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Who to test on Big Y

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  • Who to test on Big Y

    If I were to do a Big Y test who should I upgrade and would it matter. I have my Dad, Myself and my son all on FTDNA. Would it be better to test my dad the oldest or my son the youngest? My guess is that it would not matter but I wanted to hear from some experts.


  • #2
    All three will match very closely.

    If it were me, I would test the father. He is the one closest to the "origin" if you are trying to trace your roots. There is a small chance that mutations have occurred in your family even within the last several generations. The chances are slight, but you can avoid that by testing the oldest individual. Also you have the advantage of the DNA being stored (if it isn't already) and that opens the option of post-death testing. The odds are the oldest in the family will pass away first and you want to keep your testing options open especially if new DNA methods appear with future technology advancements.


    • #3
      The son!

      If not too late, then test your son - he will have the maximum of novel SNPs (+2 generations from your father). You can always test your father and yourself for your son's novel SNPs at afterwards and see if he/you have them too. You can not do the opposite!


      • #4
        Another thing to keep in mind is you may have to test
        two (mayber more?) men with Big-Y to get a consensus on some SNPS
        Here is my story.
        I have a Big-Y test along with a cousin (different surname
        due to a 1756 orphan NPE) We have an STR match at 111
        along a family finder atDNA match. He is a 5th cousin.

        Per FTDNA we do NOT have a Big-Y match. So I decided to have my brother tested.
        Thus I now have Me(M) Brother(B) and Cousin(C) results
        from FTDNA web site
        On the compare page M vs B is in position 11 there are
        ten above us.
        Compare results:
        We are all R-z2563 with over 400 Big-Y matches
        M vs B 2 Non-matching known SNPs M367 L362 Shared Novel 35
        M vs C No Match
        B vs C 3 Non-matching known SHPs Z2001,L1008,L1089 Novel 33

        It is my theory that FTDNA test got All or most of those
        5 SNPs wrong in my results. That would give me
        a "Non-Matching Known SNP" difference of 5 between M & C which is why M does
        not match C on the FTDNA web pages.
        I think the best way to look at matches is to sort them
        on descending Shared Novel Variants.
        NOT on ascending Known SNP difference as FTDNA default page show it.
        Any others with thoughts on this?
        Do we have any data on the possible rate of false calls in the Big-Y results?


        • #5
          JSW, Have you had the 3 Big Y results analysed by Yfull or FGC. Or Alex Wiliamson if your R-L21.
          They usually do a better job than FTDNA.


          • #6
            Re Outside FTDNA analysis
            My kit has been analyzed by YFULL the other two have
            not -that is on my longer term "to do" list

            Yesterday I downloaded the list of Novel Variants for the
            three kits. There are 35 for each for each.
            The compare shows the following:
            The three kits have 31 Novel Variants in common
            Cousin kit has 2 SNPs not in the other two
            Cousin Kit has 1 SNP in Brother not in my kit.
            Cousin kit has 1 SNP in my kit not in Brother
            Brother and my kit have 3 SNPs not in Cousin.

            FTDNA only reports novel variants that are of
            "High" Confidence level.
            That tells me we do know know for sure about the
            mismatches. For example in this case:
            Cousin Kit has 1 SNP in Brother not in my kit.
            Is the SNP in question in my data recorded
            with "Reference" value and "High" confidence
            Or could it just be the confidence is not "High"
            and thus not reported?
            I will have to look at the other files to see.
            I do not know if that is in the VCF file
            or not I know it is in the BAM file
            and I have that so I will be able to
            review that one SNP and report back here.


            • #7
              I've got the same question. I've tested myself and a maternal uncle via Big-Y. I've done FF and MTFull on my father but no Y-testing since I expected the results to be identical to my own. I'm just wondering that since there's a sale going on whether it would be worth doing a Y-12 and a Big-Y on my father. This testing would get me a free upgrade to Y-111 and I'd have Big-Y for the additional STR values that they'll be doing next year but is there any value in it? My gut feeling is that there isn't because the testing will probably show the exact same results for both tests.

              My thoughts at the moment are that FF tests for more people are the best use of funds.


              • #8
                I have yet to get my Big-Y back after the Oct 10 up grade.
                But before that Big-Y between myself and my brother showed
                3 SNP differences
                There may be some value in father/son test in the old system
                I wish I could tell you how it is now.
                My brother's test came back 4 week ago


                • #9
                  Originally posted by JSW View Post
                  Any others with thoughts on this?
                  Do we have any data on the possible rate of false calls in the Big-Y results?
                  Its very small compared to 10 million, or the current
                  300,000 or so on their list.

                  In my project we are averaging 6 bogus SNPs listed as
                  Novel Variants for each person. That's a huge average
                  as far as matching goes.

                  We are averaging 4 bad known SNPs per person. However,
                  some are more.

                  These are usually above 50,000,000, in the centromere,
                  or inside STRs or pseudo STRs.

                  In other words, they've got problems.

                  There seem to be patterns in this however ... which means
                  that the patterns themselves may actually be reliable!

                  I've found 3 very reliable structural variants by examining
                  bogus SNP patterns. These determine a very important clade, and even better, they can be RELIABLY measured using the new VCF files! To do this you need lots of test results with BAM files to stare at (VCFs and the online browser would not have done the trick.)

                  ************************************************** **

                  Two VERY important new BigYs appeared today with piles and
                  piles of bad SNPS and three very useful, very important new SNPs
                  on each.