Go Back   Family Tree DNA Forums > The X-Chromosome > X-DNA Advanced

X-DNA Advanced Advanced topics about X-Chromosome matching and anthropologic blocks based on SNPs and/or STRs.

Reply
 
Thread Tools Display Modes
  #11  
Old 17th August 2017, 02:00 PM
ech124 ech124 is offline
FTDNA Customer
 
Join Date: Jul 2011
Posts: 220
Within the context of FTDNA, X-DNA is not treated like the other chromosomes. I don't know how ancestry.com looks at it, but they do not have a chromosome browser so that is a big disadvantage when seeking DNA proof.

Here is the FAQ here, so read it very carefully:


https://www.familytreedna.com/learn/...-test-results/

If you still want to pursue X-DNA as your primary strategy, feel free, but my suggestion is that triangulation is a better choice. That is just my opinion based on my personal experiences. If you do eventually achieve success, please let us know the steps that worked for you.

Last edited by ech124; 17th August 2017 at 02:04 PM.
Reply With Quote
  #12  
Old 17th August 2017, 02:21 PM
alphavisions alphavisions is offline
FTDNA Customer
 
Join Date: Jul 2017
Posts: 10
Quote:
Originally Posted by ech124 View Post
Within the context of FTDNA, X-DNA is not treated like the other chromosomes. I don't know how ancestry.com looks at it, but they do not have a chromosome browser so that is a big disadvantage when seeking DNA proof.

Here is the FAQ here, so read it very carefully:


https://www.familytreedna.com/learn/...-test-results/

If you still want to pursue X-DNA as your primary strategy, feel free, but my suggestion is that triangulation is a better choice. That is just my opinion based on my personal experiences. If you do eventually achieve success, please let us know the steps that worked for you.
Yes, I'm very familiar with the X inheritance pattern, which I'm using in my strategy. I had consulted a FTDNA project admin on my strategy and he thought there was validity to it...(ruling out the X-matches) but that DNA acts strangely sometimes...as we can see in the ancestry.com results I posted.

To get back on track, I think there is validity in the my strategy, and hoping to get feedback from people who are open to the strategy, may want to test it, etc. Thanks for you input.
Reply With Quote
  #13  
Old 17th August 2017, 04:21 PM
ltd-jean-pull ltd-jean-pull is offline
FTDNA Customer
 
Join Date: Jun 2016
Posts: 500
I may not be understanding what you are trying to do.

A distant male relative of mine shares no X-DNA with his maternal grandmother. He received his maternal grandfather's X-chromosome.

Using your rationale if he wasn't an X-match to your mother you would be thinking he can't be related via any line that contributed X-DNA, whereas it is quite possible the connection is via his maternal grandmother.
Reply With Quote
  #14  
Old 17th August 2017, 07:01 PM
John McCoy John McCoy is offline
FTDNA Customer
 
Join Date: Nov 2013
Posts: 712
Since it is indeed possible for a person to inherit a non-recombinant X chromosome from a female (and for a sibling to inherit the other homologous X chromosome!), the lack of X matches is not strong evidence for or against a particular relationship. Rather, the existence of an X match IS evidence of a relationship that follows the pattern of inheritance of the X chromosome.

The lack of an X match may tip the odds, but I don't regard that as proof of anything.
Reply With Quote
  #15  
Old 17th August 2017, 07:35 PM
prairielad prairielad is offline
FTDNA Customer
 
Join Date: Feb 2011
Location: Canada
Posts: 2,029
Quote:
Originally Posted by ltd-jean-pull View Post
I may not be understanding what you are trying to do.

A distant male relative of mine shares no X-DNA with his maternal grandmother. He received his maternal grandfather's X-chromosome.

Using your rationale if he wasn't an X-match to your mother you would be thinking he can't be related via any line that contributed X-DNA, whereas it is quite possible the connection is via his maternal grandmother.
Two of my sisters do not match my maternal Grandfather on X, they match my maternal Grandmother along the full length of X (they received my mothers full maternal X only)

They show as full base pair matching along the entire X chromosome at Gedmatch when comparing them

So No (to alphavisions), not matching does not mean anything other then X can not be used as an aid in determining.
Even many of the matches at FTDNA which are deemed X matches will have a high chance of being false depending on the size of segment you are looking at (segments under 7cM)
Attached Images
File Type: png sisters.png (54.6 KB, 3 views)
Reply With Quote
  #16  
Old 17th August 2017, 07:42 PM
prairielad prairielad is offline
FTDNA Customer
 
Join Date: Feb 2011
Location: Canada
Posts: 2,029
My third sister to same Grandparents. All sisters are full siblings.

All follow the X inheritance path to inherit XDNA from maternal Grandfather, but only 1 of the 3 did.
Attached Images
File Type: png sisters2.png (35.2 KB, 5 views)
Reply With Quote
  #17  
Old 18th August 2017, 05:05 AM
alphavisions alphavisions is offline
FTDNA Customer
 
Join Date: Jul 2017
Posts: 10
Quote:
Originally Posted by ltd-jean-pull View Post
I may not be understanding what you are trying to do.

A distant male relative of mine shares no X-DNA with his maternal grandmother. He received his maternal grandfather's X-chromosome.

Using your rationale if he wasn't an X-match to your mother you would be thinking he can't be related via any line that contributed X-DNA, whereas it is quite possible the connection is via his maternal grandmother.
Can you explain further why you think it's quite possible? Thanks!
Reply With Quote
  #18  
Old 18th August 2017, 05:08 AM
alphavisions alphavisions is offline
FTDNA Customer
 
Join Date: Jul 2017
Posts: 10
Quote:
Originally Posted by John McCoy View Post
Since it is indeed possible for a person to inherit a non-recombinant X chromosome from a female (and for a sibling to inherit the other homologous X chromosome!), the lack of X matches is not strong evidence for or against a particular relationship. Rather, the existence of an X match IS evidence of a relationship that follows the pattern of inheritance of the X chromosome.

The lack of an X match may tip the odds, but I don't regard that as proof of anything.
I know a lot of people have this same opinion, but if you use logic, pool A has Xmatches and therefore, the rest is pool B - nonXmatches. Thus, it follows that if you are not in pool A, you must be in pool B. So I think there is something here to investigate. Unless you can show us why it is not strong evidence? do you have an example?
Reply With Quote
  #19  
Old 18th August 2017, 05:12 AM
alphavisions alphavisions is offline
FTDNA Customer
 
Join Date: Jul 2017
Posts: 10
Quote:
Originally Posted by prairielad View Post
My third sister to same Grandparents. All sisters are full siblings.

All follow the X inheritance path to inherit XDNA from maternal Grandfather, but only 1 of the 3 did.
I'm not sure I follow your logic. your sisters could inherit their x from either your maternal or paternal grandparents and they did... That follows exactly the x inheritance paths. So why would this disprove a nonXmatch?
Reply With Quote
  #20  
Old 18th August 2017, 10:47 AM
MMaddi MMaddi is offline
yDNA: R-CTS2509; mtDNA: T2e
 
Join Date: Jul 2005
Location: Houston, TX
Posts: 3,391
Quote:
Originally Posted by alphavisions View Post
Can you explain further why you think it's quite possible? Thanks!
Because it actually happened in the real life example that ltd-jean-pull presented. And it may happen in your case as well, which is why the assumption of no matching x segments may cause you to rule out a line in which the common ancestors actually may be found.
Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Why can't I find a MRCA ? formax Adoptees Forum 12 29th April 2017 09:32 PM
Strategy to find free articles on human mtDNA & Y-chr. DNA PNGarrison Scientific Papers 2 17th January 2015 01:49 PM
46 marker y-DNA match but MRCA way off MastoDon DNA and Genealogy for Beginners 13 18th May 2011 07:16 AM
Amazing! autosomal match leads to paper trail MRCA... dwight DNA and Genealogy for Beginners 4 17th February 2011 12:26 AM
35/37 match - 10 generations+ to MRCA... NormanGalway Paternal Lineage (Y-DNA STR) Advanced 18 8th July 2006 10:51 PM


All times are GMT -5. The time now is 01:27 PM.


Family Tree DNA - World Headquarters

1445 North Loop West, Suite 820
Houston, Texas 77008, USA

Phone: (713) 868-1438 | Fax: (832) 201-7147
Copyright 2001-2010 Genealogy by Genetics, Ltd.
Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.