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General => Ancestral Family Tree DNA Testing => Topic started by: Ruskie on Thursday 20 December 18 05:45 GMT (UK)
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Yesterday I received my father's FTDNA Autosmal results. Both my results and my father's results show a match with "LB".
Estimated relationship with LB is 2nd to fourth cousin.
My father has 89 shared centimorgans with the longest block 39.
Mine is 86 and 36.
I have an X match but my father does not. What does this say about where LB might connect with both of us?
Over a year ago I contacted the "match" whose account is managed by a second cousin once removed. The contact claims I do not match LB on her maternal grandmother's side with "either of her cousins" :-\ so any match must be on LB's father's or paternal grandfather's side. Frustratingly, the contact has no knowledge of that side of the family so can't help me.
I am looking for clues as this is my father's best result. I have read a bit about X matches but I am still confused.
Thanks for any help.
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Hi Ruskie,
Try asking on:
UK Genealogy Help, - It's a Facebook (Closed) Group. You have to email them asking to join.
They are very helpful in explaining issues such as you are looking at.
Romilly.
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Thanks Romilly but I am not on Facebook. :)
I sent another email to LB's contact and they were a little more helpful this time - gave me a few more names (none of which tally with names in my tree). They are going to try to put me in contact with LB's son, so there is glimmer of hope there.
I am still curious about the meaning of this X match. :-\
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I also find this book very helpful:
'The Family Tree Guide to DNA Testing and Genetic Genealogy' by Blaine T Bettinger.
Romilly.
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Thanks again Romilly. I have read a few online articles by Blaine Bettinger. As I said, there is lots online about X matches, but after wading through several, I am even more confused than ever.
Some say X matches mean the connection is through the maternal line. If that is the case why do I have one and my father does not? :-\
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Thanks again Romilly. I have read a few online articles by Blaine Bettinger. As I said, there is lots online about X matches, but after wading through several, I am even more confused than ever.
Some say X matches mean the connection is through the maternal line. If that is the case why do I have one and my father does not? :-\
There are lots of charts in the book which help to explain these sorts of issues...
I've also found the GEDMatch Site very helpful. Have you uploaded your DNA results to that Site?
Romilly.
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Here is Blaine's website in case you are interested.
https://thegeneticgenealogist.com/
:)
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Hi Ruskie,
Do you know the sex of the match LB? Have you had your mother tested for autosomal DNA?
pughcd :)
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Romilly, yes I have uploaded both mine and my father's results to Gedmatch (his only yesterday as I have only just received his autosomal results).
Thanks for the link to the website uk4753. As I said, I have read a few of Blaine's articles, but still confused.
pughcd, my mother is deceased but no, I have not tested her DNA. This match with LB is definitely through my father's ancestry. LB is a female. :)
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Hi Ruskie,
I (male) and my half-sister have both transferred our autosomal DNA raw data to FamilyTree DNA.
I have an X-match with my half-sister. My half-sister has an X-match with me. We share the same mother. I do not have any other X-matches on the first three pages of matches. Thus I match just 1 person on the X-chromosome but have 89 negative matches.
On the other hand, my half-sister has 66 X-matches in her first three pages of cousin matches, including me. She has just 24 negative X-matches. Her top matches, excluding me, are a paternal line that I do not share.
There is one female individual on the first page of matches who my half-sister has an X-match with but I do NOT have an X-match with. My half-sister shares 59cM, longest block 16cM and I share 55cM, longest block 16cM with this female individual. Her family tree indicates that she has geographical origins similar to our mother. This sounds similar to your situation.
I would recommend you ask the DNA provider for their explanation. FamilyTree DNA are very proactive, if that's who you tested with.
Excellent question!
pughcd
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Thanks pughcd. Yes, your X match situation does sound similar to mine, though I don't know if there would be a difference with a half sister as opposed to a father? :-\
Apparently females tend to get more X matches than males which may explain your lack of X matches?
This looks like it should be useful and explains things well but I find it quite complex:
http://www.genie1.com.au/blog/63-x-dna
This says that it is difficult to work out where the X match comes from. I don't know if my situation is simply explained by the fact that females get more X matches than males, which is why my father "missed out"? :-\
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Ruskie, any DNA you have including any on the X chromosome has to have come from one of your parents. If your father does not have an X Chr match with LB he can't have passed that segment on to you.
Having stated the obvious, there is a problem with X matches in that they aren't terribly reliable. Anything less than 20cM's is likely to be false.
There has been a study in which several trios of daughter/mother/father matches were examined and it was found in all cases that an X match under 20cM's with the daughter did not have a corresponding match with either parent.
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Hi Spike. Thanks for that.
I am 100% sure that my connection with LB has come from my father, but I understand that X matches are not reliable. He could not have passed it to me without it showing in his own matches? :-\
LB and myself share 15.22cM on the X match, so under the 20cM in the test you mention.
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Thanks Ruskie,
The article by Louise Coakley, 2015 is excellent. I have just downloaded the pdf.
pughcd :)