DNA Day at GEDmatch
By Kitty Munson Cooper
Blogging at blog.kittycooper.com
Or How I Use GEDmatch
to Solve Mysteries
All my slides are always online at
I started using GEDmatch because I had cousins who had tested at different sites and I wanted to compare them
Then I discovered that not only could I compare them at GEDmatch but it had some unique tools
Why is GEDmatch is still the best place to compare your kit to DNA tests from Ancestry or relatives tested at different companies?
- MyHeritage does not show the X
- Family Tree DNA does not show comparisons of third parties to each other nor triangulations
- Neither shows fully identical regions (FIRs)
- and there are way more segment level tools at GEDmatch
To the left are a few of the many free tools
Not all sites let you get the segment data from an Autosomal DNA comparison like GEDmatch does
Unique to GEDmatch:
Are Your Parents Related
Comparison of the X
3. One-to-one Autosomal DNA Comparison (also check FIRs)
5. Run the People who match both kits, or 1 of 2 kits
4. Do the One-to-One X Comparison
1. Convince them to upload to GEDmatch
and send me the kit number
My CURRENT APPROACH when I get a new match at one of the testing sites is ...
a. Run the Kit Diagnostic Utility on their kit
2. Check for any anomolies in their kit
b. Run "Are your parents related" (AYPR) tool on their kit
I had a new match at Ancestry, Beryl, about a 3rd cousin
she did not know who her father was
clearly he was my relative as I did not match anyone
on her known mother's side
1. I asked Beryl to upload to GEDmatch
and send me the kit number. I told her
to go to GEDmatch, make a username
and password, then go to the upload
page which has instructions:
https://app.gedmatch.com/dnaupload/
Next I ran the "Are your parents related" tool
Unless you are from an endogamous population or know your parents are cousins this will likely be negative
Beryl's result was negative
Example from an endogamous population where parents often turn up to be related
I am collecting these results for people with Jewish ancestry
https://blog.kittycooper.com/2023/02/how-related-are-ashkenazim/
The X is often important for figuring out relationships since men have only one X from their mother.
Thus sisters who share a Dad will share a full X, see
http://blog.kittycooper.com/2014/03/how-can-the-x-chromosome-help-with-maternal-versus-paternal/
Two HALF sisters
Two full sisters
Beryl shared no X with me.
One-to-one Autosomal DNA Comparison
Check display only Matching Chromosomes
One-to-one Autosomal DNA Comparison
Displaying only Matching Chromosomes
One-to-one Autosomal DNA Comparison
Displaying only Matching Chromosomes
One-to-one Autosomal DNA Comparison
Numbers only versus my Dad
One-to-one Autosomal DNA Comparison
Displaying only Matching Chromosomes
One-to-one Autosomal DNA Comparison
What about FIRs (Fully Identical Regions)?
FIRs occur when people are related on both sides.
For example, full siblings or cousins where 2 sisters
married 2 brothers.
Beryl had no FIRs with my Dad or me.
Here is a part of the comparison of 2 full siblings.
Green areas are FIRs
Text
5. The People who match both kits, or 1 of 2 kits
in the form put the other kit first
Beryl had a first cousin match to a known 3rd cousin of mine!
Beryl me
Now all I had to do was email my 3rd cousin Diane and we were able to figure it out
Diane's MUNSON mother had two brothers, only one of whom fit the facts
Beryl added her dad to her tree at Ancestry and soon thrulines connected us
Because Beryl was a fairly close relative, the one-to-many function would have also figured out which family she belonged to
This is her one to many with one tag group selected
The one to many is the work horse of relative searching
In order to get the colors for tag groups click the circle next to One
on the form for the one to many
Close up: Review the headings. Everything blue is clickable
Click the largest segment under autosomal to get the one to one comparison for that match, same for X
click the kit number to get the One to Many for that kit
Close up: note the testing company and how many SNPs are in common between the kits and mitoYDNA has been linked to a haplogroup
Click the largest segment under autosomal to get the one to one comparison for that match, same for X, Match gets kits that match both
Tag groups make the one to many more useful, see
To set up or edit your tag groups click on the
MANAGE next to your profile summary
The next page has a set of tabbed headings; click on Tag Group Management
Give the group a name in description and a color by selecting one from the color chart
The shared option is not yet implemented but you can transfer the group to another account
Mapping which segment comes from which Ancestor
Currently GEDmatch is the only site which lets you download all the matching segments that you have with your DNA relatives via the Segment Search
Put in your kit number and increase the number of matches, otherwise the defaults are fine except unclick the box Show graphic bar for Chromosome?:
When the tool completes, there is a button to download the CSV
This CSV can be manipulated in Excel and used to track which segment comes from which ancestor
My Dad's Map of which segment comes from which Ancestor
I have added columns for side, name, source, and ancestor plus email address and who else matches (not visible here)
Vien, a Cambodian, knew his 4th grandfather
was a Norwegian sailor.
He has a single segment match with my Dad that triangulates with many cousins descended from my ancestors on Ve (Wee) farm in Etne, Hordaland, Norway
On the spreadsheet of all my Dad's segments, I assign them to specific ancestors when multiple cousins match there.
This is called TRIANGULATION
2nd and 3rd cousins are very useful for this process
A Norwegian DNA match to Dad with a deep family tree found that he is my 12th cousin twice removed
His single segment match to my Dad and my brother is in a pile up area with about 100 or so matches on the various sites
Actually GENI.com figured it out the relationship for us.
So now I wonder if those many other matches on this 12cM pile up area are also descended from this ancestor
Could I investigate using thegranularity on
Segment Searches (Tier 1) ?
OOPs, I see cousins on both Dad's paternal and maternal side. How might I ensure that those overlapping segments triangulate?
This way found 64 segments. My brother has this same pile up ....
A phased kit of the DNA my brother got from my father can be used!
Much better, only 54 and only Dad's maternal cousins now
Another way to use the segment search is when you have a family health issue that is traced to a specific gene
I did this for my late husband's family
