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JFWinstone
03-15-2017, 06:57 PM
I put this as a comment on another thread but I thought I would ask on here instead so that it didn't get lost. On Dr Mcdonalds BGA for my mother's data my mother's X chromosomes one is almost entirely East Asian which I'm sure came from her father so does that mean my grandfather's maternal line was likely East Asian origin? Or am I getting the wrong idea here? Unfortunately I don't know any of his family to get them tested and he passed away over a decade ago.

Bollox79
04-02-2017, 08:50 PM
For X-chromosome haplogroup stuff - I am T2b2b - and it appears via the geographical data per FTDNA that it's most common in Ireland. That lines up with my paper well as my maternal line is from Western Ireland - probably SW or Roscommon. Second most common (about half the kits) in England and Scotland and Wales etc. Don't know if that helps... what does FTDNA say about geographical matches for your haplogroup?

geebee
04-04-2017, 06:56 AM
I think you're a bit confused. You speak of "X-chromosome haplogroup stuff", but your T2b2b refers to your mitochondrial haplogroup, which has nothing to do with your X chromosome.

Rather than go into the distinction here, you might take a look at the following articles:

https://en.wikipedia.org/wiki/X_chromosome

https://en.wikipedia.org/wiki/Mitochondrial_DNA

geebee
04-04-2017, 07:09 AM
I put this as a comment on another thread but I thought I would ask on here instead so that it didn't get lost. On Dr Mcdonalds BGA for my mother's data my mother's X chromosomes one is almost entirely East Asian which I'm sure came from her father so does that mean my grandfather's maternal line was likely East Asian origin? Or am I getting the wrong idea here? Unfortunately I don't know any of his family to get them tested and he passed away over a decade ago.

Generally, a woman's X chromosomes will not be phased -- just like her autosomes. She has two copies, and it usually isn't possible to distinguish them in the data file. Because you only have one X chromosome, yours will essentially be automatically phased. By "phased", I mean where the results are reported as individual SNPs on each copy of each pair of autosomes and X chromosomes, rather than reported as pairs.

However, it's entirely possible that your mother's paternal grandmother was East Asian. If she was, I'd expect East Asian to show on at least some of the autosomes, too. But the X chromosome would be different because it would not have been recombined between the time that your father's mother passed it on to him, and the time he passed on a copy to your mother.

It looks to me as if the test results you're showing may very well support the possibility of an Asian great grandparent. The amount of DNA you'd expect to inherit, on average, would be about 12.5%.

JFWinstone
04-04-2017, 01:11 PM
Thank you for your response. I'm attaching my mother's chromosome painting from Dr Mcdonald to this thread 14889. My mum gets East Asian in her results about 22%-30% between the different companies.

geebee
04-04-2017, 02:24 PM
Thank you for your response. I'm attaching my mother's chromosome painting from Dr Mcdonald to this thread 14889. My mum gets East Asian in her results about 22%-30% between the different companies.

Yes, that seems about what you'd expect if one of her grandparents is East Asian. Since one of her X chromosomes seems to show recent recombination between Europe and the Middle East, I'd guess that one is from your mother's mother. The one that doesn't show recent recombination is probably from your mother's father. Therefore, I'd say your mother's Asian grandparent was likely her paternal grandmother -- or your maternal grandfather's mother.

The X chromosome is fascinating to me, because of the way it's passed on. When passed on by a father, it it is simply a copy of whatever he inherited from his mother. When passed on by a mother, it may be a recombination of the two X chromosomes she received from her parents -- but she can also pass on a copy of either X, without recombination.

Among my siblings, this is what happened to one two of us. My first brother and first sister appear to have a copy of the X chromosome our mother inherited from her father, with no DNA from our grandmother. The rest of us inherited maternal X chromosomes that include DNA from both maternal grandparents, although mine is mainly from my maternal grandfather. The only part from my grandmother is about 30 cM surrounding the centromere.

This is handy when trying to determine how I'm related to people who happen to match me on the X. Unless we match close to the centromere, I can look to my mother's paternal grandmother. Unfortunately, that has also convinced me that she wasn't the woman she was always said to have been. But that's a story for another time.

JFWinstone
04-04-2017, 02:57 PM
My mum is mixed race from very different ethnicities so it is very easy to tell the two X apart as my mother is half british and half mauritian. Her mum was South West English and her father was Mauritian

geebee
04-04-2017, 06:11 PM
I'm afraid I don't know much about Mauritius; except I did know that it's in Indian Ocean, over a thousand miles off the southeast coast of Africa.

When I looked it up, I was slightly puzzled because the article I looked at mentioned that it has an ethnically mixed population -- which didn't surprise me -- but mostly African and Indian. I remembered you mention that your mother was showing a lot of East Asian, not South Asian.

But I did a bit of a Google search, and found this: https://en.wikipedia.org/wiki/Mauritians_of_Chinese_origin

Is it possible your mother's father's mother came from this group?

EDIT: Would an admin please delete this post (it's duplicated by the following one, but I added an edit to that one that I'd like to keep). I tried to delete it myself, but I couldn't see where to do that.

geebee
04-04-2017, 06:14 PM
I'm afraid I don't know much about Mauritius; except I did know that it's in Indian Ocean, over a thousand miles off the southeast coast of Africa.

When I looked it up, I was slightly puzzled because the article I looked at mentioned that it has an ethnically mixed population -- which didn't surprise me -- but mostly African and Indian. I remembered you mention that your mother was showing a lot of East Asian, not South Asian.

But I did a bit of a Google search, and found this: https://en.wikipedia.org/wiki/Mauritians_of_Chinese_origin

Is it possible your mother's father's mother came from this group?

(There do also appear to be a number of both South Asian segments, and African in the painting. Seems to fit very nicely with what you've said.)

JFWinstone
04-05-2017, 02:15 AM
Mauritian genetics are rather diverse because of slavery and indentured labour plus there wasn't any indigenous people there. The main areas that they came from were Madagascar, Mozambique, India and various areas of East Asia. Trying to unravel it has been rather interesting.

Her Wegene breakdown was interesting (aside from the European which was just bonkers).

Chinese 19.76%
Naxi/Yi 8.57%
Southern Han Chinese 5.22%
Gaoshan 4.33%
Dai 1.28%
She 0.33%

Southeast Asian 2.3%
Cambodian 2.29%

Northeast Asian 1.26%
Japanese 1.14%
Yakut 0.11%

South Asian 6.52%
Sindhi 3.63%
Bengali 2.71%
Indian 0.17%

African 16.56%
Yoruba 12.52%
BantuSA 3.29%
Mbuti 0.74%

Oceanian 1.53%
Papuan 1.53%

DNA.Land

West Eurasian 60%
Northwest European 43%
Finnish 7.9%
Gujarati 3.9%
Dravidian 1.3%
Kalash 1.9%
Southwestern European 1.3%
South European 1.1%

East Asian 22%
Central Chinese 7.6%
Japanese/Korean 3.9%
Southeast Asian 4.3%
Cambodian/Thai 3.8%
Taiwanese 2.4%

African 14%
Lower Niger Valley 5.4%
Senegal River Valley 2.1%
East African 6.8%

Native Oceanian 2%

JFWinstone
04-05-2017, 02:25 AM
DNA Tribes:

Table 1: Your Continental Core Mixture
Continental Core Mixture
European 49.1%
Sub-Saharan African 19.1%
Asian 17.2%
South Asian 9.2%
Siberian 2.9%
Pacific 2%
Amerindian 0.4%
North African and Middle Eastern 0.2%

Table 2: Your Regional Cluster Mixture
Regional Cluster Mixture
Northwest European 42.1%
South Chinese 11.1%
Madagascar 9.4%
Gangetic 8.4%
West African 5.4%
Finnish 4.8%
Nilotic 4.1%
Yeniseian 2.5%
Basque 1.9%
Melanesian 1.8%
Khoisan 1.6%
Japanese 1.5%
Tibetan 1.4%
Tajik Pashtun 1.2%
Africa Great Lakes 1.2%
Other 1.6%

Dibran
05-15-2017, 01:13 AM
How can one check this for their x or y chromosome? Do you have to email this Mr McDonald fellow?

Jesse1961
08-30-2017, 12:50 PM
So there is a chromosome painting of our X-DNA if we only ask the right guy. I've been asking this X-DNA chromosome painting at Gedmatch for quite a while now, but i got no answers.

How can we avail of Mr McDonald's expertise?

Edward J
09-01-2017, 05:00 PM
23andme shows admixture on X chromosome.

Mine would be Italian, but shows up as 100% Northwestern European. Not sure if there is really anything to read into with that though.

Nnobrega
07-17-2018, 08:12 PM
Im Portuguese and my X chromosome is damn near 100% French/German. That is expressed almost nonexistently in my phenotype. What does this X chromosome say about my future son/daughter?

geebee
07-18-2018, 06:23 PM
One of the things any good ancestry analysis depends upon is phasing of the DNA results. This requires having a tested and linked parent. It's possible to do an analysis without phasing, but I believe the results are less reliable.

In the case of the X chromosome, it's essentially phased even without a tested parent ... but only for males, since they only have one X chromosome.

Yet even when there is a linked parent, there can still be some anomalies. I tested at 23andMe, as did my father and all five of my siblings. He's linked to all six of us, and our results are still only mostly consistent.

For example, my three sisters should show exactly the same ancestry for their paternal X chromosomes -- since our father, having only one X, could only pass an identical copy on to each one. This is not the case. While on a regional scale all four show "broadly Southern European" across the entire chromosome, differences appear at the country scale.

24724

You can see from the attached picture file that my father shows quite a bit of "Italian" on his X chromosome, but none of my sisters does. At the same time, two of my sisters show "Balkan" while my father does not. The remaining sister shows neither Italian nor Balkan. And keep in mind, this is with respect to their paternal X chromosome, which should exactly match his only X.

On our maternal copies, it would be more expected that we would show some variation. Recombination is possible here, since our mother had two copies -- one from each of our maternal grandparents.

Two siblings, however -- my brother Bernie and my sister Kim -- actually received identical copies. Further, all of the DNA on the maternal X of each of these two siblings came from just one grandparent: one maternal grandfather. My X chromosome also matches each of these two siblings, except for an approximately 20 cM region surrounding the centromere.

My other brother, Curt, has three regions where he doesn't match Bernie. One of these includes the region I inherited from my grandmother, plus a significant amount of DNA on each side. He has an additional region that also came from our grandmother.

My youngest sister CJ, however, is the one who inherited the largest share of the X chromosome our grandmother passed on to our mother. Interestingly, she is also the only one of us whose maternal X chromosome shows anything other than "British & Irish". In fact, her X chromosome doesn't show any "British & Irish", even though she does have some matching with each of the rest of us.

Instead, her X chromsome shows Scandinavian -- in a region where she mostly doesn't match my brother Bernie, my sister Kim, or me. However, there is at least a bit of overlap with me, and yet I don't show any Scandinavian here. CJ also shows a segment labeled as "Native American" on her X chromosome. But this is in a region in which she doesn't match any of her siblings, and we do have a small amount of Native American ancestry from both maternal grandparents.

The point is, for a variety of reasons the ancestry calculations are not perfect. This is clearly the case when family members who ought to match in certain ways (based on where they share DNA), fail to do so. Generally it isn't anything as significant as one having "broadly Southern European" where the other has "broadly Northern European", but more like "Balkan" instead of "Italian"; or only the more general category for one family member and the more specific category for another.


Here's what our Ancestry Composition looks like on the maternal X chromosome.

24725

Again, keep in mind that for most of CJ's "Scandinavian" and all of her "Native American" on her maternal X chromosome, she really doesn't share the same DNA as the rest of us. But there is some overlap with me in the region labeled as "Scandinavian", even though it doesn't show as Scandinavian for me.

EDIT

I should note that for any X chromosome DNA from our maternal grandfather, "British & Irish" may actually be reasonable. His X chromosome came from his mother, who was born a Muncy. Some sources list Muncy as an English name, a variant spelling of Munsey.

It's a more complicated picture for DNA from our maternal grandmother's X chromosome. Both of her parents were half Menorcan, but her father had an Alsatian mother. Therefore, the X chromosome our grandmother inherited from her father should be traceable back to Alsace-Lorraine.

The 20 cM I inherited, however, definitely came from my grandmother's mother. I know this because I share the entire region with some half 2nd cousins on that side. They're descended from my great grandmother, but not my great grandfather.

It, too, might be British & Irish. My great grandmother's mother was born with an Irish surname -- Ryan -- although she actually came from a variety of ancestries. These included, in addition to Irish: Swiss, French, and Native American.

It's actually possible that the segment I inherited has a "British & Irish" origin, while my sister CJ inherited a different segment with a "Native American" origin. But, in the overlap region that is "Scandinavian" for my sister but "British & Irish" for me, it can't be both at the same time.

JoeyP37
07-22-2018, 01:35 AM
My X-Chromosome is primarily British and Irish, which makes sense since my mother is 87% British and Irish. But there is a snip of Native American on there, and she is at most .5% Native American. So my X chromosome is 95% British and Irish, and 5% Native American. My Virginia-born great-grandfather is said to have some native blood, so that's where it's from.

JerryS.
07-22-2018, 02:22 AM
neophyte here so have patience.....

(I'm a male)

my X: (mom) paternal X is North German, maternal X is English and Scottish.

my Y: (dad) paternal Y is English and Scottish, maternal X is English and South Italian.

since my X is fairly North Sea regional, and the Italian is from my dad's X, and I inherit only Y from my dad, how do I get the Italian DNA showing with the population models and so forth? is it the Italian X recombining with his English Y or just sort of rubbing off on it?

JerryS.
07-22-2018, 02:28 AM
How can one check this for their x or y chromosome? Do you have to email this Mr McDonald fellow?


So there is a chromosome painting of our X-DNA if we only ask the right guy. I've been asking this X-DNA chromosome painting at Gedmatch for quite a while now, but i got no answers.

How can we avail of Mr McDonald's expertise?

I've yet to be able to get an answer for this from anyone, but plenty of excuses reasons.... like he's busy, he doesn't do this anymore.... but no one in the know that says this.

msmarjoribanks
07-22-2018, 03:10 AM
neophyte here so have patience.....

(I'm a male)

my X: (mom) paternal X is North German, maternal X is English and Scottish.

my Y: (dad) paternal Y is English and Scottish, maternal X is English and South Italian.

since my X is fairly North Sea regional, and the Italian is from my dad's X, and I inherit only Y from my dad, how do I get the Italian DNA showing with the population models and so forth? is it the Italian X recombining with his English Y or just sort of rubbing off on it?

You inherit one copy of chr 1-22 from your mom and another from your dad (although it's not separated out unless you phase it). Most of your autosomal is from those, and that's what the ancestry estimates are based on. X and Y (chr 23) are the only ones that are different. And then mtDNA is a separate thing.

firemonkey
07-22-2018, 11:18 AM
My X chromosome on 23andMe is French and German. My mother's known ancestry- Scottish,Irish and maybe a very small of English.

JerryS.
07-22-2018, 08:07 PM
My X chromosome on 23andMe is French and German. My mother's known ancestry- Scottish,Irish and maybe a very small of English.

while close via the compass, that's not at all an acceptable differential. how do they mix up those two groups (Gaelic/Celtic and Gaul/Anglo-Saxon)?

msmarjoribanks
07-22-2018, 08:20 PM
23andme shows admixture on X chromosome.

Mine would be Italian, but shows up as 100% Northwestern European. Not sure if there is really anything to read into with that though.

23andMe is the only X chromosome ancestry source I have.

One of mine is British Isles (good bet that's from my dad, since his mother's ancestry is almost all early colonial American from the British Isles) and the other is about a third British Isles and a third unidentified NW Europe (any part from my mom's dad would have been all Swedish, in fact, since his mother was 100% Swedish, and my mom's mom's part would have been a mix of English/Scots/Irish/German).

msmarjoribanks
07-22-2018, 08:23 PM
My X chromosome on 23andMe is French and German. My mother's known ancestry- Scottish,Irish and maybe a very small of English.

Out of curiosity, what percent French and German do you get overall?

firemonkey
07-22-2018, 10:56 PM
Out of curiosity, what percent French and German do you get overall?

13.7% . I get one dot for Netherlands.

Teutorigos
09-02-2018, 01:50 AM
My X chromosome on 23andMe is French and German. My mother's known ancestry- Scottish,Irish and maybe a very small of English.

Southern England has French and German DNA and I have ancestry from Alsace-Lorraine (French-Kraut). My mtdna is the same as Queen Victoria's MTDNA. As far as I know England is 53 %Germanic Y-DNA and the rest Celtic Y-DNA but don't quote me on that.

Teutorigos
09-02-2018, 02:11 AM
Out of curiosity, what percent French and German do you get overall?

[Ethnic attack removed by Moderator] 23andme and ancestryDNA are complete garbage except for the raw data. Southern England is no more than 25% German and Anglo-Saxon and kraut are not the samething. Harvard, Yale and Stanford are a joke compared to Oxford and Cambridge as far as I am concerned and the state schools in America are complete joke. If I was born in England I would have went to Cambridge or Oxford for free, probably, since my last name is DeBurgh (Burke) and one generally needs a Norman name to get ahead in England. This information is 100 times more useful than AncestryDNA and 23andME :


Eurogenes K15 :


Eurogenes EUtest V2 K15 Oracle results:
Kit A703943

Admix Results (sorted):

# Population Percent
1 North_Sea 35.89
2 Atlantic 27.28
3 Baltic 9.99
4 Eastern_Euro 9.52
5 West_Med 8.99
6 West_Asian 4.7
...

Single Population Sharing:

# Population (source) Distance
1 Southeast_English 3.84
2 Southwest_English 3.89
3 North_Dutch 4.06
4 Danish 4.39

puntDNAL K12 Modern Oracle results:
puntDNAL K12 Modern Oracle

Kit A703943

Admix Results (sorted):

# Population Percent
1 European_HG 42.24
2 Anatolian_NF 34.06
3 Caucasus_HG 18.94
4 Near_East 1.75
5 Oceanian 1.58
6 South_Asian 0.99
7 South_African_HG 0.24
8 Beringian 0.21

Single Population Sharing:

# Population (source) Distance
1 English_South 2.54

The Stanford university analysis of my DNA (I am the black square notice the German flag and swedish flag by the British flag ?) :

http://img.photobucket.com/albums/v336/naudiz/Screenshot_20170228-050955_zpsejzymy3h.png

I am also somewhat inbred by analysis of my DNA because I am an Anglo-Norman English aristocrat related to the house of York , Windsor and Plantagenet. Last name burke (DeBurgh). John Burke published a peerage book of the landed gentry (last names) of the United States and Great Britain etc... in the 1830s in London. Meet lady Catherine DeBurgh :


https://www.youtube.com/watch?v=aYSdnLgl-FQ

[Irrelevant, off topic. Removed by Moderator]

Moderator
09-02-2018, 08:30 AM
Off topic and racial attacks are contradictory to the Terms of Service. Any more it it will result in sanctions. Final warning.

msmarjoribanks
09-02-2018, 08:35 AM
And LOL about the aristocracy nonsense.

Administrator
09-02-2018, 01:17 PM
Admin

You are correct, 'msmarjoribanks'. The use of any derogatory term isn't welcome in this forum per section 3.10:



3.10 Certain standards of quality control will be enforced to ensure a productive forum atmosphere. Invectives and posts devoid of substance (e.g. threads or replies consisting solely of inflammatory content or triviality) will be considered junk postings and deleted. Breaches in basic forum etiquette include (and are not limited to) cross-posting different threads, consecutive posting in existing threads and reviving old threads whose course of discussion has long since expired ("necro-bumping").


The modified post isn't solely inflammatory or trivial, so that'll remain in place, bar the term in question.

JFWinstone
01-05-2019, 10:07 PM
Since I posted I’ve been dabbling with DNA painter and my mum has several matches on that X chromosome that are 100% East Asian and they are all Taiwanese with roots in Zhejiang, Fujian, Guangdong.

JoeyP37
01-10-2019, 02:49 PM
On 23 and Me, my X chromosome is predominantly British and Irish, with a small snip of Native American (I've named it Elizabeth Warren). My mother's father was entirely English (any non English would have been assimilated Huguenot and at any rate a trickle by his birth in 1931) and her mother's father was of a descent exactly like my X chromosome; he was Virginia settler English with some reputed Native American descent which my X chromosome painting proved.

msmarjoribanks
01-16-2019, 04:20 PM
23andMe is the only X chromosome ancestry source I have.

One of mine is British Isles (good bet that's from my dad, since his mother's ancestry is almost all early colonial American from the British Isles) and the other is about a third British Isles and a third unidentified NW Europe (any part from my mom's dad would have been all Swedish, in fact, since his mother was 100% Swedish, and my mom's mom's part would have been a mix of English/Scots/Irish/German).

I posted this above, and was referring to my Ancestry upload to 23andMe, which is still the same.

However, my actual 23andMe test has one of the X as half British/Irish and half Scandinavian, and the other half British/Irish, half unidentified NW European. Based on some matches, I know the X I got from my mom was half from her dad's Swedish mother, since a second cousin of mine (descended from my g-grandmother's sister) and I match there.

JFWinstone
01-16-2019, 08:15 PM
With the update on 23andme my X gained some Chinese and Broadly SSA segments that were previously unassigned. Mum has large segments of unassigned on the pred European one and the other is mostly Chinese and African.

timberwolf
01-27-2019, 12:05 AM
both of my kits is now French and German.

Jenny
01-27-2019, 08:03 AM
My X is textbook, half Finn from my mother, half Polish from my father's mother

Geborgenheit
02-16-2019, 11:04 AM
My X chromosomes are 100% Eastern European. :)

JerryS.
02-16-2019, 10:38 PM
being a male makes me figuring out my X genes easier than most I figure without a special test. my mom's side was (north) German and Scottish. this all matched up with paper trail, family story, and phenotypes (as well as DNA ethnicity testing).

Shamayim
02-17-2019, 09:03 AM
99% "British & Irish" I guess.

28963

Nino90
02-17-2019, 12:08 PM
I just checked mine. It was all "French and German" With some Sub-Saharan African(I got 0.1%).

Is this real? I mean my mother is 100 % Swedish.

msmarjoribanks
02-21-2019, 07:02 PM
23andMe is the only X chromosome ancestry source I have.

One of mine is British Isles (good bet that's from my dad, since his mother's ancestry is almost all early colonial American from the British Isles) and the other is about a third British Isles and a third unidentified NW Europe (any part from my mom's dad would have been all Swedish, in fact, since his mother was 100% Swedish, and my mom's mom's part would have been a mix of English/Scots/Irish/German).

They updated mine, and now one is all British and Irish, and the other is roughly 40% unidentified NW Europe and 60% Scandinavian. My mother's father's mother (the source of one of her X chromosomes) was 100% Swedish, so that makes sense, and I know I have a significant X match with a 2nd cousin whose father's mother was the same g-grandmother.

msmarjoribanks
02-21-2019, 07:05 PM
I just checked mine. It was all "French and German" With some Sub-Saharan African(I got 0.1%).

Is this real? I mean my mother is 100 % Swedish.

Is this 23andMe? Or are you doing it with Gedmatch? Assuming 23andMe, does it look like some of your Swedish is being reported as French and German? (I know some of the Italian probably gets put in those categories.)

Táltos
02-26-2019, 02:18 AM
One of mine is all Eastern European. The other is Broadly Northwestern Europe, Greek & Balkan, with some Broadly European.

xripkan
04-25-2019, 07:50 PM
According to 23andme I am 92% Southern European and only 7.5% Western Asian. My X Chromosome though is Western Asian.

anglesqueville
04-28-2019, 09:24 AM
According to 23&me, my mother has one X 100% Irish&British, and the other one a mixe of French&German and broadly NW. Mine is 100% Irish&British. Did I inherit the 100% Irish&British, without cross-over? Or the assignation of ethnicities to X segments is not very reliable? Your choice. Of course, I'm phased to my mother.

30122

edit: for laugh, according to FTDNA I have an exact X-match (which is of course impossible) with a man named Tatu Tör***änen, who is ... Finnish.
30123
There are indeed funny things with X chromosomes.

geebee
04-28-2019, 03:19 PM
According to 23&me, my mother has one X 100% Irish&British, and the other one a mixe of French&German and broadly NW. Mine is 100% Irish&British. Did I inherit the 100% Irish&British, without cross-over? Or the assignation of ethnicities to X segments is not very reliable? Your choice. Of course, I'm phased to my mother.

30122

edit: for laugh, according to FTDNA I have an exact X-match (which is of course impossible) with a man named Tatu Tör***änen, who is ... Finnish.
30123
There are indeed funny things with X chromosomes.

In most respects, the X chromosome actually behaves like any similar-sized autosome whenever it can. By "whenever it can", I mean that since a man has only one X chromosome it can't recombine before being passed on. Effectively, it's as if his daughters inherited their paternal X chromosome directly from their paternal grandmother.

Of course, that chromosome could be a recombination of the X chromosomes from both of the great grandparents on that side. (Or it could be from just one of them.)

Two of my own siblings each inherited an X chromosome from our mother that includes DNA only from her father. It isn't unusual for sisters to have one identical X chromosome -- in fact, if they have the same father they always will -- but it's less common for a brother and sister to have an identical X, but these two do. That wouldn't necessarily mean it's just from one grandparent -- though it would need to have identical crossovers if it weren't -- but I've been able to confirm that all of the X chromosome matches my siblings have on this chromosome are to relatives of our paternal grandfather.

I also have an X chromosome that matches theirs pretty closely, except that mine has 20 cM surrounding the centromere that came from our maternal grandmother. Everywhere else I match these two siblings and we all have the same matches to others. In one case, though, we all share a match that extends right through this 20 cM region -- for my siblings, but not for me. In my case, it's two segments. One is on each side of the 20 cM "gap".

However, if your mother doesn't have a tested parent, you can't be sure of the assignment of 100% British & Irish to one X chromosome and the French & German and Northwestern European to the other. It's possible, you just can't tell for sure.

My understanding, though, is that in either Brittany or Normandy it wouldn't be surprising to show quite a bit of "British & Irish" DNA. So the way 23andMe is showing your mother's X chromosomes could be correct; there's just no way to be sure. If it is correct, then it would perhaps suggest that you inherited your X chromosome from just one of your mother's parents. Unfortunately, the only way I think you could determine that is if you have enough matches on your X chromosome that they collectively span the chromosome, and all of the matches can be traced to the same side of your mother's family.

As for there being "funny things with X chromosomes", that's certainly true. For one thing, we have a lot few X-chromosome ancestors than autosomal ancestors. If you were to go back 10 generations, you'd find that you could have as many as 1,024 different ancestors in that generation (2^10). You probably won't, because of pedigree collapse, but this is the maximum number possible.

For the maximum number of possible X chromosome ancestors, though, you have to follow the Fibonacci sequence. You begin with 1, since you're male, so it's (1), 1, 2, 3, 5, 8, 13, 21, 34, 55, 89. Again, this is only the maximum possible number. The actual number could be quite a bit lower. For example, since my brother's X chromosome all came from our maternal grandfather, he can actually begin his there. So instead of my brother's number being 89, it can't be more than 34.

anglesqueville
04-28-2019, 04:34 PM
geebee: about my mother's Irish&Brish X chromosome, it's not really surprising as her father was half British (northern Scotland, from a family with roots mostly in Orkney and Shetland). I presume it's for the same reason that 23&me gives her dots (and me also btw) in Britain only (mostly in Scotland and Northern England). No, what surprised me is the apparent lack of cross-over in the transmission of my own chromosome X. I presume that the only explanation is the uncertainty of ethnic assignation inside NW Europe. Of course, my total ftdna X-match with a Finnish guy (I have many Finnish relatives on ftdna, all through my father's line, but it's another story) is obviously a bug of their database. I wanted to signal it to their staff, but it's still on my to-do-list.

geebee
04-28-2019, 06:33 PM
geebee: about my mother's Irish&Brish X chromosome, it's not really surprising as her father was half British (northern Scotland, from a family with roots mostly in Orkney and Shetland). I presume it's for the same reason that 23&me gives her dots (and me also btw) in Britain only (mostly in Scotland and Northern England). No, what surprised me is the apparent lack of cross-over in the transmission of my own chromosome X. I presume that the only explanation is the uncertainty of ethnic assignation inside NW Europe. Of course, my total ftdna X-match with a Finnish guy (I have many Finnish relatives on ftdna, all through my father's line, but it's another story) is obviously a bug of their database. I wanted to signal it to their staff, but it's still on my to-do-list.

Okay. I'd just say that if it really is the case that she transmitted an unrecombined X chromosome to you, that really isn't too unusual. I don't know what proportion of the time this happens, but it isn't "rare". In fact, it doesn't just happen for the X chromosome. Sometimes, even autosomes will be passed on without any apparent recombination.

As a specific example, my daughter's paternal chromosomes 9, 13, and 21 appear to be perfect matches for my own paternal chromosomes 9, 13, 21 -- meaning there was no recombination with my maternal copy of each of these chromosomes.

On the other side, my daughter doesn't match my father at all on chromosomes 7, 15, 17, 18, 22 -- or, of course, the X chromosome. So it looks as if these 6 chromosomes are all from my mother, with no crossovers with the copies from my father.

That makes 9 out of 23 chromosomes passed on unrecombined from me to my daughter. Even if you exclude the X chromosome -- where of course I only have one copy -- that still means it's a bit more than 1/3 of the chromosomes. My father has four other tested grandchildren, and all but one of them appears to have inherited at least one unrecombined autosome. My oldest brother's daughter completely matches her paternal grandfather on two autosomes (16 and 20), and shares nothing at all with him on chromosomes 19 and 21.

Also, because she inherited her father's X chromosome, I match her on the X in exactly the same way I match her father -- for all but that 20 cM region around the centromere that I mentioned in a previous post. Likewise, my daughter matches this cousin on the X the same way I match my brother.

Since one of my sisters matches my brother's entire X, that sister also matches our brother's daughter's paternal X completely. Presumably, if we could test my mother's father, we'd see that my niece matches him completely on the X chromosome, so we'd have a case of an X being passed on from great grandparent to great grandchild with no change. Since my niece has 5 children, it's entirely possible that one of these could have an "intact" X chromosome that has experience no recombination since their great, great grandfather -- which also means it would all come from the same 3rd great grandmother, though it could be from both of her parents.

anglesqueville
04-28-2019, 07:53 PM
I don't know what proportion of the time this happens, but it isn't "rare". In fact, it doesn't just happen for the X chromosome. Sometimes, even autosomes will be passed on without any apparent recombination.

Really? It's new to me, I was convinced that any pair of chromosomes were affected by the cross-over at each generation. Very interesting. Thanks.

MacUalraig
04-28-2019, 08:25 PM
Really? It's new to me, I was convinced that any pair of chromosomes were affected by the cross-over at each generation. Very interesting. Thanks.

Blaine Bettinger did a survey on this topic and claimed 14% showed zero recombination on the X:

https://thegeneticgenealogist.com/wp-content/uploads/2017/02/Recombination_Preprint.pdf

JerryS.
04-28-2019, 08:27 PM
I have a question about X being passed to a son then passed to another son...…

My paternal grandma passed her X combined but mostly presumably 75% from a certain region. she passes her X to her sons (my dad and uncle). My dad passes his Y from a different region to me, while my uncle passes his X to his daughter (my 1st cousin) basically unchanged(?) from his mom (my grandma). I am not mixed racially but I am mixed regionally. how much of my paternal grandma's X will I have attached to my dad's Y and how much of my grandma's X will my cousin have roughly?

Pylsteen
04-28-2019, 09:08 PM
Blaine Bettinger did a survey on this topic and claimed 14% showed zero recombination on the X:

https://thegeneticgenealogist.com/wp-content/uploads/2017/02/Recombination_Preprint.pdf

Very interesting. There are many types of crossing-over; what I find interesting is that the amount of crossing-overs transmitted by fathers is lower than that by mothers; this creates larger (but less) paternal matches and smaller (but more) maternal ones.

If I look at my own case, on my father's side, I see that chromosome 14 is in its entirety from my grandfather, and chromosome 22 in its entirety from my grandmother (judging DNA matches it must even be from her great grandfather in its entirety (!)).
When they do recombine, it is often not really half/half, but more like 1/3 vs 2/3 or "body" vs "tips". My chromosome 2 is almost entirely from my grandfather, except for one tip. Because of this chunky recombination I have about 27,5% from my grandfather and 22,5% from my grandmother.

Unfortunately no good X-chromosome matches at the moment; I hope that MyHeritage, where I have the most useful matches, will unroll X-matching at some point. I expect to see Dutch and/or Belgian and/or German X-matches.

JerryS.
04-29-2019, 04:38 AM
folks, humor me if you can. I am far from being well read in all this. my question above has a reason behind it for me. if what I'm asking is senseless please say so. as I understand things, while you inherit roughly a 50/50 split from your parents, you don't necessarily inherit 50% of what each one has.

geebee
04-30-2019, 07:28 PM
folks, humor me if you can. I am far from being well read in all this. my question above has a reason behind it for me. if what I'm asking is senseless please say so. as I understand things, while you inherit roughly a 50/50 split from your parents, you don't necessarily inherit 50% of what each one has.

You're right about parents contributing roughly 50/50 to their children's DNA. Essentially, there are only two reasons it's "roughly" rather than exactly. First, the significant size difference between the X and Y chromosomes means that mothers contribute a little more DNA to their sons than their fathers do. With daughters, the contribution is virtually the same -- at least when it comes to nuclear DNA. This brings us to the other reasons it isn't a 50/50 split -- the fact that whether you're male or female, your mtDNA is all from your mother.

With grandparents and beyond, the actual contribution can vary enormously. For example, maybe your maternal grandfather's contribution is actually only 20%. Your maternal grandparents together have the same total as your mother -- 50% -- so that would mean your maternal grandmother's contribution must be 30%.

Here's a real world example. My sister's sharing with her grandson is 21.5%. Since my father's sharing with this same great grandson is only 7.34%, we can calculate my mother's sharing as 21.5% - 7.34%, or 14.16%. Or to put it a little differently, my mother shares almost twice as much DNA with this great grandson as my father does.

Because of these differences, the amount of DNA we inherit from ancestors in the same generation can vary quite a bit. In fact, with 3rd great grandparents and beyond, it's entirely possible to share no DNA at all with some of them. (Obviously, as a group your 3rd great grandparents still have to account for 100% of your DNA, and the same thing is true for 6th great grandparents and beyond.)

The key thing to remember, though, is that ancestry is based on ancestors. So regardless of how good a company may be at estimating what ancestry a particular stretch of DNA might reflect, it's also a matter of how much DNA you actually inherited from the specific ancestors who have reflect that ancestry.

JerryS.
04-30-2019, 07:48 PM
You're right about parents contributing roughly 50/50 to their children's DNA. Essentially, there are only two reasons it's "roughly" rather than exactly. First, the significant size difference between the X and Y chromosomes means that mothers contribute a little more DNA to their sons than their fathers do. With daughters, the contribution is virtually the same -- at least when it comes to nuclear DNA. This brings us to the other reasons it isn't a 50/50 split -- the fact that whether you're male or female, your mtDNA is all from your mother.

With grandparents and beyond, the actual contribution can vary enormously. For example, maybe your maternal grandfather's contribution is actually only 20%. Your maternal grandparents together have the same total as your mother -- 50% -- so that would mean your maternal grandmother's contribution must be 30%.

Here's a real world example. My sister's sharing with her grandson is 21.5%. Since my father's sharing with this same great grandson is only 7.34%, we can calculate my mother's sharing as 21.5% - 7.34%, or 14.16%. Or to put it a little differently, my mother shares almost twice as much DNA with this great grandson as my father does.

Because of these differences, the amount of DNA we inherit from ancestors in the same generation can vary quite a bit. In fact, with 3rd great grandparents and beyond, it's entirely possible to share no DNA at all with some of them. (Obviously, as a group your 3rd great grandparents still have to account for 100% of your DNA, and the same thing is true for 6th great grandparents and beyond.)

The key thing to remember, though, is that ancestry is based on ancestors. So regardless of how good a company may be at estimating what ancestry a particular stretch of DNA might reflect, it's also a matter of how much DNA you actually inherited from the specific ancestors who have reflect that ancestry.

so my female 1st cousin would probably have received more of our paternal grandmother's DNA via her dad passing the X chromosome from his mom (my grandmother) to his daughter my 1st cousin), while I would have inherited a bit less because my link to my paternal grandmother is from my father's Y chromosome? not meaning relationship wise but ethnicity/admixture stuff.

geebee
05-01-2019, 03:12 AM
so my female 1st cousin would probably have received more of our paternal grandmother's DNA via her dad passing the X chromosome from his mom (my grandmother) to his daughter my 1st cousin), while I would have inherited a bit less because my link to my paternal grandmother is from my father's Y chromosome? not meaning relationship wise but ethnicity/admixture stuff.

Well, I wouldn't say your father's Y is any sort of link to your paternal grandmother, since what he inherited from her was an X chromosome. He didn't pass that on to you, of course, but if you have any sisters (unless they're maternal half sisters), he did pass that X on to them. Your Y chromosome is only a link to your father, and your paternal grandfather, and your grandfather's father, and so on into the very distant past.

As to your sharing with your paternal grandmother versus your 1st cousin's, it isn't necessarily the case that she shares more. You might share enough more autosomal DNA with her to overcome the advantage of sharing an X chromosome. However, since your cousin doesn't just share a segment or two of the X chromosome with your grandmother, but the entire X chromosome, I'd say she probably has the edge.

JerryS.
05-01-2019, 12:17 PM
Well, I wouldn't say your father's Y is any sort of link to your paternal grandmother, since what he inherited from her was an X chromosome. He didn't pass that on to you, of course, but if you have any sisters (unless they're maternal half sisters), he did pass that X on to them. Your Y chromosome is only a link to your father, and your paternal grandfather, and your grandfather's father, and so on into the very distant past.

As to your sharing with your paternal grandmother versus your 1st cousin's, it isn't necessarily the case that she shares more. You might share enough more autosomal DNA with her to overcome the advantage of sharing an X chromosome. However, since your cousin doesn't just share a segment or two of the X chromosome with your grandmother, but the entire X chromosome, I'd say she probably has the edge.

thank you for the insight. its sort of how I figured things....

msmarjoribanks
05-02-2019, 10:19 PM
I have a question about X being passed to a son then passed to another son...…

My paternal grandma passed her X combined but mostly presumably 75% from a certain region. she passes her X to her sons (my dad and uncle). My dad passes his Y from a different region to me, while my uncle passes his X to his daughter (my 1st cousin) basically unchanged(?) from his mom (my grandma). I am not mixed racially but I am mixed regionally. how much of my paternal grandma's X will I have attached to my dad's Y and how much of my grandma's X will my cousin have roughly?

You will not have any of your paternal grandmother's X. Your X would be solely from your mother, but would have unknown amounts from her mother and father (your maternal grandparents). Whatever part she got from her father would come from his mother and not his father (her paternal grandmother), but the part she got from her mother could (and likely would) have parts from both of her maternal grandparents.

Your female cousins from your father's brother will have X from both their parents, but would not normally be an X match for you.

JerryS.
05-02-2019, 11:44 PM
You will not have any of your paternal grandmother's X. Your X would be solely from your mother, but would have unknown amounts from her mother and father (your maternal grandparents). Whatever part she got from her father would come from his mother and not his father (her paternal grandmother), but the part she got from her mother could (and likely would) have parts from both of her maternal grandparents.

Your female cousins from your father's brother will have X from both their parents, but would not normally be an X match for you.

right, I know that my X comes from my mom who is not related to my cousin in any fashion, while both of her's [my cousin] come from her dad [my uncle] and mom. just as her X comes from her dad [my uncle] via his mom [our grandma], both of whom I am related but do not share any X. while my Y comes from my dad [my cousin's uncle] via his dad [our grandpa] which she does not share any Y with. that was never in question. what I was asking is how much more of our grandma's DNA will my cousin have over me since she [grandma] passed down her X to her which I did not get.

msmarjoribanks
05-03-2019, 01:13 AM
Ah -- no way to tell.

geebee
05-12-2019, 06:36 AM
right, I know that my X comes from my mom who is not related to my cousin in any fashion, while both of her's [my cousin] come from her dad [my uncle] and mom. just as her X comes from her dad [my uncle] via his mom [our grandma], both of whom I am related but do not share any X. while my Y comes from my dad [my cousin's uncle] via his dad [our grandpa] which she does not share any Y with. that was never in question. what I was asking is how much more of our grandma's DNA will my cousin have over me since she [grandma] passed down her X to her which I did not get.

I'm not sure what you're asking. Obviously, you know that you received 0% of your paternal grandmother's two X chromosomes. Your cousin, since she is also paternally related to this grandmother, received 50% of the grandmother's two X chromosomes -- the same 50% that her father received. [But note that 50% of your grandmother's two X chromosomes is equivalent to 100% of your cousin's paternal X chromosome -- so your cousin received one entire X chromosome more from your grandmother than you did, since you received none.)

What we don't know at this point is how much of that came from your grandmother's father and how much came from your grandmother's mother. It's possible that your cousin's X chromosome is entirely from just one of your grandmother's parents. But whatever the case, your cousin received a complete X chromosome from her paternal grandmother, versus no paternal X for you.

As I mentioned in another post, two of my mother's six offspring inherited a maternal X chromosome that is 100% from her father. The other four inherited a maternal X chromosome that's a recombination of both of our mother's X chromosomes. My sisters, of course, also inherited identical copies of our father's only X chromosome.

JerryS.
05-12-2019, 07:01 AM
I'm not sure what you're asking. Obviously, you know that you received 0% of your paternal grandmother's two X chromosomes. Your cousin, since she is also paternally related to this grandmother, received 50% of the grandmother's two X chromosomes -- the same 50% that her father received. [But note that 50% of your grandmother's two X chromosomes is equivalent to 100% of your cousin's paternal X chromosome -- so your cousin received one entire X chromosome more from your grandmother than you did, since you received none.)

What we don't know at this point is how much of that came from your grandmother's father and how much came from your grandmother's mother. It's possible that your cousin's X chromosome is entirely from just one of your grandmother's parents. But whatever the case, your cousin received a complete X chromosome from her paternal grandmother, versus no paternal X for you.

As I mentioned in another post, two of my mother's six offspring inherited a maternal X chromosome that is 100% from her father. The other four inherited a maternal X chromosome that's a recombination of both of our mother's X chromosomes. My sisters, of course, also inherited identical copies of our father's only X chromosome.

I know my cousin received some of our grandmother's X and I received none. I'm just wondering how much influence my grandma's X had on my father's Y which I got.

Táltos
05-13-2019, 04:16 PM
I know my cousin received some of our grandmother's X and I received none. I'm just wondering how much influence my grandma's X had on my father's Y which I got.

Is this what you are asking?

The pseudoautosomal regions (PAR1 and PAR2) are short regions of homology between the mammalian X and Y chromosomes. The PAR behave like an autosome and recombine during meiosis. Thus genes in this region are inherited in an autosomal rather than a strictly sex-linked fashion.

PAR1 comprises 2.6 Mb of the short-arm tips of both X and Y chromosomes in humans and other great apes [7, 8] and is required for pairing of the X and Y chromosomes during male meiosis. All characterized genes within PAR1 escape X inactivation. X-Y pairing in the PAR is thought to serve a critical function in spermatogenesis, at least in humans and mouse [9–11]. PAR2 is located at the tips of the long arms and is a much shorter region, spanning only 320 kb [12]. PAR2 exhibits a much lower frequency of pairing and recombination than PAR1 and is not necessary for fertility [13–15]. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2435358/

JerryS.
05-13-2019, 10:55 PM
Is this what you are asking?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2435358/

sister, you really went over my head with that one. LOL. but, I think if I decoded that, yeah. how much of my father's Y is/was effected by his mother's X and how much of that would I have gotten, generally speaking of course. in other words, how much of my paternal grandma's ethnicity did I inherit, generally speaking?

geebee
05-14-2019, 01:24 AM
I know my cousin received some of our grandmother's X and I received none. I'm just wondering how much influence my grandma's X had on my father's Y which I got.

Your grandma's X had no influence on your father's Y. His Y chromosome came 100% from his father, and therefore could have had no influence from his mother. But I suppose what you're really asking is how much influence your father's X chromosome -- which, of course, did come from his mother -- might have had on the Y chromosome he passed on to you.

The answer is, not much. The only places where your father's X and Y chromosomes could have recombined are at the tips of the chromosomes. So, your father might have passed on to you a Y chromosome that contained a little bit of his X chromosome in these locations.

The locations are PAR1 and PAR2, where PAR stands for "pseudoautosomal recombining region". From memory, PAR1 is something like 1.6 cM in length , and PAR2 is only about 0.32 cM in length. 23andMe does test some SNPs in each of these regions, but they report both SNPs at each location (one on the X chromosome and one on the Y chromosome) as if these SNPs were only on the X chromosome. After all, that's how they would be in women -- the SNPs from PAR1 and PAR2 would be on the two X chromosomes.

In men, of course, one SNP at each tested location in PAR1 and PAR2 would actually be on the X chromosome, and one would be on the Y chromosome. You might in some cases be able to figure out which is which if either your father or your mother has tested. The trouble is, I don't see how you could determine which SNP came originally from your father's X chromosome and which came from his Y chromosome unless one of [I]his parents tested.

Of course, for any location that is homozygous for either you or your father (if you've both tested), you can tell which SNP you must have inherited from your father. But if both of you are heterozygous at a given location, you won't be able to tell which SNP came from which parent. And again, even if you can figure out which came from your father -- you'd still have to figure out if it came from his X chromosome or his Y chromosome.

As I said, though, the contribution from your grandmother can't be much in any case. At most, your father's contribution at PAR1 (2.6 cM max) and his contribution at PAR2 (0.32 cM max) could be from his X chromosome.

EDIT: Found my source and corrected the amount for PAR1. https://en.wikipedia.org/wiki/Pseudoautosomal_region

geebee
05-14-2019, 02:59 PM
sister, you really went over my head with that one. LOL. but, I think if I decoded that, yeah. how much of my father's Y is/was effected by his mother's X and how much of that would I have gotten, generally speaking of course. in other words, how much of my paternal grandma's ethnicity did I inherit, generally speaking?

It's always possible that you inherited more DNA from your paternal grandma than from any other parent -- but not from her X chromosome. Your father inherited an entire X chromosome from her, but he didn't pass it on to you -- other than (possibly) at those tips I mentioned.

However, you did inherit autosomal DNA from your father's mother. I don't think you're likely to be able to figure out just how much, unless either of your paternal grandparents has been or could be tested. Or, you might possibly be able to figure it out if you have cousins who are only on her side. Whatever you share with them is likely to be in a region that came from her.

For example, I can identify several segments that must have come from my paternal grandmother because I share these segments with several half 2nd cousins on my grandmother's father's side. They are not, as far as I can tell, related to me in any other way.

When it comes to my X chromosome, I know that all but 20 cM of it is from my maternal grandfather (and therefore his mother). The "extra" SNPs on my X chromosome -- since I actually only have one copy -- must be from my Y chromosome, even though they're reported with the X. But they're too small to have much -- if any -- impact on the ancestry painting of my X chromosome.

In a way, the most accurate way of depicting men's X chromosomes in Ancestry Composition would be to report one whole chromosome and two fragments of a second X chromosome. Or maybe just one fractment, PAR1, since 23andMe does report some segments of 2.6 cM in length. I don't think 0.32 cM would even register.

Of course, the Y chromosome is not even used in Ancestry Composition, possibly because it undergoes no recombination. I say that in spite of knowing that it does recombine, at PAR1 and PAR2; but remember that these ends are not included with the Y at most companies -- but with the X. So what is reported as your Y chromosome is actually a truncated version, without the very tips (PAR1 and PAR2).

But the bottom line is that for the purpose of determining the "ethnic origins" of your X chromosome, it doesn't point to anyone but your mother and her ancestors, even though you could have a tiny input from your father here. The input won't be to the X you received from your mother, of course, but in the two PAR regions you effectively have a 2nd X chromosome -- though it doesn't appear in the painting.

If an ancestry painting is affected at all -- regardless of whether it's at 23andMe or elsewhere -- it has to be pretty negligible. I suspect, undetectible.

JerryS.
05-17-2019, 11:02 PM
It's always possible that you inherited more DNA from your paternal grandma than from any other parent -- but not from her X chromosome. Your father inherited an entire X chromosome from her, but he didn't pass it on to you -- other than (possibly) at those tips I mentioned.

However, you did inherit autosomal DNA from your father's mother. I don't think you're likely to be able to figure out just how much, unless either of your paternal grandparents has been or could be tested. Or, you might possibly be able to figure it out if you have cousins who are only on her side. Whatever you share with them is likely to be in a region that came from her.

For example, I can identify several segments that must have come from my paternal grandmother because I share these segments with several half 2nd cousins on my grandmother's father's side. They are not, as far as I can tell, related to me in any other way.

When it comes to my X chromosome, I know that all but 20 cM of it is from my maternal grandfather (and therefore his mother). The "extra" SNPs on my X chromosome -- since I actually only have one copy -- must be from my Y chromosome, even though they're reported with the X. But they're too small to have much -- if any -- impact on the ancestry painting of my X chromosome.

In a way, the most accurate way of depicting men's X chromosomes in Ancestry Composition would be to report one whole chromosome and two fragments of a second X chromosome. Or maybe just one fractment, PAR1, since 23andMe does report some segments of 2.6 cM in length. I don't think 0.32 cM would even register.

Of course, the Y chromosome is not even used in Ancestry Composition, possibly because it undergoes no recombination. I say that in spite of knowing that it does recombine, at PAR1 and PAR2; but remember that these ends are not included with the Y at most companies -- but with the X. So what is reported as your Y chromosome is actually a truncated version, without the very tips (PAR1 and PAR2).

But the bottom line is that for the purpose of determining the "ethnic origins" of your X chromosome, it doesn't point to anyone but your mother and her ancestors, even though you could have a tiny input from your father here. The input won't be to the X you received from your mother, of course, but in the two PAR regions you effectively have a 2nd X chromosome -- though it doesn't appear in the painting.

If an ancestry painting is affected at all -- regardless of whether it's at 23andMe or elsewhere -- it has to be pretty negligible. I suspect, undetectible.

that said, I did however receive abut 25% on my autosomal DNA from her, correct?

geebee
05-18-2019, 04:34 AM
that said, I did however receive abut 25% on my autosomal DNA from her, correct?

Yeah, that's likely. Or, say, something between about 20-30%. The total contribution of each pair of grandparents has to equal the contribution of the parent on that side, but in theory for each grandparent it could be anything from 0-50%. However, I doubt that anyone's ever actually seen a case in which a grandparent contributed either 0 or 50% to a grandchild. It would require every single chromosome from one parent to be passed on with no recombination, and all from the same grandparent. (So obviously the other grandparent would contribute nothing.)

However, it routinely happens that a few chromosomes will be passed on from one grandparent or another, with no contribution from the opposite grandparent. For example, my father and daughter share across the entirety of chromosomes 9 and 21; and they share no part of chromosomes 7, 15, 17, 18, 22, or -- of course -- the X chromosome. So my daughter's paternal copy of chromosomes 9 and 21 are the same as my paternal copy of these chromosomes; and her paternal copy of chromosomes 7, 15, 18, 22, and the X chromosome are the same as my maternal copy of each of these. (Of course, with the X I only have a maternal copy.)

My father has four other tested grandchildren, so I can see that my daughter is not the only one of his grandchildren to inherit some apparently "unrecombined" chromosomes. For example, my brother's son inherited all (or very nearly all; it's difficult to be sure) of my father's chromosomes 3 and 7. He inherited nothing from my father's chromosomes 4, 9, 12, 13, 18, 19, 21, or his X chromosome.

In terms of percentages, here are the percentages each tested grandchild received from my father:

My oldest brother's daughter -- 25.4%
His son -- 18.5%

My oldest sister's daughter -- 20.4%
Her son -- 28.0%

My daughter -- 22.5%

By this you can actually see that only one of the five inherited within a percent of 25%. One grandson inherited even less than the 20% I mentioned above, so obviously these aren't hard and fast numbers. There are parents who have very low crossover rates, which could result in a grandchild inheriting either a very high or very low percentage from the parent's parents. In fact, if they inherit a low percentage from one, they'll necessarily inherit a high percentage from the other -- because the total has to add up to 50%.

As a "bonus", I'll also tell you about my dad's sharing with his tested [I]great grandson -- the son of my sister's daughter. The shared amount is 7.34%, which is a lot lower than the "expected" 12.5% for great grandparents. My sister's sharing with her grandson is not 25%, but actually only 21.5%. So presumably he shares more DNA with his mother's father, since the total should add up to 50%.

Obviously, my parents' total contribution to their great grandson's DNA has to equal my sister's contribution, so my mother's contribution should be equal to 21.5% minus my father's contribution of 7.34%, or 14.16%. In other words, my sister's grandson inherited almost twice as much DNA from his maternal grandmother's mother as he did from his maternal grandmother's father.

The bottom line is, you almost certainly inherited something close to 25% from your grandmother, but you can see that it could be anything from a bit less than 20% to a bit over 30%. In fact, I'll revise my 20%-30% to maybe 15-35%, which some exceptional cases that fall even outside this range. But again, both grandparents on a side together will contribute 50%.

JerryS.
05-18-2019, 06:05 PM
Yeah, that's likely. Or, say, something between about 20-30%. The total contribution of each pair of grandparents has to equal the contribution of the parent on that side, but in theory for each grandparent it could be anything from 0-50%. However, I doubt that anyone's ever actually seen a case in which a grandparent contributed either 0 or 50% to a grandchild. It would require every single chromosome from one parent to be passed on with no recombination, and all from the same grandparent. (So obviously the other grandparent would contribute nothing.)

However, it routinely happens that a few chromosomes will be passed on from one grandparent or another, with no contribution from the opposite grandparent. For example, my father and daughter share across the entirety of chromosomes 9 and 21; and they share no part of chromosomes 7, 15, 17, 18, 22, or -- of course -- the X chromosome. So my daughter's paternal copy of chromosomes 9 and 21 are the same as my paternal copy of these chromosomes; and her paternal copy of chromosomes 7, 15, 18, 22, and the X chromosome are the same as my maternal copy of each of these. (Of course, with the X I only have a maternal copy.)

My father has four other tested grandchildren, so I can see that my daughter is not the only one of his grandchildren to inherit some apparently "unrecombined" chromosomes. For example, my brother's son inherited all (or very nearly all; it's difficult to be sure) of my father's chromosomes 3 and 7. He inherited nothing from my father's chromosomes 4, 9, 12, 13, 18, 19, 21, or his X chromosome.

In terms of percentages, here are the percentages each tested grandchild received from my father:

My oldest brother's daughter -- 25.4%
His son -- 18.5%

My oldest sister's daughter -- 20.4%
Her son -- 28.0%

My daughter -- 22.5%

By this you can actually see that only one of the five inherited within a percent of 25%. One grandson inherited even less than the 20% I mentioned above, so obviously these aren't hard and fast numbers. There are parents who have very low crossover rates, which could result in a grandchild inheriting either a very high or very low percentage from the parent's parents. In fact, if they inherit a low percentage from one, they'll necessarily inherit a high percentage from the other -- because the total has to add up to 50%.

As a "bonus", I'll also tell you about my dad's sharing with his tested [I]great grandson -- the son of my sister's daughter. The shared amount is 7.34%, which is a lot lower than the "expected" 12.5% for great grandparents. My sister's sharing with her grandson is not 25%, but actually only 21.5%. So presumably he shares more DNA with his mother's father, since the total should add up to 50%.

Obviously, my parents' total contribution to their great grandson's DNA has to equal my sister's contribution, so my mother's contribution should be equal to 21.5% minus my father's contribution of 7.34%, or 14.16%. In other words, my sister's grandson inherited almost twice as much DNA from his maternal grandmother's mother as he did from his maternal grandmother's father.

The bottom line is, you almost certainly inherited something close to 25% from your grandmother, but you can see that it could be anything from a bit less than 20% to a bit over 30%. In fact, I'll revise my 20%-30% to maybe 15-35%, which some exceptional cases that fall even outside this range. But again, both grandparents on a side together will contribute 50%.

this really explains it well. thank you so much for this as well as the real world examples you've given. so (not always but usually) if I inherit 25% of my DNA from my grandmother and she was 25% white and 75% black I would be 18.75% black? (just using the strict math) she wasn't and I'm not but just using that as an example to simplify this...

Amber29
06-19-2019, 05:53 PM
Hi guys,

I am new to this X chromosome thing, i used to ignore it till i got my mother tested and even though as I wasnt sure how to deal with it.

I am of South Asian background, but me and mother get different matches, but around similar ethnicities of european such spanish/portuguese/western asian mix (not sure which sides is being picked up but another match mother has and both have in common in spanish (as im getting alot of these along with british and irish and eastern european autosomally) and british irish and ofcourse south asian.

its around in the same area of X chromosome and they segments range around 12cM to 23cM.

today I got one match 6cM on 8 and 20cM on X

I dont know much about my past history, being south asians we dont have records - or in some cases due to alot of politics maybe have been destroyed and no one has been told we had so and so ancestors - (if it was a big thing then so and so ancestors would have been passed down the generations)

I dont know what I am asking for here as I dont know what to think and im asking for help.

I show no european ancestry on 23andme but i get 4 to 6% british/irish - on some occasion eastern european but on gedmatch i do seem balkans/southern european and other northwest/east european.

but mother shows some strong dodecad kb7 mainly around 5% of basque spanish portuguese and what not. I am finding it hard to believe, but same time I want to know how can i tell if its recent or if its just steppe related? (most asians do have steppe related) sometimes I also think , that my MTDNA is also european when i see all these results (but could be neolithic etc could have happened any given time)

hope this helps with informationswhat my mind is going through for you guys to understand - what I want to ask for..

Thanks.

geebee
06-20-2019, 09:08 PM
Since we're talking about the X chromosome here, you probably are aware that as a female you inherited one copy from each parent. Since your father only has one copy -- from his mother -- your copy from him should match that copy completely.

With your mother it's a different story. Since she has two copies, there were three possibilities for the X chromosome you inherited from her. It could be: (1) 100% from her father; (2) 100% from her mother; or (3) a recombination of both copies of her X chromosome.

Possibility number #3 is generally the mostly likely, but both #1 and #3 occur with some regularity. For example, out of my three full sisters, one inherited a maternal X chromosome that came solely from our mother's father. The other two each inherited a maternal X chromosome that included DNA from each of our mother's parents.

Naturally, my three sisters also inherited a paternal X chromosome. They match on this one, since it includes DNA only from our father's mother.

What that means is, you can have X chromosome matches that your mother does not. As long as these are reasonably large segments -- say, more than 10 cM -- then the segment is almost certainly on your father's side. Smaller segments from the X chromosome are more uncertain, especially if they're shared between to women. If shared between a woman and a man, they're a little more certain; and if between two men they're more certain yet. (This is because the two men only have one X chromosome each to compare, whereas two women each have two X chromosomes to compare -- therefore increasing the chance of a match which is "identical by chance".)

Your 20 cM match is probably large enough to be worth looking into, but if the person you match only has an autosomal match of 6 cM, then your most recent common ancestors could be somewhat distant. There are two things to remember:

(1) Every time an X chromosome is passed on (always to a daughter), there is no other X chromosome to recombine with so it's as if it "skipped a generation".

(2) Sometimes even a maternal X chromosome is passed on without recombination, as I mentioned above.

If you contact your match, and they know their family tree pretty well, it might be possible to figure out the possible paths for that person's X chromosome DNA. You may also be able to figure out the path on your side.

For example, even females can rule out one path right away: your father's father. Males can rule out two paths: both of their father's parents. Sometimes, you can rule out more. For example, my sister can not only rule out our father's father as being in her X paths, she can also rule out our mother's mother -- since we know that her maternal X chromosome is entirely from our mother's father (which also means it's entirely from his mother).

Since your mother has also tested at 23andMe, as long as your results are linked then you should be able to look at Ancestry Composition and see where the segments are from each parent. Your results from 23andMe should probably be the most reliable you can get for now, since they're using "phased" data for you if your mother's results are linked.

By "phased" I mean that by comparing your results to your mother's, 23andMe can tell what DNA came from each parent. Without phasing, they can't. Most other companies use unphased data -- and this applies, for example, to GEDmatch.

Amber29
06-20-2019, 10:10 PM
Since we're talking about the X chromosome here, you probably are aware that as a female you inherited one copy from each parent. Since your father only has one copy -- from his mother -- your copy from him should match that copy completely.

With your mother it's a different story. Since she has two copies, there were three possibilities for the X chromosome you inherited from her. It could be: (1) 100% from her father; (2) 100% from her mother; or (3) a recombination of both copies of her X chromosome.

Possibility number #3 is generally the mostly likely, but both #1 and #3 occur with some regularity. For example, out of my three full sisters, one inherited a maternal X chromosome that came solely from our mother's father. The other two each inherited a maternal X chromosome that included DNA from each of our mother's parents.

Naturally, my three sisters also inherited a paternal X chromosome. They match on this one, since it includes DNA only from our father's mother.

What that means is, you can have X chromosome matches that your mother does not. As long as these are reasonably large segments -- say, more than 10 cM -- then the segment is almost certainly on your father's side. Smaller segments from the X chromosome are more uncertain, especially if they're shared between to women. If shared between a woman and a man, they're a little more certain; and if between two men they're more certain yet. (This is because the two men only have one X chromosome each to compare, whereas two women each have two X chromosomes to compare -- therefore increasing the chance of a match which is "identical by chance".)

Your 20 cM match is probably large enough to be worth looking into, but if the person you match only has an autosomal match of 6 cM, then your most recent common ancestors could be somewhat distant. There are two things to remember:

(1) Every time an X chromosome is passed on (always to a daughter), there is no other X chromosome to recombine with so it's as if it "skipped a generation".

(2) Sometimes even a maternal X chromosome is passed on without recombination, as I mentioned above.

If you contact your match, and they know their family tree pretty well, it might be possible to figure out the possible paths for that person's X chromosome DNA. You may also be able to figure out the path on your side.

For example, even females can rule out one path right away: your father's father. Males can rule out two paths: both of their father's parents. Sometimes, you can rule out more. For example, my sister can not only rule out our father's father as being in her X paths, she can also rule out our mother's mother -- since we know that her maternal X chromosome is entirely from our mother's father (which also means it's entirely from his mother).

Since your mother has also tested at 23andMe, as long as your results are linked then you should be able to look at Ancestry Composition and see where the segments are from each parent. Your results from 23andMe should probably be the most reliable you can get for now, since they're using "phased" data for you if your mother's results are linked.

By "phased" I mean that by comparing your results to your mother's, 23andMe can tell what DNA came from each parent. Without phasing, they can't. Most other companies use unphased data -- and this applies, for example, to GEDmatch.

Thanks for this information I am going to refer back to this as a reminder when i need this advice at the time when looking invidually for future reference - only difference is me and mum show 99% South Asian and she scores 0.4% western asian and north african - so it hasnt been entirely accurate for me to find out any segment from each chromosome. Even X chromosome shows all south asian

geebee
06-21-2019, 01:07 AM
Yes, if both of your mother's X chromosomes show as completely South Asian, then your maternal X chromosome should only be South Asian ... except, that 23andMe says that the results for people with at least one linked parent are usually a bit more accurate than for someone with no linked parent.

So in theory, your Ancestry Composition should be a bit more accurate overall than your mother's. But, I'd still think that if your mother has only South Asian on either X, that's what you should have on your maternal X.

For your paternal X, it's a different story. You should have on that X exactly what your father has (if he tested).

Also, generally if a person does have a linked parent, then the top half of each pair of chromosomes should be for the mother, and the bottom half for the father (even if only one of the parents took the test). But be aware than on occasion they can still show very small segments in the wrong place. (So they think it's from the opposite parent than the one it really came from.) This doesn't happen often, but once in a while.

Amber29
06-21-2019, 06:27 AM
So should i on this occasion that these specific european matches im getting was mixed with an south asian and only a south asian segment carried on with X and that how im getting these X? Because they literally show no south asian either only one did but at 4% the other ones didnt. I actually get different results 23andme doesnt break down the asian components that why i find it not accurate - atleast in the myheritage it showed me mixture and living dna and gedmatch is spot on and fits in line with dna matches.

I was phased with my father who got 100 but even the dna matches doesnr even relate to his ancestry other than gedmatch which fits in. Hmmm

I have found out dads x matches thankfully was able to traxe some families. But im getting my grandparenrs tests in Pakistan from FTDNA hopefully shows something for me to find out ... thanks!

Amber29
06-21-2019, 06:28 AM
Double post

msmarjoribanks
07-28-2019, 10:06 PM
I posted this above, and was referring to my Ancestry upload to 23andMe, which is still the same.

However, my actual 23andMe test has one of the X as half British/Irish and half Scandinavian, and the other half British/Irish, half unidentified NW European. Based on some matches, I know the X I got from my mom was half from her dad's Swedish mother, since a second cousin of mine (descended from my g-grandmother's sister) and I match there.

Updating this, I've been working on DNA painter. As expected, one of my mom's X chromosomes (that from her dad) should be entirely from his Swedish mom, and that seems to be the case.

However, my own X (from my mom) seems to get the first quarter from my maternal grandmother, and then the rest largely from her dad. But at 23andMe one of my X chromosomes shows the first half (bit more, really) and not the second as Scandinavian. That necessarily includes either the part from my dad or from my mom's mom, both of which are not Scandinavian but most likely English. 23andMe shows 100% of my other X as English and Irish (likely true for my dad's) and then the second half of the first X (unquestionably Swedish) as "NW European."

So it looks like it is grouping at least some of my Swedish into NW European, not terribly shocking.

Amber29
07-29-2019, 06:25 AM
Updating this, I've been working on DNA painter. As expected, one of my mom's X chromosomes (that from her dad) should be entirely from his Swedish mom, and that seems to be the case.

However, my own X (from my mom) seems to get the first quarter from my maternal grandmother, and then the rest largely from her dad. But at 23andMe one of my X chromosomes shows the first half (bit more, really) and not the second as Scandinavian. That necessarily includes either the part from my dad or from my mom's mom, both of which are not Scandinavian but most likely English. 23andMe shows 100% of my other X as English and Irish (likely true for my dad's) and then the second half of the first X (unquestionably Swedish) as "NW European."

So it looks like it is grouping at least some of my Swedish into NW European, not terribly shocking.

Atleast you were able to work it out. I am still not sure if they carry the south asian or if we carry the northen and southern european. Lol ill find out once my grandparents test through FTDNA and see where it matches closely. Mine shows as overall full south asian on X..

Marv
11-03-2019, 03:24 AM
My one X chromosome is mostly Nigerian, Broadly West African, and then some Broadly Northwest European

My AC percentages for these three:
Nigerian 35.5%
Broadly West African 10.8%
Broadly Northwest European 4.5%

In total, those three ancestries make up 50.8% of my autosomal DNA. Is this a coincidence(being just over 50% of one parent) or does it correlates to all of what I inherited from my mother? I haven't tested either of my parents, but being male I assume that I can get an idea of what I inherited from which parent by simply looking at what ancestries contributed to my X chromosome. I know that my great-grandmother(my mom's maternal grandmother) was of visibly mixed black/white admixture, so the broadly Northwest European could have mostly come from that side.