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Updating/Changing (?) of terminal SNP

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  • Updating/Changing (?) of terminal SNP

    My BigY result classify me as Hg N-Y17416. Among my 4 “bottom step matches” were 3 with an additional mutation, Y17415. Last week FTDNA changed/updated one of them to Y17652. Looking at the FTDNA phylogenetic tree – on my account - the Y17415 branch is the one below mine, but among the 9 “More” listed SNP they have Y17652.
    On the other person’s tree FTDNA call this branch Y17652 with Y17415 in Blue. Does this imply that FTDNA have had second thoughts about the quality off the initial Y17415 interpretation? On the “step” results however he is listed as Y17415, as is the YFull result.

    How should we interpret this?

  • #2
    No one with any suggestions?

    Anyway, I finally managed to access the FTDNA Big Y500 SNP file for my match cousin, and he is positive for all SNPs for the Y17415 branch, but not actually for Y17415! On YFull, using the VCF file from FTDNA, he is positive for all SNPs for the Y17415 branch, including Y17415, all at 5* quality. I can only explain that by suggesting a matching algorithm mistake from FTDNA.

    Comments, suggestions, etc, please.


    • #3
      The called results could be different from what was expected due to quality, and corresponding coverage, differences between the initial samples. Looking at the the VCF files should show whether there was a significant difference in the quality of the calls. Viewing the BAM files won't provide much more detail over what is listed in the VCF file.

      IF the variants are important to establishing the structure then acquiring individual test results, if they are individually testable, will be the best way to answer the question.


      • #4
        Thank you wkauffman,

        I have asked the tester to check with FTDNA first to see if they believe their analysis is correct. If that is positive we will have to look at the VCF files ourselves as you suggest.