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  • DYS448/ CDY

    Can someone explain the DYS448 and CDY markers? I have a close match at 67 marker level. The only markers we differ in are the DYS448 by 1 point and the CDY by 1 point on CDYb. My match is tested at 111 w FF and I only at 67. I have ordered FF as he is (NPE). I am not upgrading to 111. I will do Big Y next year. I am thinking he is most likely a fifth to 7th cousin.

  • #2
    Can't speak to DYS448, but CDY is a palindromic marker linked with two other markers(DYS459 and DYS464). FTDNA's own information(Which I can't find right now) has previously claimed those markers are included because of their tendency to mutate. So CDY changing by one isn't too big of a deal by itself.

    In my case, against my own father no less, we had a mismatch on CDY(c), and a copy number change on DYS464 putting me at GD2 in relation to his results.

    Other information for you:

    Note this is discussing GD2 @37 markers, not 67.

    A 35/37 match between two men who share a common surname (or variant) means they share a common male ancestor. The mismatch is likely within the range of most well-established surname lineages in Western Europe. It is most likely that you matched exactly or closely on previous Y-DNA tests, and the mismatch is within DYS439 or DYS385, DYS389i, 389ii, DYS458, DYS459, DYS449, DYS464, DYS576, DYS570, or CDY.
    Or the 67 marker version:
    GD1 or 2:
    A 65/67 or 66/67 match between two men who share the same surname (or a variant) indicates a close relationship. It is most likely that they matched 36/37 or 37/37 on a previous Y-DNA test. Very few people achieve this close level of a match. All confidence levels are well within the time frame that surnames were adopted in Western Europe.
    GD3 or 4:
    A 63/67 or 64/67 match between two men who share the same surname (or a variant) means that they are likely to share a common ancestor within the genealogical time frame. The common ancestor is probably not extremely recent but is likely within the range of most well-established surname lineages in Western Europe. It is most likely that they matched 24/25, 36/37, or 37/37 on previous Y-DNA tests, and mismatches are within DYS458, DYS459, DYS449, DYS464, DYS576, DYS570, and CDY.
    Keep in mind mutation is random, and while the above mentioned markers are particularly noteworthy for their tendency to be unstable, other markers do change randomly as well. So seeing GD2 with one of the above makers + another (DYS448 in your case) doesn't rule out a closer relationship. (Such as my being GD2 with my father) But with random events being random, some lines are reported to be unusually stable on the STR marker front, so a GD2 match could turn out to be much further back than the statistical averages/estimates suggest.


    • #3
      A specific marker difference does not really have any relevance to what it means other then some are faster mutation rates then the others.
      I believe 111 markers level tends to have the fastest mutation rates, and 12 marker level the slowest mutation rates.
      As mentioned mutations happen at any time, one can even have multiple marker mutations with in a single father to son transmission.

      My father and his paternal 1st cousin are a GD of 4 at the 37 and 67Markers levels.....3 markers different, with one being a two step difference. (DYS389ii, CDY, and 2step difference on DYS576)
      My Uncle to same cousin has only a GD of 3, all the same marker differences above but DYS576 has only a difference of 1 (due to this my father and his brother are a GD of 1 to one another)
      Last edited by prairielad; 6th February 2019, 02:48 PM.


      • #4
        Thank you both for the information. So. It could be a relatively close match. Or it could be a farther than 5th cousin match. My match has done FF. I initialy did not and wasnt going to until I found out he was an NPE. I just want to help him find his dad if we can and if not at least find which line he descends from. Now I am waiting in my FF results. Hopefully he shows in my FF matches and we will have a better clue as to if he is a cousin, nephew, uncle, etc.