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8

The adoptee is very likely your niece, specifically the half-sibling of the niece you have also tested. The relationship could be diagrammed as follows: The X-DNA is key to determining this relationship. A useful article to help understand X-DNA matches is X Chromosome Recombination's Impact on DNA Genealogy. You know that the adoptee is a nearly 100% half ...


7

One of my favorite math teachers in high school told us that whenever we got stumped, we should draw a picture to get a better definition of what the problem was. Here's a recent (12 June 2015) article by Louise Coakley, X-DNA's helpful inheritance patterns. Coakley published several graphs with the possible lines of descent marked out. Coakley says: ...


6

The GEDmatch Relationship Tree is a wonderful idea the imaginative people at GEDmatch put together. No, there is not much documentation about it and it is still said to be a "work in progress", but it has been there for a number of years and does something few if any other DNA analysis tools do. It uses the two people that you give it, whose relationship ...


6

The oldest answer has given a great overview of X inheritance, and I agree with what it says. It does take study to understand. Initially I suggest you mainly rely on Coakley's two main charts of X inheritance (one for a female descendant, one for a male descendant). The green boxes on those pedigrees show who could have carried the X segment you are ...


6

mtDNA and X-DNA mostly are not related. If two persons share the same mtDNA haplogroup it just means that their common direct maternal ancestor lived ~10000 years ago (when this haplogroup was developed). It means nothing more. Of course, this person may be your sister, for example, or maternal aunt/uncle. But you can prove or disprove it by comparing your ...


6

The tests can be trusted. You are not half-sisters. Paternal half-sisters, minimally speaking, share an entire X chromosome, as females inherit one X chromosome from their father. Beyond that, they share about 25% of their DNA all told. I recommend reading either of Blaine Bettinger's books on genetic genealogy. Your local library may have copies.


5

The lack of shared X-DNA segments is to be expected and does not imply you are unrelated. Men get their X chromosome from their mother and their Y chromosome from their father. If two men had the same father but unrelated mothers, they too would have closely matching Y chromosomes but no X-DNA match. There's more to the story, such as that men's single X ...


5

You inherit exactly half your DNA from each parent. So, no, you are not more related to one parent or the other. However, it is unlikely for you to inherit exactly a quarter of each of your grandparents' DNA. Often, you inherit 20% to 30% from each grandparent, totaling 100%. This is because you inherit a random 50% of each parent's DNA, so you may get a ...


5

The Chromosome Browser image you've displayed does show half matches, however, you should think of this display as a list of half matches, not a display with one half of a chromosome pair on top and the other half on the bottom. For instance, if you were comparing against five other people, and you and those five people all shared an identical segment, then ...


5

A possible explanation for these results is that you have more than one relationship – maybe you are half-siblings and also share a more distant relationship on your mother's side. For example, the man may be your half-brother because you share a father, and also be a second or third cousin via his mother. Just to diagram this possible scenario to give you ...


4

Based on the information provided I belive are only one of two scenarios are possible. You share a grandparent on your mothers maternal side. You are half brother's and sisters with the same mother; not your fathers side. You can reference the ISOGG Autosomal DNA Comparison Chart. But a more practical example of a similar situation is my grandfather. ...


4

I don't like calling it xDNA. I'd prefer to call it ChrX (chromosome X). So. The situation: [♂ G.Father ]==[♀ G.Mother ] XY XX [♀ Your mother ] [♀ Your aunt ] XX XX [♂ YOU ] [♂ Your cousin ] XY XY You share 100% of ChrX with your mother ...


4

The key to determining your relationship is your Total cM which is 1019.3 cM. If you are same generation level, then according to Blaine Bettinger's Shared cM Project, the only possible relation the two of you might have is first cousin. The Project's Table 1 Cluster Chart says that first cousins fall in Cluster #3 whose 99th percentile range is 486 cM to ...


4

For the record and for those interested, I want to give a little more detail than is in Leah's answer. Leah's answer is a very good overview and has the important points that a beginning genetic genealogist needs to know. The real world, as always, is a little more complicated. Our DNA is organized in three kinds: autosomal chromosomes (numbered 1-22) ...


3

Why do you believe that you're related to her through your father's mother? Why not through your father's father? Plotting the X inheritance path, your proposed relationship path means that you and your father should share some amount of X with this new second cousin. Because you don't, I do not believe that this is the appropriate connection. My reasoning:...


3

A match on maternal haplogroup may indicate a common ancestor on the direct maternal line (mother, mother's mother, mother's grandmother, etc). The inheritance pattern for the X chromosome is more complex. This article explains: https://dna-explained.com/2017/02/07/using-x-and-mitochondrial-dna-charts-by-charting-companion/ Keep in mind that in the 1800'...


3

Your wife got one X Chromosome from her mother and one from her father. Her half sister also got one from her mother and one from her father. Their fathers are different so those chromosomes won't have anything in common. Their mothers are the same, but the X Chromosome is taken from a combination of their mother's parents. It is about 150 cM long and will ...


3

No, you can't assume the match is on the paternal line. As a female, you have 2 Xs – one from each parent. As a male, your match has only one X – from his mother. X-chromosome inheritance is not linear. If you are related to his maternal great grandfather, for example, you will also not share any X-DNA. The following is a nice chart which highlights the ...


3

Females get one X chromosome from their mother and one from their father. Their father only has one X chromosome and it was passed whole to him from his mother. So two 1st cousin females who do share some part of their X chromosome can be related through their mothers or their fathers. But if they are related on their father's sides, then it must be ...


3

Based on the information you have provided, I don’t think you are quite on the right track. You state that: I believe that one of my female second cousin's uncle is my paternal grandfather. However, you could not inherit any X-DNA from your paternal grandfather. All of your X-DNA comes from your paternal grandmother and maternal grandparents. You ...


3

FTDNA will include segments as small as 1cM in X-matches; you'll need to compare in the chromosome browser to see how much you share with these paternal matches. If these matching segments on the X chromosome turn out to be very small segments, they're most likely Identical By Chance (IBC) and can be disregarded.


2

You said: "First, I have a 3rd cousin match from Ancestry who uploaded his info for me on gedmatch.com, and I see that he shares no X DNA with me. We're trying to figure out which of his great great grandparents we share" Your cousin is male. Males only get one X and it's from their mother. The simple way to think of this is that the X cannot be passed ...


2

You've indicated that both people are females. Females get two X chromosomes: one from their mother and one from their father. Males have one X chromosome, which they get from their mother. So that X chromosome segment could have come from your mother's sides or from your father's mother's side, but not on your father's father's side. That logic can ...


2

No, you need to carefully compare the X Chromosome overlap with the shared amount of other autosomal DNA. The catch is that X Chr is relatively small and men have only one X Chr and women - two X Chr. So it makes very difficult to interpret results correctly. Also as X Chr is investigated alone the provided results may prove very distant (and old!!!) ...


2

Your father got his one X from your grandmother. Your cousin's father also got his one X from your grandmother. The two fathers would on average match 50% since your grandmother's 2 X's recombine when passed to her sons and they each get random parts of those 2 X's. Since you and your cousin are both female, you would both get your fathers' complete ...


2

Without some additional information, no, you can't tell which of her parents you're related to based solely on the X-DNA match. You need to review your shared matches with her. Can you figure out how these people are related to her? Can you ask her how they're related to her? Once you know which parent those people are related to her through, you'll know ...


2

Congratulations on such a strong match. You and this woman are close family. She is not your grandmother. The cM total is out of range, the age difference is unlikely, and she would know if she had a child that was raised by someone other than her. She could easily be the full sibling of one of your father's parents. That's your great aunt. While many ...


2

There are many possible explanations. First, make sure these are really X matches. As others have suggested, look in the chromosome browser. The filter may or may not be accurate. Second, I agree with Leah: disregard segments that are too small. All segments are "real" but that's not the same thing as "meaningful." Anything less than 5 cM is almost ...


1

As previously indicated, the lack of matching X-DNA is not significant. A perfect y-DNA match implies a MRCA within 5-6 generations, a single mismatch implies a MRCA within 10-12 generations (roughly speaking). Once you get a match this close, you might want to upgrade to a higher-marker-count test to check further. However, the lack of other matching DNA ...


1

If you are at least half-sib you would still share TONS of DNA; no matter if they tested 23rd chromosome or not. I have a half-sister, and we share a lot and are inside "the range" listed on the 2017 chart done by Blaine Bettinger: https://isogg.org/wiki/Autosomal_DNA_statistics#/media/File:Shared_cM_version_3.jpg If you both share no DNA -at all-, she ...


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