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  • Help Understanding

    Hi
    I'm a complete newbie to DNA. My grandmother has done the Family Finder test, and there is a match to a man which has a possible relationship of 1st-3rd cousin. It says they are X-match. What does this mean? Does this mean he is related to my grandmother on her mother's side?

    My goal is trying to find the common relation between this man and my grandmother.

    What I'm thinking so far is that his X he got from his mother and my grandmother has a mix of her mother and father's X. So even though they have an x-match, there is no way of telling if this man is related to my grandmother through her mother or father.

    Please let me know what further information I should share. I wasn't too sure what would or wouldn't be relevant.

    Thanks in advance.
    Last edited by rclarke; 21st January 2017, 12:43 AM.

  • #2
    How long is the X-DNA segment that they share?

    The best way to try to work out the relationship is by sharing what you do know about her ancestry, preferably on a tree. What I sometimes do, because some people find trees confusing, is write in the e-mail a little about the gt-grandparents of the person - such as Samuel X, born in Birmingham, England in 1848, son of X and Y, his mother died in 1850, emigrated with father and siblings to whereever in 1852 etc. It fills in the gaps more than a tree which on FtDNA just has births and deaths and nothing in between. I also (if I have that information) state any other ancestral names up that line. Names, dates (even approximate ones) and locations are the best way to work out a connection.

    Little pieces of info can help - so if his mother died in 1850 and your match thought their ancestor born in 1851 could be a sibling...well, that wouldn't fit would it.

    I have such an e-mail saved for each kit I manage. If I think I know where the connection lies I might add extra info about that branch.
    Last edited by ltd-jean-pull; 21st January 2017, 01:00 AM.

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    • #3
      Originally posted by ltd-jean-pull View Post
      How long is the X-DNA segment that they share?
      Many thanks for the quick reply. I'm not sure how to answer this, but I hope this is helpful. This is the information from the chromosome comparison:

      CHROMOSOME,START LOCATION,END LOCATION,CENTIMORGANS,MATCHING SNPS
      X,32309088,42592114,17.78,1375
      X,32309088,42592114,17.78,1375
      X,44026336,69689573,18.17,1850
      X,44026336,69689573,18.17,1850
      X,124911727,133812769,7.33,950
      X,124911727,133812769,7.33,950


      The man in question has no information about his ancestors as he was adopted, this is why I'm trying to figure out what side of my grandmother's family he may be related to. Which led me to question what the X-match may mean.

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      • #4
        Originally posted by rclarke View Post
        Many thanks for the quick reply. I'm not sure how to answer this, but I hope this is helpful. This is the information from the chromosome comparison:

        CHROMOSOME,START LOCATION,END LOCATION,CENTIMORGANS,MATCHING SNPS
        X,32309088,42592114,17.78,1375
        X,44026336,69689573,18.17,1850
        X,124911727,133812769,7.33,950



        The man in question has no information about his ancestors as he was adopted, this is why I'm trying to figure out what side of my grandmother's family he may be related to. Which led me to question what the X-match may mean.
        Edited out doubles (Bug in FTDNA chromosome Browser download)

        Match will be through your matches mothers line, but it can be either of your grandmothers lines.

        What about autosomal, what is the total autosomal amount?

        The following has a chart which you can use a guide to help narrow down possible relationship level based on cM amount (autosomal only, X amounts does not get included)
        Code:
        http://thegeneticgenealogist.com/2016/06/26/update-to-the-shared-cm-project/

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        • #5
          Thanks for the link prairielad

          Shared Centimorgans 283
          Longest Block 41

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          • #6
            This gentleman is probably your grandmother's second cousin, based upon the 283.

            So he shares great grandparents with your grandmother. Your grandmother has 4 sets of great grandparents and at this point, three sets are all potential MRCAs. You can rule out her great grandparents based upon her father's father's parents. You should print out the two fan charts here
            http://thegeneticgenealogist.com/200...-x-chromosome/

            Because your match is a male, it cannot be through his father's side. Must be through his maternal side. If he has no information then its going to be tough to narrow down.

            The next step would be compare your In Common Withs and see what is shared there. Not usually obvious but you might get lucky. Might need to look at trees here or Ancestry.com.
            In Common Withs are based upon autosomal, not X, so that shifts your emphasis back to autosomal.

            Load results to GedMatch. X tools are better there.

            And my disclaimer is that none of the above is guaranteed. The X DNA is rather irregular so there are no hard facts and rules here. Just a lot of "Shouldas". My third paragraph actually is pretty factual, but the first two are definitely fingers crossed.
            Last edited by mabrams; 1st February 2017, 03:54 PM.

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            • #7
              Originally posted by mabrams View Post
              This gentleman is probably your grandmother's second cousin, based upon the 283 (centimorgans).
              We should also entertain the possibility that instead of 2nd cousins, the match could involve 1st cousins twice removed, or half first cousins once removed. Either of those relationships would have similar expected centimorgans matches. Therefore it would be interesting to know the ages of the grandmother and her match. If they were about the same age, then 2nd cousins would be more likely. If there is 50 years difference, then 1st cousins 2x removed would be more likely.

              Also like you mentioned, it is a good idea to search matches in common with the man to see if any surnames or people are recognized among the matches in common. To do this, go to your family finder matches. Tick the box next to the person you want to compare. Then click on "In Common With". This will show a list of people who match both you and one of your matches.
              Last edited by Dabney Carr; 13th February 2017, 02:55 PM.

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