X-DNA: What is the minimum reliable cM to research? | Genetic Genealogy

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  • เผยแพร่เมื่อ 15 ธ.ค. 2024

ความคิดเห็น • 50

  • @sr2291
    @sr2291 3 ปีที่แล้ว +15

    I wish more of the DNA testing companies would report the X DNA results.

  • @suzannemcclendon
    @suzannemcclendon 3 ปีที่แล้ว +1

    I have an interesting puzzle with one of my DNA matches. She matches me through both my father and my mother. She has a 20+cM X-DNA match with me and my mother on the X, but doesn't have an autosomal match to my mother. She does, however, have an autosomal match to my father (and no X match to him). No names in her tree are familiar to me, so this is going to be a fun one to sort out.
    Also, it appears that my paternal X-chromosome has been passed down intact at least as far back as my 4th great-grandmother, through my grandmother's father, from her to her son to his daughter to her son to his daughter to her son to me. There is so sign of "interference" from the other half of the ancestor couples involved.
    Keep up the good work!

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  21 วันที่ผ่านมา

      Neat X chromosome. To get one un-recombined for that long would almost certainly have to go through father daughter a couple of times.

  • @roberthopgood1894
    @roberthopgood1894 3 ปีที่แล้ว +4

    where are the dna basics videos so i have a chance of understanding this

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  2 ปีที่แล้ว

      I finally made a basics video playlist. th-cam.com/play/PLcVx-GSCjcdnEg-YtkXA7Nj2YxxamaYKA.html
      But... X-DNA, mt-DNA, and y-DNA are not easy to learn. Instead, focus on autosomal DNA.

    • @roberthopgood1894
      @roberthopgood1894 2 ปีที่แล้ว

      @@FamilyHistoryFanatics thx

  • @jasonjoseph8700
    @jasonjoseph8700 3 ปีที่แล้ว

    Thanks for sharing something I totally didn't Know about, that part

  • @xxk3rd196
    @xxk3rd196 3 ปีที่แล้ว +1

    3:17 are you saying “you don’t inherit dna” fully or partially

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  2 ปีที่แล้ว +1

      Fully.

    • @xxk3rd196
      @xxk3rd196 2 ปีที่แล้ว

      @@FamilyHistoryFanatics thanks. I guess when you see a consistent 1% of a particular community eg. Greece Cypriot or Iranian… would you assume its 1/6 generation ancestors

  • @godisloveireland
    @godisloveireland 3 ปีที่แล้ว

    Enjoy your trip devon!

  • @vinicius.lavandoscki
    @vinicius.lavandoscki ปีที่แล้ว

    Would a 7.3 cM autosomal + 33 cM X DNA match be relevant on searching ? Since i'm adopted i think it might help me figure out my maternal line.

  • @lauraneville50
    @lauraneville50 3 ปีที่แล้ว

    excellent presentation-- thank you so much!

  • @jonathanlong5504
    @jonathanlong5504 3 ปีที่แล้ว

    I found a well-triangulated X DNA segment for a distant ancestor, and I am wanting to contact the other folks who appear to share at least part of the same segment (start or end). The triangulated matches do not share autosomal DNA, but I have connected their trees via X inheritance pathways. It seems that a 15 cM limit (and the required autosomal rule) would be too restrictive once you have identified the segment in this way. I recognize that most people won't have trees that go far back enough to confirm a connection, but I am concerned about avoiding false positives. Do you have a sense for what the limit should be to avoid that problem?

  • @sharonjacob4782
    @sharonjacob4782 3 ปีที่แล้ว

    Interesting Andy the only platform I am on that shows a X chromosome match is FTDna but it's always attached to an autosomal match. Perhaps I didn't catch it but did you state that the x chromosome division always happens as you demonstrated with the maternal x chromosome coming from grandparents always the female side donating 13 and 13 and none from the make side at that level? And that is how you can eliminate for sure that line of ancestors?

  • @LanceHall
    @LanceHall ปีที่แล้ว

    My cousin matches a 6th cousin on chr 1 (10cm), chr 2 (10cm) and chr 23 in two places (6.1 and 7.6). Yes, they would share X-DNA from the common ancestor. So, I assume this is a legit X-DNA match or a match on other lines not yet known?

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  ปีที่แล้ว

      The amount of X DNA shared is still quite low. I would have to find the common ancestor before I would say it is a "legit" match.

  • @lbfaith
    @lbfaith 3 ปีที่แล้ว +1

    How do I go about placing an female 2nd cousin (1C1R) adoptee that matches with a male using x dna? Or the chromosome browser?

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  2 ปีที่แล้ว

      The male has to be related to the female through the male's mother. Other than that, you can't glean much from what you have shared.

  • @jessikamoore5033
    @jessikamoore5033 ปีที่แล้ว

    I have a 20 some cM X match with the exact same mtdna number as mine at 23 and Me
    but she does not match my Mom's cousins with the same mtdna number, how is that possible?

  • @michaelwhalan9783
    @michaelwhalan9783 3 ปีที่แล้ว

    Four Geiszler X matches only at about 24cM on one segment each 23andme then one autosomal at 8cM on MyHeritage (they don't show X).

  • @LindaSchreiber
    @LindaSchreiber 3 ปีที่แล้ว

    I usually have a minimum of 20 cMs for someone with reasonable autosomal (25 or better).
    For someone with no autosomal and 35-50 on the X, I will at least do some looking.
    Some of those are id-able. But I don't drive myself crazy over them ;)

  • @seanoxton5572
    @seanoxton5572 3 ปีที่แล้ว +1

    I've seen the minimum amount of x chromosome explained in its significance but what about larger matches. I have a second cousin (according to 23 and me) who I have a 175 CM x match. Can anything be inferred by a large continuous segment?

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  2 ปีที่แล้ว

      On X- DNA it is very possible to get large segments with distant relatives.

  • @carmelmiller4165
    @carmelmiller4165 3 ปีที่แล้ว

    This is most interesting to me as I have an 80 cm segment shared by myself, mother and daughter. This is also shared by another lady with no autosomal connection. Where is the best area to look for a common ancestor?

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  2 ปีที่แล้ว +2

      X-DNA matches without autosomal connection can be several generations removed (in some cases beyong the expected records timeframe)

  • @suzannemcclendon
    @suzannemcclendon 2 ปีที่แล้ว

    With all of the recombination going on from generation to generation, is it possible to have absolutely no autosomal DNA from a specific 2nd great-grandparent?

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  2 ปีที่แล้ว +1

      No autosomal DNA from a 2nd great-grandparent? Yep. That's entirely possible. Which is why you want to test as many descendants of an ancestor as possible.

    • @suzannemcclendon
      @suzannemcclendon 2 ปีที่แล้ว

      @@FamilyHistoryFanatics Thank you. I was thinking that it could be possible, but wanted to be sure. I wonder if that is what is at play with my Maggie Robinson Williams, or if perhaps she wasn't really my 2nd great-grandma, but a step-grandma instead. Whatever is the case, still no luck with her. Thanks again. Have a blessed day.

  • @sheppeyescapee
    @sheppeyescapee 3 ปีที่แล้ว

    I'm fascinated by my mothers X chromosomes, On the dna painting on 23andme her maternal one is entirely British & Irish (English Mother) and her paternal x chromosome is mostly Chinese (Mauritian Creole father) I'm intrigued to figure out who the Chinese ancestor is/was and my mum has a bunch of Chinese matches on her paternal X but I don't think any are close enough to be of use.

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  2 ปีที่แล้ว +1

      That's definitely an interesting case. I would focus on doing autosomal DNA research first to find the clues you need to pair it with XDNA research.

    • @sheppeyescapee
      @sheppeyescapee 2 ปีที่แล้ว

      @@FamilyHistoryFanatics Her closest 100% Chinese match autosomally is 35cM and then above that it's all other Indian Ocean Creoles who are part Chinese. The main problem is lack of matches/close matches. We have one Mauritian close match (111cM) on Ancestry but she has 1 adopted grandparent and another whose name changed and nobody knows the previous name. The only shared match is with my mum's grand-niece so doesn't really reveal anything. Trying to persuade them to upload to myheritage which has a larger amount of Indian Ocean creoles to see if we have more shared matches there but they haven't.

  • @ericpham5198
    @ericpham5198 2 ปีที่แล้ว

    Can nitrogen content in the air affect our DNA like Fossil fuel may influent our consciousness greatly?

  • @mamabear52
    @mamabear52 3 ปีที่แล้ว

    Weirdest X match, my aunt shares 18cm on chrom 22 and 95cm on the X with a woman who is perhaps 2 generations different (the match is younger). I know where the X came from, her maternal great-grandmother, so her mom's dad's mom, she was born in the 1850s. I am not sure the transmission of the younger woman because she is adopted, but I know the family line they share, based on triangulation with a couple of dozen other matches.

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  2 ปีที่แล้ว +1

      With the autosomal match and the known X transmission line of one of the matches, you actually have a descent chance of solving this puzzle.

  • @gilgamew
    @gilgamew 3 ปีที่แล้ว +2

    I have 7 cM match on my X-chromosome with two persons (e.g., A anb B), with no autosomal match. But we triangulate! Also, me and person B form another triangulation group with person C - by 7 cM autosomal match without x-dna match. Is this a good clue or not?

    • @gilgamew
      @gilgamew 3 ปีที่แล้ว +3

      Another point is that me and all persons A, B and C share a common ancestral surname (Makarov). But X-chromosome is never transferred from father to son, as surname usually does. This is quite embarrassing

    • @lightyagami3492
      @lightyagami3492 3 ปีที่แล้ว +1

      @@gilgamew The only conclusion i can come to is that you ALSO have Makarov ancestors on your matralinial line somewhere.

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  2 ปีที่แล้ว +1

      The amount of shared cMs is rather small. I wouldn't focus on solving this puzzle until I've resolved how all of my autosomal DNA matches relate, isolate the maternal lines and then compare that with the XDNA matches. It's possible that these matches match further back in the generational family tree and autosomal DNA has not been passed to them but XDNA has.

  • @ericpham5198
    @ericpham5198 2 ปีที่แล้ว

    If we calculate all the way to beginning of humanity each one of us may had up to hundred thousand of relatives I other universe like tree , flowers or other living physical or spiritual

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  2 ปีที่แล้ว

      While theoretically that's a fun exercise, that's not how genetic works. th-cam.com/video/nlmK0X3I1Lo/w-d-xo.html

  • @RedRed-uj5ro
    @RedRed-uj5ro 2 ปีที่แล้ว

    FIBONACCI sequence in the male line.

  • @alanheadrick7997
    @alanheadrick7997 2 ปีที่แล้ว

    I just received a reply to my comment and my comment is gone. So I have an answer to a question I forgot, DOH!

  • @thelmahunter4305
    @thelmahunter4305 2 ปีที่แล้ว

    So what happens when you just have a X only

    • @FamilyHistoryFanatics
      @FamilyHistoryFanatics  2 ปีที่แล้ว

      An X only match would be 3rd cousin or more distant. If they were 2nd cousin or closer, they would share autosomal DNA as well.