Tag Archive | GEDmatch Tools

More Clustering Tools!

May7

There are many new ways to make those beautiful cluster diagrams of how your DNA relatives are related to each other. Both MyHeritage and Gedmatch (tier 1) now have clustering tools (Thank you Evert-Jan Blom). These charts give you an easy way to see your family groupings and can help you figure out a new match since each cluster typically represents a common ancestral couple. Click here for my previous posts on clustering which is based on the Leeds method.

My Dads Clusters at Gedmatch GENESIS

The GEDmatch cluster diagram shown above includes the total cM each match shares with you as well as their name and kit number. Click on the “i” in a circle for a pop up box with the user information which includes an email address and whether a GEDmatch tree is linked to this kit. Any of the colored boxes on the graph can be clicked to open a window for a one to one comparison between those two people. Plus you can check the boxes in the select column for any number of matches and then submit them to the multi kit analysis using the orange “Submit to Multi Kit Analysis” button above the name column on the left. To get this clustering tool all you need is a Tier 1 membership and a kit number. It is listed at the bottom of the Tier 1 tools. Personally I like to raise the thresholds to a top 200 and a minimum of 20, but try the defaults first and see what is best for you.

One of the nice things about the cluster output from Genetic Affairs is that it lists all the cluster members in groups below the graph with the number of people in each tree (clickable) and any notes you made on the Ancestry profile. The MyHeritage version also has those cluster lists with your notes and the tree sizes; and of course they are clickable to the match (which may even have a theory of family relativity for you!) and the match’s tree. The down side is that you cannot select the parameters for the clustering yourself, they are preset. Possibly only power users care about that!

Extract from my list of matches in each cluster at MyHeritage

An exciting new feature for those looking for one unknown parent or grandparent is the ability to cluster just your starred Ancestry matches when using the clustering tool at Genetic Affairs.  Click here for my previous post about that tool. There now is a checkbox on the page where you select your parameters for getting a cluster analysis.

Newat Genetic Affairs is the checkbox for only starred matches when starting a cluster analysis

It is a common practice to star (mark as favorites) the matches that seem to be from the family of an unknown parent or grandparent at Ancestry. Usually these are determined by looking at who matches or doesn’t match a close relative like a half sibling or else by eliminating matches from the known side. Sometimes you can use ethnicity. I am currently helping someone where the known side is Jewish and the unknown side is Italian and those are easy to separate.

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Make a combined DNA kit for yourself

Apr7

Have you ever wanted to make a kit combining all your DNA tests at the different companies so as to get the most SNPs for comparisons? Well GEDmatch provides that for paid members. So of course I made one of these superkits for myself! I combined my LivingDNA with my V3 23andme and my current Ancestry kit. Now to investigate what I have gained from this.

The first thing I did was compare this new kit to my recent Ancestry kit. All looked fine. It has the expected small differences, many of which disappeared (including the black lines) when I checked the prevent hard breaks box on the form. The older 23andme kit comparison had more black spots and mismatches.

My next thought about my new superkit was that I might get a better comparison to cousins who tested more recently at 23andme but none of them have uploaded to GENESIS yet. So I checked how my comparison to an Ancestry tester, my second cousin once removed Jeanie, looked. The superkit gets the same result as my recent Ancestry kit. When I compared her to my 23andme kit and my Living DNA kit however, there were small differences.

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New Compact Chromosome Browser on GEDmatch’s GENESIS

Aug10

Today GEDmatch launched a version of my segment mapper which is integrated with their database. It can be used as a way to easily visualize multiple matches on GENESIS. This first version shows how everyone compares to the first person on the list, like the current 2D chromosome browser but more compact. Also each color is a person.

My Munson cousins in my new compact segment mapper at Genesis

Above is the screenshot of my Munson cousins which even shows one of the boxes that appears when the cursor is placed on a segment. Click on this image to see a copy of the html version (edited for privacy) where you can put your cursor on any segment to see the details. (N.B. when you put your cursor on a segment and the information pops up via javascript that is called a mouse over in geek speak. )

One way to get a display like this at Genesis is to check the boxes (tier 1 only) next to your best matches in the one-to-many (up to 40 of them) and then click the button “Visualization” at the top of the page. Another way to get there is to use the Tier 1 tool “MultiKit Analysis” and select the kits you want to look at. Remember the first kit listed is the one that all the others will be compared to.

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When the DNA says your parents are related

Jul25

One of the first things I do when helping someone with their DNA results is to check if their parents are related. This can explain unusual patterns of matches, for example, all seemingly from one side.

GEDmatch.com has a nice tool called “Are Your Parents Related” (AYPR) in the”Analyze Your Data” blue panel (middle right of page) which looks for places in the specified kit where the DNA is identical on both chromosome pairs, maternal and paternal. This happens when you inherit the same segment of DNA from each parent because they are related. We call this a homozygous run which is a fancy way of saying a stretch of identical DNA on both sides.

CeCe Moore specializes in helping people who make this discovery. Click here for the informational brochure she helped Brianne Kirkpatrick, genetic counselor, create. It includes where to get emotional support.

My goal is to help you figure out what the DNA means yourself. Can you deduce what the relationship of those parents is? Well a very simple rule of thumb is to multiply the shared DNA from AYPR tool by four and look up that new total at the DNA painter calculator for the possibilities. Then do further family DNA testing to confirm.

Why does this work? Let’s look at the numbers. Suppose your parents share 25% of their DNA. They will pass about half of that to you, so 12.5%. However only about half of that will be the same DNA so it will show up as about 6.25% on the AYPR tool.

Look at the image. The total is 215.3 when you multiply by 4 you get 861.2. You might look that up before you read on …

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Family Trees are now linked to from the GEDmatch Tier 1 One-to-Many

Mar24

The new Tier 1 one-to-many at GEDmatch includes a link to your match’s family tree when that is available. Clicking the word GED next to that kit’s email address takes you to the tree your match has uploaded to GEDmatch. The word WIKI links to the compact tree view at WikiTree.

GEDmatch GEDCOM link

Clicking on the GED for a match takes you to the profile of the individual in the linked tree at GEDmatch.

Here is what you would see if you clicked on the GED next to my Dad’s name. Note the words “GEDmatch Ref: “ followed by a long number. That number is the id of this GEDCOM which you can use to compare to your own GEDCOM in the “2 GEDCOMs “ function on your home page.

Of course, I immediately click on the pedigree button in the little menu at the top of this individual page and then look through the pedigree on the next page for familiar names and places. Here is what the top half of my Dad’s tree looks like at GEDmatch. Note the default number of generations shown is 5. You can change that to a larger number (I often go to 8) and then click submit to see more generations.

WIKI link

Clicking on WIKI next to a match in the Tier 1 One-to-Many listing takes you to that match’s compact pedigree at the collaborative world tree WikiTree. This is automated and the connection to Wikitree happens because a member of that site has added a GEDmatch kit number to a profile there. Here is the top piece of what you see when you click on my WIKI.

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