Search Results for: parents related

How Related Are Ashkenazim?

Eight of the ten fully Jewish kits I have access to showed related parents in the “Are Your Parents Related” (AYPR) tool on GEDmatch. I am wondering if this level of relatedness (about a 4th cousin) is generally true among Ashkenazim and other endogamous populations. Or perhaps the GEDmatch parameters need some tweaking?

Sample related segment from a Jewish kit in AYPR

Also a number of married jewish couples I know have discovered that they share a DNA segment. Personally I share 11 cM on the X with my late husband even though I have only one Jewish grandparent. Most testing companies show me as about 30% Jewish.

I can understand that when people live in the same general area for generations, one could easily marry 3rd and 4th cousins. I also know that in the past, cousin marriages were not uncommon among Jews.

I invite all tested fully Jewish people to run that free tool at GEDmatch and then fill out my form on the next page. Please fill it out even when they are not showing as related to help with my statistics.

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All My GEDmatch Articles

Apr7

GEDmatch is one of my favorite sets of genetic genealogy tools but it can be hard to get started with. I have done many presentations over the years attempting to help people master the basics there, most recently for Family Tree University (click here). Plus I wrote a GEDmatch Basics article for their magazine (click here) which explains all the column headings on the one-to-many report. [UPDATE 15 Apr 2024: Click here for the interview I did for the FTU podcast.]

Over the past 12 years I have written many posts about GEDmatch, most of which are still useful. So I decided to make a new tag – GEDmatch tools – which brings up just my posts that explain a specific tool. Now I can see which tools I still need to write about!

Here is the list of my articles in reverse chronological order (click any title to go to that post):

Important Changes at GEDmatch

Dec17

If you have not logged into GEDmatch recently, please do so and either accept the new terms and conditions or don’t. Unless you are clearly USA based*, your kits will not be visible to your relatives any more unless you accept. I have linked to numerous other blogs at the end of this article to help you make your choice. I recommend reading either the one from Roberta Estes or EU users, the one from Debbie Kennett. Both look carefully at the new terms and conditions which are not very different from before.

Frankly, I was surprised by the panic expressed last week by some in the genetic genealogy world on FaceBook due to the sale of our beloved GEDmatch DNA tools site to a forensic science company. Personally, I hate knee jerk reactions so I did some research into this company, Verogen, as well as communicated extensively with Curtis Rodgers, one of the GEDmatch founders, and Kim Mohr, a spokesperson for Verogen.

To remind you all, GEDmatch is the best place to compare DNA tests done at different companies to each other or just to see the actual chromosome locations shared by two Ancestry testers. While both Family Tree DNA (ftDNA) and MyHeritage accept uploads of tests from other companies so you can compare on those sites, neither has the extensive tools of GEDmatch. FtDNA compares down to very small segments which can be useful in a family project but leads to inaccurate relationship estimates. MyHeritage does not show the X chromosome and neither company shows the fully identical segments (FIRs) that full siblings will have, which can be so helpful (click here).

The DNA Applications menu at GEDmatch

GEDmatch has many useful additional tools, such as “People who match both or 1 of 2 kits ,” an “Are your parents related?” test, the ability to see who matches you on a specific segment, being able to check for full siblings rather than half, and automated triangulation, to name a few of my favorites (click those words to go to that post when I did one or click here for my more general GEDmatch articles). Plus it has GEDCOM comparison utilities. Compare yours to all the ones in the database or to just one other.

GEDmatch became a center of controversy when it was discovered that genetic genealogist Barbara Rae-Venter, working with law enforcement (LE). had solved the Golden State Killer case (click here) using that site. Since that time, there have been more controversies around law enforcement’s use of the site and many overblown scare articles in the press. Personally if my DNA outs a distant cousin who is a murderer or rapist, that’s fine with me. Genetic genealogy techniques are used as a tip; no one is arrested without getting their DNA from discarded materials and seeing if it is a match to the crime scene. I know some people are afraid of the possibility of false arrests, but that just does not happen with these modern techniques. You can, as before, choose to opt out of allowing LE to see your results on GEDmatch when looking for cousin matches to the dna of the perp or the unidentified victim.

In recent months, there have been more problems, news stories and controversies, including a Florida search warrant being granted. One has to feel for the two retired hobbyists who founded GEDmatch to help in their research and ultimately help us all, keeping most of the features free. Clearly getting the site owned and managed by a more professional group would be of great advantage to the users. Curtis spent several months looking for the right partner that would respect the original misson of GEDmatch and yet deal appropriately with LE, the EU, and security issues. He and the programmers, the two Johns, will continue to work on the site as consultants.

So who or what is Verogen? Two years ago this company was spun off from Illumina (the maker of the chips and machines that all the consumer oriented DNA testing companies use to sequence your DNA). It has 50 plus employees and plans to continue growing. Their office is in a small office park near UCSD here in San Diego. Continue reading →

Help Collect DNA Statistics

Aug24

Blaine at the Gorge Wildlife Park, Cudlee Creek, South Australia (used with his permission)

Many families have grandparents or great grandparents who are first or second cousins. Within family marriages did not used to be as unusual as they are today. However for those of us who work with DNA, the extra relatedness adds confusion to interpreting the comparisons of their descendants. Plus there are people whose parents are related. It would be nice to have some charts showing the expected DNA amounts in these more unusual relationships.

Some of you are familiar with the statistics Blaine Bettinger has collected for more ordinary relationships. (Click here to contribute your numbers there) The calculator at DNApainter, which we all use to check the possibilites for an unknown DNA relationship, is based on his research and the statistical work of Andrew Millard and Leah Larkin.

Now Blaine is collecting the data for these more unusual relationships. So any of you who have DNA results from known double cousins or other family members whose descriptions fit, please click that image below to go to the form where you can add your numbers to his new project.

There are more places to contribute your numbers
Continue reading →

Basics: GEDmatch reinvented part 1

Feb11

UPDATE 18-AUG-2019: Since the GEDmatch site and GENESIS are one and the same now I have updated this post to say GEDmatch rather than GENESIS

GEDmatch.com is a free 3rd party site of tools where you can upload your DNA test results and compare them with those from people who have tested at other companies. It is the new version of GEDmatch.com that can compare the data from many more companies than the original. Click here for my previous post written for GEDmatch users moving to GENESIS. Today’s article is to introduce the new version of the GEDMATCH basics to the new tester.

GENESIS Home page for my cousin who has only 2 kits migrated and is not a Tier 1 member

One problem for many users is that this site is not intuitive. GEDMATCH does not hold your hand and does not build your tree for you. You have to learn how to use the tools there to the best advantage for your own research. I have many posts on this blog for GEDmatch, . UPDATE 17 FEB 2019: Click here for the slides from my presentation about the basics of using this site from Saturday Feb 16, 2019, in Carlsbad for the North County DNA Interest Group (DIG).

To get started at GEDMATCH, you have to be registered as a user. Your login will be your email address with a password you create. Some people prefer to use an email which they have created just for genealogical research. Easy to do at gmail, hotmail, or yahoo, among others and it is a way to create some privacy. Note that GEDmatch is careful to warn you when you register that their site can be used by law enforcement to try to identify violent offenders and victims. Click here to understand how your DNA can out a distant cousin who is a criminal.

Before you can use GEDMATCH to explore your test results, you have to download your DNA data from your testing company. Click here for the help page that GEDmatch provides on how to download your DNA. The file of your test results is quite large (about 700,000 lines of data) and zipped. DO NOT UNZIP it.

To upload your results to GEDMATCH you log in and then click on Generic Uploads (23andme, FTDNA, AncestryDNA, most others) in the right hand column under Upload your DNA files. That takes you to a form to fill out before doing the upload. You have to enter the name your kit was registered under, but you can choose to use a pseudonym to appear on GEDMATCH. Put it in the box for alias on this form. For example, all my cousins are called Kittys#CuzNN where the number sign is 1st, 2nd, or 3rd, and NN is their initials so that I know who they are! You have to change the No to a Yes after “You authorize this data to be made available for comparisons in the GEDmatch public database” if you want your results to be visible to your matches. If you want to stay private, then leave it as is for now, but change it after it is uploaded to “Research” so you can use all the tools on the site but stay invisible. Once your or your cousin’s file is uploaded, you are assigned a kit id (2 letters plus several digits) which will also always show on your home page when you log in. You need a kit id to use the tools. You can upload multiple tests and manage them all from this one user.

You can make edits to any kit you own by clicking the pencil icon next to it on the left side of your home page. Click here for my presentation slide that shows you that edit screen and where to change the privacy to public or research or private.

It usually takes a day or two to fully process your kit so that you can run the most important tool: the one-to-many. That is the tool that lists your DNA relatives in the GEDmatch database. While you wait you can experiment with the ethnicity tools (called admix here) covered in my Gedmatch basics post and in detail in these slides (click here).

If some cousin, like me, asked you to upload and gave you their kit number, you can do a one to one compare with that kit before your kit is fully ready for the other tools. Click here for the slide that shows the form to make that comparison. There are slides following that one which have some examples. You can use all the defaults when you fill out the form with one exception: you may prefer to check the prevent hard breaks box at the bottom. That is particularly recommended for an X one to one. Personally I prefer to look at the image only comparison first, then I click back and select position only to get the numbers for each segment to put in my master spreadsheet.

Once you see a blue check mark on the line with your kit number on your home page (as in image above), you can run the one to many tool. That looks at all the other kits in the database to find people whose DNA matches yours. The more cMs you share, the closer the match.