Need help with xmatch for 1st cousin great aunt. I can find no common Ancestors where do I go now

+4 votes
829 views
On My Heritage it states that myself and Chris are 1st cousins great Aunt. on gedmatch we are related within 2 generations. We both have extensive trees but can find no common ancestor. Gedmatch also shows an x match so its not like there are lots of places to look. We are exploring all sorts of scenarios and still have no real clues. Is there a kind dna expert out there that can point us in the right direction please. I am contacting other matches to us both but have had no success with that yet.
WikiTree profile: Janet Mackenzie
in Genealogy Help by Janet Mackenzie G2G Crew (460 points)

3 Answers

+5 votes
My Heritage not a good source,most info off Family Trees

Give me names date birth where lived who married.
by Wayne Morgan G2G Astronaut (1.0m points)
Thanks Wayne

My grandparents Leonard alfred hood 1904 Canterbury m May Louisa Wills 1910 canterbury

Paternal grandparents Alfred Greer Webb (Changed to hood c1900)1877 manchester m Alice Victoria Wooley 1886 Shropshire

George w wills 1875 battersea m Dorothy E E Church 1887 Peckham

Maternal  g/p Frederick Mark Fuller 1907 Hailsham m Nelly B Saunders Hailsham 1906

Walter Fuller 1872 Hailsham m Ruth Boniface Hailsham 1874

Francis J Saunders 1881 Hailsham m Lillian E Woods

Christine's g/PJohn Huggett 1885 haggerston m Mary Hurley 1887 Bethnal Green

John Huggett 1857 Shoreditch m Mary Ann Crouch 1885 haggerston

Robert Hurley 1855 Bethnal Green m Ann Maulkerston 1855 Bethnal green.

Arthur Vincent 1865 islington m Amelia Pilbeam 1864 Walsall

John Vincent 1843 Somerset m Harriet Welsh 1846 Somerset

Henry Pilbeam 1824 Hackney m Matilda Bliss 1828 Gloucester

That's the basics we do have more detail if you need it

Thanks for your help
Just send me 1 person with date birth Town and country

and who he married.Then i will ask for another.
Leonard Alfred Hood 02/09/1904 Canterbury m May Louisa Wills
+6 votes

If you mean that you match on the x chromosome, then the specific pattern of x chromosome transmission means you can knock some of the people on the list given to Wayne off your list. (If not then ignore)

A man receives his one X chromosome from his mother. A woman receives an X chromosome from each parent.

 George Hood received his X chromosome from his mother Mary Willis. Leonard his father gave George  his Y chromosome  so can be excluded .

Shirley Fuller received an X from each of her grandparents (Frederick Fuller and Nellie Sanders). 

See https://www.wikitree.com/treewidget/Hood-4730/89

Here  are your relations (on wikitree)  who could have shared DNA from the x  chromosome https://www.wikitree.com/treewidget/Hood-4730/89#X 

The chart gives  predicted percentages of DNA shared for each generation .However these percentages may be missleading as descibed here. https://www.google.com/amp/s/dna-explained.com/2014/01/23/that-unruly-x-chromosome-that-is/amp/

Your match with Chris may have originated from a more distant common ancestor than that  predicted by the percentage shared.

I'd start by filling in an X dna charts https://thegeneticgenealogist.com/2008/12/21/unlocking-the-genealogical-secrets-of-the-x-chromosome/ for each of you.

Are there any gaps? Is each generation really  accurate i.e have you got firm  evidence for each generation?  (Baptisms or birth registrations , marriages etc  at the momenr, your wikitree profiles lack this) 

by Helen Ford G2G6 Pilot (459k points)
edited by Helen Ford
I have a xmatch chart for myself. I will do Chris,s next.

We both believe our charts to be accurate. But as we all know mistakes can and do happen

I'm aware I need to put sources on here. I should of done it as I went and now it feels a very big job. I do have sources for each entry.

Thank you for your help though
+6 votes
Hi, Janet!

Sounds like you've uncovered a family secret, to me!

The first thing I'd do is compare your ages. It's not fool-proof, but it can give a "first guess" at how many generations apart you are (if any).

By "1st cousin great aunt", I presume you mean you match at the level you normally see for a 1st cousin, or a great-aunt. That covers the options for when you are zero or two generations apart. The other possibilities are half-aunt (which should be considered carefully, in the case of a "mystery relative" like this one), if you're one generation apart, or great-grandmother (which we can probably rule out immediately), if you're four generations apart.

Exactly how many cM are we talking about for this match, by the way? If it's really low for that level, it might really be in the NEXT level down (a child of a 1st cousin, for example).

But to REALLY figure this out, you need to both do some DNA confirmation. There's a formal procedure for that here (which I recommend doing), but for the moment just hunt within your better matches for people that you can tell are relatives on various sides of your family. For this puzzle, you probably only need to find matches who are descended from each pair of your great-grandparents - in other words, your 2nd cousins, give or take a generation.

If you don't happen to have any 2nd cousin matches on a given side, then you need to go back a generation, and look for 3rd cousins.

HOWEVER, given that there is a mystery relative, it sounds like ONE of you should NOT be able to find matches to part of your tree, because that part corresponds to an ancestor who is NOT a biological ancestor!

Further, you should see which matches you have IN COMMON. If you can find out how you (or your match) is related to THOSE matches, that tells you what part of the tree has the issue.

Let us know how it goes! Good luck!
by Living Stanley G2G6 Mach 8 (89.4k points)
Been thinking about your comment that my maternal grandfather is Chris father. Not possible he died 1940 she born 1949
It works like this:

Chris' father was b 1908, and was still living through at least about 1949 (when Chris was born). He would be your biological grandfather, not Mr Fuller, who d in 1940.

So your mom is Chris' biological half-sister, both having the same biological father (Chris's father). They both got his X Chromosome, 100% intact - all 196cM of it.

With your mom being a woman, she had two X chromosomes, and therefore there was recombination, and your X chromosome from HER is roughly 50% from each of your maternal grandparents. In your case, that meant 85.6cM from your biological maternal grandfather (who ls also Chris' dad).

So the X match actually IS helping out!

Your mom's brother doesn't match Chris because he's only a half-brother to your mom - they have different biological fathers. You match Chris through your mom's biological father, but that isn't your uncle's biological father, so he doesn't match her.  Maybe your uncle's father is Mr Fuller, or maybe he's yet another guy - you'd have to see whose relatives show up in his matches.

Sounds like we're "on the same page" about you vs Chris on GEDmatch and X-DNA matching.
Wow I never even thought along those lines. I will dig a bit deeper with that. There were several other siblings.

Is there a way of proving this theory?
Maybe a better question is: "Is it ALREADY proven?" I hate to even "go there", because this stuff can be so tricky. Just when you think there's no other possible way the pieces can fit together, something else shows up to throw you in another direction.

Before we get into that, I should say I finally read through that X-DNA article thoroughly.  What I got out of it is that the cM of the X-DNA match means nothing - it can be all over the map for even one generation. What the match, itself, tells you though is that your common ancestor has to be one that you possibly get X-DNA from, and the same for the person you match. In your case, for example, it proves that your paternal grandfather is one of your ancestors who CAN'T be a common ancestor. This is what Helen as talking about, in another answer.

So what do we know so far, within reasonable doubt?

* Chris is a 1C-level relation, with an X-DNA match, no matching ancestors

* Your maternal uncle is ALSO a 1C-level relation, NOT a biological uncle

* A 1C-level relation can be a 1st cousin, half-aunt/niece, great-aunt/niece, or great-grandmother/daughter

* Chris and your maternal uncle are NOT related

* Chris was b 1949, her father b 1908, while you were born 10 yrs after Chris; your grandparents were born in <1904, <1910, 1907, and 1906; your maternal grandfather died in 1940.

We can deduce:

* We can throw away the gt-grandmother possibility right away, obviously, since you're only 10 years apart in age.

* Your youngest gt-grandmother was born in 1887, 62 years before Chris was born, so Chris can't be a gt-aunt of yours either. I'm just going to go ahead and assume you're too young to be one of her gt-aunts, too - I'm just including this unlikely case for completeness.

* So that leaves 1st cousin (1C) and half-aunt/niece as the only possibilities. If she's a half-aunt, the common ancestor is one of your grandparents. If she's a 1C, you share a pair of grandparents. To be a half-niece, you'd have to have a half sibling at least about 25 years older than you, so we can rule that out.

* Summarizing so far, EITHER

(1) one of your biological grandparents is one of Chris' parents. We can exclude your biological paternal grandfather (whether he's your "on paper" paternal grandfather or not) because of the X-DNA match. We can also exclude your "on paper" maternal grandfather, who was deceased when she was born, but your biological maternal grandfather could be somebody else (that's actually our best theory).

OR

(2) your paternal grandparents are also her grandparents - it can't be your maternal grandparents, because Chis doesn't match your maternal (half-)uncle.

SO... to answer my own question, no I guess we're not "proven" yet, but we've narrowed it down to a very small number of possibilities, and it should be fairly easy to narrow it down still further:

(A) For Chris to be a 1C, your father would have to have a sibling who had a child that you didn't know about. To eliminate this possibility, we just need Chris to tell us that she definitely has DNA matches to reasonably close relatives (say, 3rd cousin or closer) on both her father's and her mother's side. That would prove that her parents are really her biological parents - and that she CAN'T be your 1st cousin. Hopefully, that's an easy one

(B) With the 1C possibility eliminated, it's a matter of identifying which of your three possible biological grandparents are a parent of Chris'. The procedure is basically the same. If you can identify a DNA match with a 2nd or 3rd cousin who's related to you through your paternal grandmother, then that grandmother is confirmed (and should NOT match Chris), and you can eliminate that possibility. Do the same with your maternal grandmother, too.

(C) If you can do all that, then the theory is already proved, but for good measure try to also show that you both have matches to relatives of Chris' dad.

(D) We're assuming that your maternal uncle at least has the same mother as your mom, since the family doesn't seem to be aware that he's anything but a full brother to her. So they LIKELY had different fathers (rather than different mothers). Technically, that could be true without your maternal grandfather not being your biological one, so it can't really PROVE anything, but it's a strong "hint" as to what is likely going on.
Thank you  Frank for that comprehensive answe. When I return home I will digest and ask Chris the relevant answers.

I know chris.s son robin has done a test on my heritage. And I am waiting for my brothers to come back on Ftdna I will upload to my heritage and gedmatch for consistency. Will that help our quest?

Once again thank you for your help
Right I think I have all of that. We will start looking again.

My dad did father a girl in 1952/4 who was adopted. So wrong date to be Chris. He told me about it so I know there are no others.
I now have some responses from Chris to your questions.

She has no close matches or anyone other than her son that has tested. Her closest match apart from us is Christopher B. Who is 1c 2r. 3c1r.

They have 99.4 shared CMS the longest 29.1

The only person she has ever confirmed as matching is John V 4th cousin

Her parents lost contact with siblings and she has no knowledge of them

She knows her mum is biological as she was an only child and her mum had c section scar.

Onwards with my part
I realize you ladies are in the UK (at least you seem to be, I don't really know about Chris),so matches might be a lot harder to come by. In case I'm not being clear though, for Chris - my Part (A) bit, I'm not just talking about on GEDmatch - any match at all (whether on MyHeritage, or wherever), to any relative who's entirely on her father's side or her mother's side will do. It sounds like you get that, but I just want to be sure (kind of out of desperation!).

* Chris' son's DNA can tell him about his father's side, but shouldn't be able to help prove our theory beyond what his mother's already tells us.

* You only have half your parents' DNA, but between the two of you (meaning you and your brother) you should have about 3/4, so his might help some.

* I used the tool on GEDmatch that tells you which people you and Chris BOTH match , and it was a super long list. I compared it to Chris' "one-to-many" list, and among her top 30 or 40 matches, you share roughly half of them. That seems consistent with the idea that one of her parents is one of your ancestors. I didn't look as closely at your list, but it certainly doesn't seem like 1/2. Still, it might be roughly 1/4 - about what you'd expect if Chris' parent were one of your biological grandparents.

* Which side is "John V" on? At the 4C level, you should really have a couple of matches for a proper confirmation, but I guess it's better than nothing.

* 99.4cM should be a 2C1R or 3C - it shouldn't be too hard to figure out how he's related, if he gives you a least a little to go on. I take it you're not a match to him? Or is he on a different platform?

* Ronald C is a decent match to both of you on GEDmatch, so I hope you're trying to contact him. He ought to be about a 3rd cousin to you, so it shouldn't be too hard to figure out, if he'll talk. The whole idea of getting on GEDmatch is to talk, so the odds of getting an answer should be best there, but sometimes even THEY don't answer.

* I suppose even a closer relative than 2C could help for your end - "Part (B)". We've already seen that with your uncle appearing to be a half-uncle. If you had a 1st cousin, who only had the cMs for a half-1C, for example. Or if you have a 1C on your dad's side, who has cMs showing they're a full 1C (not a half-1C) - that would show that both your paternal grandparents are your biological grandparents.
Hi Frank yes I get that first part.

John V is on her paternal line. He is not showing up on my heritage. I will ask the question though.

R Coe is managed by another Coe and they have no name matches to either of our trees. His heritage is 96% Ashkenazi and all names are jewish of which we don't share?

None of my cousins have any interest in family history. I will ask if they would consider taking a test. I find people very guarded about DNA?

Yes you are correct we are both from the UK. And we have access to gedmatch and I use the chromosome tools on my heritage. But the relationship side baffles me.  And how many shared chromosomes make what relative??

I have been researching my tree for several decades on and off. But only recently done my DNA. So it's very much a learning experience. I've tried reading different material but I haven't found anything that speaks in layman's terms.  This experience has been invaluable and  I  really appreciate the time and trouble you have gone to to help me understand it.
So we don't really have solid DNA evidence that Chris' parents are her biological parents, but with the 4C on her father's side, and proof that her mum at least had a child (realistically, if it wasn't Chris, then she'd probably have heard about that), it seems safe to at least tentatively rule out (B). The right matches will show up eventually. It's funny how you're her closest relative!

These things are like jigsaw puzzles. The first pieces are hard to put together, but the more you get, the easier the rest becomes.

There's only about a 45% chance of getting a DNA match to a 4C, so if John V doesn't match you, it doesn't mean anything. A 2C1R is virtually 100% guaranteed to have at least a weak match, and a 3C is about 90%.

With Coe being such a solid match to you both, along with some of what we're seeing with other matches, it's a safe bet that your newly-discovered biological grandfather is at least partly Ashkenazi.

One of the big "curve balls" in this DNA stuff is endogamous populations - where a relatively small population has been isolated for a great many generations. The cM values are inflated, and the Ashkenazi are the quintessential endogamous population. So Coe is undoubtedly a relation, but perhaps more distant than what I would normally expect.

The question of cM vs Relation Level really doesn't have a very precise answer. I found various sources, and they all differ from each other somewhat. An additional complication is that every company calculates it a bit differently, so the numbers come out a bit different, but they lump all of them together. Blaine's chart seems to be ubiquitous, but I find it to grossly overstate the average values and the maximum values (it admits to having certain inherent flaws as to where the data comes from). I collected by own data due to the frustration with inadequate data. Up through 1C1R is from GEDmatch data; 2C and up is for AncestryDNA (which is usually a bit lower than the others):

(A) over 3150; parent/child

(B) 2250-3150; full sibling

(C) 1400-2250; niece/nephew/aunt/uncle, half-sibling, grandparent/grandchild

(D) 500-1200; 1C, half-niece/nephew/aunt/uncle, great-niece/nephew/aunt/uncle, gt-grandparent/gt-grandchild

(E) 210-620; 1C1R, half-1C, half-gt-niece/nephew/aunt/uncle, gt-gt niece/nephew/aunt/uncle

(F) 10-400; 2C, half-1C1R, 1C2R

(G) thru 250; 2C1R, half-2C, half-1C2R

(H) thru 140; 3C, half-2C1R, 2C2R

(I) thru 85; 3C1R, half-3C, half-2C2R

(J) thru 75; 4C, half-3C1R, 3C2R

(K) thru 65; 4C1R, half-4C, half-3C2R

(L) thru 55; 5C, half-4C1R, 4C2R

Really, once you get below about 50cM-60cM, it can normally be anything from 2C1R to 6C1R.

At least that's what I'm seeing. Sometimes you see bigger numbers due to intermarrying/endogamy, or when mostly-male lines are involved.

You're very welcome! Let me know if you find out more - I always want to see how my numbers match up with what others are seeing, and to generally put these theories to the test!

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