DNA Triangulation
By Kitty Cooper
Blogger
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1452422/Triangle2.gif)
blog. kittycooper. com
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1454805/OneChromosomeMap.gif)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/2208913/IBD.gif)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1454832/ISOGGwiki.png)
ISOGG wiki entry for Triangulation
Triangulation
- When three people all match each other at the same autosomal DNA location we call it Triangulation.
- From ISOGG: "If you have at least three people with a common ancestor matching on the same segment then you can infer that the segment came from that ancestor. "
- Inversely, if three people all match each other on the same segment then you can infer they have a common ancestor.
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1452463/Shared-cM-Relationship-Tree.jpg)
Blaine Bettinger's new DNA relatedness chart, from his site http://www.thegeneticgenealogist.com/
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1452463/Shared-cM-Relationship-Tree.jpg)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/2207845/WOLDchart.png)
George
Anna
Anton
Anna
Henry
(me)
There was a thin paper trail suggesting Kristine was our cousin via George Wald, possible son of Charlie Wold ... so I got a number of WOLD cousins to test their DNA to see if that was so
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1576655/WaldVwold3.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1576656/WaldVwoldXcl.png)
KRISTINE v my cousins
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1576685/JohnVmike.png)
Kristine compared to Mike and John on chromosome 11
John
versus
Mike
Chr 11
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1576691/JohnVmikeXcl.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1576692/JohnVmikeGMs.png)
Kristine compared to John, George and Henry
John versus 2nd cousins
George (PG) and Henry
Chr 14
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1576709/JohnVgeorgeXcl.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/3891107/JohnGeorgeHenry.png)
(George)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1455632/MikeKaty16.png)
Kristine compared to Mike and Katy
Mike
versus
Katy
Chr 16
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1576737/MikeVkatyXcl.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1576747/MikeVkatyGM.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1562452/KrsitineRelated.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/3476396/DNAtree3.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/3476401/MMvsKristine.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/3476432/1c2R.png)
The total number of cMs seemed low until I realized that she was from a different wife of Charley so a HALF 1C2R
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/3476424/WoldMapS.png)
Only one of the five segments MM shares with Kristine are in the same location as the other cousins, the one on chr 11, does it triangulate?
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/3477111/TG.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1578952/LuAnnDNArel.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1581942/LuAnnTableComp2.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1455906/LuAnnXcel1.png)
Another way to triangulate is to use other known relatives. Sometimes my brother and I got opposite segments from our Dad
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1455906/LuAnnXcel1.png)
These are my dad's matches: Everyone marked M for maternal matches my brother Ship, but the P for paternal matches me
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1455877/LuAnn23andme.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1578546/LuAnnXcel2.png)
M
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1579101/GunnarMatch.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1456093/GunnarFTW.png)
Gunnar versus my Dad
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1456093/GunnarFTW.png)
Gunnar versus my Dad
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1456116/GunnarVship2.png)
Gunnar versus my brother
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1456017/GunnarICW.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1456153/ICWgunnar.png)
Top matches Dad has in common with Gunnar
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1456191/GunnarKittyCpr.png)
Gunnar versus Kitty, no match on 2, match on 20
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1455906/LuAnnXcel1.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1456204/Matrix.png)
Dad's Matrix Matches
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/3477134/GetCBRfile.png)
How to get a Chromosome Browser Results (CBR) file
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/3477141/DMTprocessing.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/3477142/DMTresults.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/3477144/DMTcsv.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/3477144/DMTcsv.png)
DMT output as a CSV
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1456859/Tier1.png)
Automated Triangulation Tool at GEDmatch.com
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1456866/TriFormGedmatch2.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1456825/GEDmatchChr2Tri.png)
GEDmatch triangulation sorted by chromosome location
Gedmatch Triangulation for Dad sorted by Match Name
Cousin Katy
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/1464781/GEDmatchTriKaty4.png)
Gedmatch Triangulation for Dad cut and pasted to a spreadsheet then sorted by chromosome and start
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/3891162/DadTri.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/2693263/Compare23andMeSmll.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/2693265/DNA-RelativesCompare.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/4985687/MyHmatches.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/4985688/TriIcon.png)
![](https://s3.amazonaws.com/media-p.slid.es/uploads/176516/images/4985690/TirImage.png)
Blog.KittyCooper.com
DNA Triangulation -2018
By Kitty Cooper
DNA Triangulation -2018
How to use triangulation to confirm DNA relatives
- 4,463