixture, and only later come to understand how irreplaceable to genealogy are results from earlier generations.

by Edison Williams G2G6 Pilot (231k points)
selected by Jessica Hammond
The only thing I would add to what Edison has said, is that testing at FTDNA would also give you a match list for your brother. If you have a particular theory about your paternal line that you want to find evidence for or against then it may be worth considering. If you are not working on a specific hypothesis then this may not be the best use of your DNA funds.

"If you are not working on a specific hypothesis then this may not be the best use of your DNA funds."  I agree with Lynda's statement.  I didn't see any likely matches to a 23andMe haplogroup in FTDNA's Y-DNA projects.  I asked a couple of the administrators multiple questions whether there would be any benefit to testing.  I was just advised to test.  I finally did during the sale.  There were no close matches, not even anyone distant with Scandinavian ancestry.  Maybe a match will test one day, but I didn't learn anything useful for now as the 23andMe haplogroup was more specific than FTDNA's.  I suppose that someone has to be the guinea pig.  

Thank you for the very thorough answer! That's a lot to process, and I think I'll be going back to it when I'm trying to make a decision about when and whether to get the FTDNA test.

For now, I'm understanding that I can use to haplogroup information to disprove a connection, but not to prove a connection. Have I got that right? (Or, at least, have I got that right in a probably overly simplified way?)
+6 votes
1.  Whatever Edison says

2.  Whatever Edison says

3.  Whatever Edison says

4.  Whatever Edison says




473.  Yes, posting the 23andMe haplogroups on Wikitree can be useful.  FIRST, you will need to get your brother to join Wikitree, or you can create a profile for him and invite him to assume ownership of his profile.  HE, and only he, can then add his DNA tests.  Although there is a section to add the haplogroups when entering a 23andMe auDNA test, that info will not propagate.  He will need to add them under 'Other yDNA' and 'Other mtDNA'.  This will then propagate to all patrilineal and matrilineal ancestors respectively.  I've found the 23andMe haplogroups very helpful on multiple occasions to confirm that I have the correct lineage for an auDNA match.
by Kerry Larson G2G6 Pilot (113k points)

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