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Klinefelter's (XXY)

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  • Klinefelter's (XXY)

    I recently found out that I have the XXY chromosome type and once the shock of it had worn off the genealogy nerd in me started to wonder what it would mean for an X-chromosome test.

    Of course, it totally depends on whether my extra X chromosome comes from my mother or my father, but I would like to know two things:

    1) Would the team at FTDNA be able to analyse such a sample? Would a test have to be dealt with in a special way?

    2) Will it be in any way more useful/insightful about my ancestry?

    I look forward to hearing more! Thanks

  • #2
    If you can, phone Family Tree DNA at +1-713-868-1438 during their business hours.

    FTDNA does not monitor the forum, so they would not see your questions asked here.

    W. (Mr.)

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    • #3
      I assume you're thinking about taking a Family Finder test, which includes the X chromosome? The actual test results would not be a problem. They just report whatever alleles are observed for a particular SNP. You would likely be heterozygous for many SNPs, since the two X chromosomes would not be completely identical. FTDNA doesn't use any Y SNPs for the FF test, so they might not even observe the XXY scenario. But as dna said above, you can contact FTDNA to see what they have to say.

      As for your question about ancestry, you have doubled your chance of matching with someone in the X line. If you can test some other relatives, you could probably figure out if the extra X was maternal or paternal in origin.

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      • #4
        Ann, I was afraid that during QC the X chromosome test results might be repeatably rejected, if FTDNA did not know about XXY.

        @plgenes, if it is not convenient for you to phone FTDNA (overseas, working etc.), I can phone them and ask about XXY without mentioning you.

        W. (Mr.)

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        • #5
          KLINEFELTER - XXY = No Y STR Result?

          You may or may not be successful regarding a YSTR result depending on whether or not you do actually have Klinefelter or rather a mosaic Klinefelter profile instead. Often, but not always, there is a side effect of infertility although those with the mosaic type may not have XXY in all cells.

          If you order a Y37 - Y67 test the result may return as failed, and is then re-run -however if the sample continues to fail then FTDNA would usually notify you that a result was not possible. If you order the Family Finder autosomal test you should definitely receive excellent results as the autosomes are not dependent upon the allosomes (sex chromosomes) in order for a result to eventuate.

          So, you have the potential to learn further information regarding the extent of the Klinefelter syndrome you have inherited by ordering both of these tests- Family Finder and YDNA . The y12 might be the least expensive option actually rather than the full gammit of 37 or 67 markers. You just need to determine if there is a possibility of a mosaic profile initially.

          Alexandrina

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          • #6
            Originally posted by Alexandrina View Post
            You may or may not be successful regarding a YSTR result depending on whether or not you do actually have Klinefelter or rather a mosaic Klinefelter profile instead. Often, but not always, there is a side effect of infertility although those with the mosaic type may not have XXY in all cells.

            If you order a Y37 - Y67 test the result may return as failed, and is then re-run -however if the sample continues to fail then FTDNA would usually notify you that a result was not possible. If you order the Family Finder autosomal test you should definitely receive excellent results as the autosomes are not dependent upon the allosomes (sex chromosomes) in order for a result to eventuate.

            So, you have the potential to learn further information regarding the extent of the Klinefelter syndrome you have inherited by ordering both of these tests- Family Finder and YDNA . The y12 might be the least expensive option actually rather than the full gammit of 37 or 67 markers. You just need to determine if there is a possibility of a mosaic profile initially.

            Alexandrina
            Wouldn't a mosaic have some XXY cells and some XY cells? It would seem that having the same Y in all cells would not cause a failure of the Y STR test but maybe there are problems that I am unaware of due to the duplication of the X. I know nothing about the steps involved in purifying the Y out of the cell.

            Let us know how it turns out if you order the Y STR test.

            I would also be curious about what the X looks like in the raw data in a Family Finder test. It might look like a test a female gets, one X from the father's side and one X from the mother's side. But there is a higher chance both Xs would be of maternal origin and I wonder how these would match with other relatives.

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            • #7
              @plgenes

              I would tell FTDNA that you have XXY.

              If not by phone, then after having a kit number by using the contact form using (probably) "Interpretation of Results" category.

              W. (Mr.)

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