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General => The Common Room => Topic started by: dovecote on Friday 24 September 21 22:28 BST (UK)
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I have recently received my DNA results which shows my closest match being with a half-aunt( known fact) suggested as being a first cousin or a Gt Aunt. Can anyone explain why that may be?
Thank you
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Might I suggest you move this to the Ancestral Family Tree DNA Testing forum? You may get a broader response that way.
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DNA is not exact- they cannot predict a precise relationship between two people based on common DNA, only a range of possible relationships for the results. This gets less reliable with more generations of separation and the two testers share less and less DNA. You'll find that sometimes even if you match with two full blood siblings on another side of the family they might not show up with the same predicted relationship to you because they've inherited different sections of parental DNA. DNA is quirky like that.
As far as your aunt is concerned a first cousin prediction is not that far out, especially since she shares only one parent with your side. That kind of thing pushes the prediction out slightly because you match her closely, but not as closely as if she'd been a full aunt. As such, the goalposts have been moved a degree outwards and you have suggestions for a marginally more distant relationship.
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Ancestry will use the value to suggest various relationships from available data.
If you go to this site
https://dnapainter.com/tools/sharedcmv4
and put the total DNA you share with your half aunt in the top box, it will show the various relationships you could have with that value.
A half aunt would probably be between 492 and 1312. This amount could also be one of the relationships that you list. By coincidence, my great or grand nephew and I share 1100cMs so, without knowing the actual relationship, they could suggest that I am his half aunt, etc.
Gadget
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It just guesses a relationship based on the cM shared. I have a half aunt on Ancestry which like you I already knew. But Ancestry’s suggested relationship gave a different relationship. You can change it though as I said it’s only Ancestry suggested the relationship based on the DNA shared
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I have a similar case but further up a line where actually comparing a half great.with.a second cousin
Because although the great aunt only shares one great grandparent with me and the second cousin shares two
The great aunt s other parent is also connected to my family. Thru a different line .It would be interesting to know how strong your half aunts matches are to.your first cousins
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Thank you everyone for your help.
I did as suggested by Gadget entered total DNA of 1030cm which confirmed
that she is a half Aunt.
IAncestry will use the value to suggest various relationships from available data.
If you go to this site
https://dnapainter.com/tools/sharedcmv4
and put the total DNA you share with your half aunt in the top box, it will show the various relationships you could have with that value.
A half aunt would probably be between 492 and 1312. This amount could also be one of the relationships that you list. By coincidence, my great or grand nephew and I share 1100cMs so, without knowing the actual relationship, they could suggest that I am his half aunt, etc.
Gadget
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I have a similar case but further up a line where actually comparing a half great.with.a second cousin
Because although the great aunt only shares one great grandparent with me and the second cousin shares two
The great aunt s other parent is also connected to my family. Thru a different line .It would be interesting to know how strong your half aunts matches are to.your first cousins
Thank you for your interest and help,
As far as my results go, my half Aunt appears to be the only close family member who has had her DNA tested. I have tried to make contact, unfortunately she hasn’t responded.