What's hidden in your chromosomes?

DNA & Genealogy

Tips for using GEDmatch

Those new to DNA testing for genealogy will soon become aware of GEDmatch.  Common questions asked in genetic genealogy groups once a member receives their autosomal DNA results include: "How do I upload my raw data to GEDmatch?", "How do I use GEDmatch once I have uploaded?", and "What does it all mean?".

The tips below are intended to help beginners get started with the most common GEDmatch reports & tools, and give them confidence to experiment with the more detailed utilities.

 

What is GEDmatch?

GEDmatch.com is a free, volunteer-run website for people who have already tested their autosomal DNA for genealogical purposes at  AncestryDNA23andMe, Family Tree DNA, MyHeritage DNA, or tested for health purposes at WeGene, GenetiConcept or Genes for Good.

Testers download a copy of their autosomal raw DNA data file from their own testing company online account, and then upload this file to GEDmatch where it is processed and added to a large database.

 

GEDmatch offers:

  • DNA matching to relatives who have tested at other companies
  • Tools to compare and analyse DNA shared with others
  • Admixture reports (ie. ethnicity/heritage predictions)
  • Extras: Archaic DNA, Eye Colour, Parent Relatedness, Kit Diagnostics, Tier 1 options

 

GEDmatch is extremely popular, very highly regarded, and the site is often quite busy - but be patient as it is definitely worth it!

If you're not convinced you need it, refer to Jim Bartlett's list of reasons why you should upload your autosomal DNA raw data to GEDmatch.

 

Basic Education

Before starting with Gedmatch, it will make a big difference if you already understand some basics of genetic genealogy.  If you have only tested at AncestryDNA before, you may have never heard many of the common terms used (eg. cMs, SNPs, MRCA, segments, triangulation).

So once you have uploaded your data and are waiting for it to process, head over to the ISOGG Beginners' Guides to Genetic Genealogy and to my list of Genetic Genealogy Links & Resources and do a bit of preliminary learning.

Check the beginner links, glossaries, watch some introductory videos, look at some of the commonly-used charts, subscribe to popular blogs, join some Facebook groups, read about segments, matching, identical by descent, and more.  Read Jim Bartlett's blog Segmentology to learn about shared DNA segments, recombination, crossovers and triangulation.

 

First Steps

  • Register at GEDmatch.com using your email address and a password.
  • Download your autosomal DNA raw data file from your testing company.
  • Upload your autosomal DNA raw data file to GEDmatch. 

 

Tips

  • Instructions for downloading your raw data file from your testing company are available in Gedmatch, by clicking on the Generic Upload FAST link in the blue panel near the top right of the page (or the 23andMe fast & easy link if you are going to upload from 23andMe):

    Generic Upload FAST link

    Links to download and upload instructions for each testing company are at the top of the upload page:


    Gedmatch data upload instructions



  • When downloading your raw data file from your DNA testing company account, leave it zipped, don't try to open it as it contains 700,000 lines of numbers and letters; Some browsers unzip downloaded files by default (eg. Safari on Macs), in which case you'll need to edit the settings (refer to instructions in the GEDmatch Upload link); the autosomal DNA file will be about 6MB in size.  WeGene users must compress their their raw data file into a zipped file first (refer to instructions on GEDmatch's WeGene Upload link).
  • You can upload multiple DNA kits to your one GEDmatch account.

 

Kit Numbers

Once your kit has successfully been uploaded to GEDmatch, the tester's kit number, name and alias will appear in the Your DNA Resources panel on the left side of your GEDmatch dashboard (home page).

Your GEDmatch kit number will be a letter followed by a randomly-generated kit number.

  • AncestryDNA kit numbers start with 'A'
  • 23andMe kit numbers start with 'M'
  • Family Tree DNA kit numbers start with 'T'
  • MyHeritageDNA kit numbers start with 'H'
  • WeGene kit numbers start with 'W'
  • GenetiConcept kit numbers start with 'E'
  • Genes for Good kit numbers start with 'G'
  • Generic or custom kits start with 'Z'

While your kit is still being processed, it will be preceded by two asterisks (**), at which stage you can use only a limited selection of tools.  Expect the processing to take a day or two, but occasionally it can be ready within just a few hours.

 

GEDmatch Dashboard

Below is an example of the GEDmatch dashboard (ie. main home page). 

Observe the section headings, as they will help you find everything you need.

The grey panel on the left contains information about your login, member status, links to helpful resources, your uploaded kits and Gedcom (family tree) files. 

The blue panels on the right contain upload links in the top section, and reports and tools in the lower sections (Tier 1 utilities are accessible for a month if you donate US$10).

 

GEDmatch Dashboard
 

The report you will probably be most keen to run is One-to-many matches to look for new matches, but you need to wait for processing to finish before this can be done.

While waiting for your kit to finish processing, you can use the One-to-one compare, Predict your eye colour, Are your parents related?, and some Admixture (ethnicity) reports and Archaic DNA comparisons.  You can also Search all GEDCOMs to look for names or places of interest, and through those find some kit numbers that you can try out in the One-to-many matches report.

 

Are your parents related?

For most testers this report will be unremarkable, as per the first image below.  'Are your parents related?' will reveal if the tester's parents were related in very recent generations.  Similar to regular autosomal DNA match statistics, it does not always show if your parents were related more distantly - such as 3rd, 4th cousins or further back, but will clearly show closer relationships.

If your parents shared an ancestor, and they both inherited one or more of the same segment(s) from that ancestor, and they both passed one or more of those same segments on to you, it will be highlighted in this report.

A typical result for a tester with unrelated parents will look similar to this example:

 

Gedmatch report - parents not related 

The following result is an extract from a tester whose parents were 1st cousins.

 

Gedmatch report - parents related

 

Enter your own kit number.  If your parents are or were related in very recent generations, you will see bright blue blocks (similar to above) indicating identical DNA segments of more than 7 cMs inherited by you from both of your parents.

When you run this report for your kit, you will see the colour-coded key/legend at the top of the report. 

If your parents were related, information on the total shared cMs, largest segment, and estimated number of generations to the Most Recent Common Ancestor (MRCA) will be shown at the bottom of the report, along with resources to obtain additional information or support if necessary.

 

Predict your eye colour

Run this tool on your kit number to see if it predicts your actual eye colour.  Some predictions are better than others, and 23andMe V3 data is expected to give the most accurate results. 

While logged into GEDmatch, go to the Wiki to read about the rules used, SNPs and testing company differences.

Just below the image is an accuracy feedback survey, so do submit this to GEDmatch to assist in further refinement of this tool.

 

Gedmatch Predict Eye Colour

 

Admixture utilities

GEDmatch provides 55 different Admixture calculators, accessible from two links on the dashboard - Admixture (heritage) and Admixture/Oracle with Population Search.

While logged into GEDmatch, go to the Wiki and read about the various calculators and their options and how to use them.  The Wiki also provides information on the various projects and calculator choices, and a list of reference populations.  Once you do run a report, also follow the additional resource links displayed in the report.

Produce pie charts showing ancestry estimates using different projects and reference samples:

 

Gedmatch sample Admixture pie chart 

The population search option allows you to select a calculator that contains a specific reference population by searching for a string of characters in the population name (eg. 'austral', 'british', 'swed'), or looking for available populations listed in the Wiki.

Experiment with the different projects, calculators and Oracle options, and refer to the GEDmatch Wiki for additional information including acronyms, suggestions for calculators for particular ethnic origins, links to further information, and lists of the reference populations.

As a start, if you have European origins you may like to try Eurogenes K13, for a more general overview try Dodecad World 9, MDLP K13 Ultimate or MDLP World-22, for Jewish ancestry try the Eurogenes Jtest, and for Asian origins try the HarrappaWorld project.  The number in the calculator name indicates how many reference populations are included in that calculator, so the higher the number, the more reference populations are included in the resulting table and pie chart.

 

Archaic DNA matches

Have some fun comparing your DNA with ancient samples.  Run the Archaic DNA Matches report to display your 'heat map', and see if your kit produces any almost-orange rows, and also check the red & blue heat map row at the bottom, which identifies segments that match across multiple kits.  Then run One-to-one compare reports on the individual archaic kit number samples, which are available from the left column of the heat map itself, and listed with additional details on Felix Immanuel's website.

While logged into GEDmatch, go to the Wiki for more information and links on this topic. 

Click on the image below to enlarge it in a new window.

 

Gedmatch archaic DNA matches heatmap

 

'One-to-many' matches

Once your kit has finished processing, you will want to run this most popular report to see if it identifies any new or closer matches to you, especially if you have only tested at one of the DNA testing companies for genealogy.

 

Simply enter your kit number or select it from the drop-down list (which lists your kits), leave the other values at their defaults, and click Display Results.

The default selection is Autosomal for this report, but note for later that you can also select X.

 

Gedmatch One-to-many matches report

 

Below is an example of the One-to-many matches report.  Don't be deterred by all the numbers and perceived complexity... you will understand it and get the hang of it quite quickly!

GEDmatch has compared your autosomal DNA data to every other kit in the database, and listed the top 2000 kits that share some DNA with you, with the closest matches at the top:

 

Gedmatch One-to-many results 

Familiarise yourself with the report headings while looking at your top matches:

  • Kit Nbr - the first character of the kit number indicates the testing company of the match
       eg. T = Family Tree DNA,     A = AncestryDNA,      M = 23andMe,
             H = MyHeritageDNA,      W = WeGene,             G = Genes for Good,
             E = GenetiConcept,         Z = Generic/custom/undetermined
  • Type - the chip version of the test kit (eg. V2, V3, V4 relevant re transfers to FTDNA).
  • List - click on the 'L' next to any kit to run the One-to-many matches report for that kit.
  • Select - tick the checkbox next to 2 or more kits of interest and then click on Submit (in the grey area above the report) to run a selection of cross-kit visual analysis tools (see more below).
  • Sex - gender of tester entered by user:  M=male, F=female, U=unknown; (optional, but useful for X-matches).
  • Haplogroup - mtDNA and Y-DNA haplogroups entered by the user (optional, but useful).
  • Autosomal - information on how much DNA you share on chromosomes 1 to 22 (autosomes):
    Details - click on the 'A' next to any kit to run the One-to-one comparison report.
    Total cM - is the total amount of DNA shared (cM is the measure of genetic distance, called centiMorgans) and this amount is used to estimate the possible relationship (see ISOGG chart below).
    Largest cM - is the size of the longest individual segment of DNA.
    Gen - is the estimated number of generations back to the Most Recent Common Ancestor (MRCA), eg. 4.0 gens could possibly be a 3rd cousin, 4.5 gens could be a 3rd cousin once removed.
  • X-DNA - information on how much X-DNA you share on chromosome 23.
    Details - click on the 'X' next to any kit to run the X One-to-one comparison report.
    Total cM - the total amount of X-DNA shared with your match.
    Largest cM - the size of the longest individual segment of X-DNA.
  • Name - the match's name or optional alias (eg. nickname, username, intials)
  • Email address of the match (or their kit administrator)

 

What to look for...

Top Matches

  • Check the matches at the top of the list: the number in the Gen column indicates the estimated number of generations back to the Most Recent Common Ancestor (eg. 3.5 could be a 2nd cousin once removed or a 3rd cousin); and the number in the Total cM column is the total amount of DNA shared, in centiMorgans.  Refer to the ISOGG Autosomal DNA Statistics chart below to lookup the relationship based on centiMorgans (cMs).
  • Return to GEDmatch and run this report regularly, as this is where new matches will appear as more testers upload their raw data, and there is no alert for new matches (unless a new match emails you directly).

Kit Numbers

  • Check the kit number prefixes of your closest matches to see if you have close matches at a company you haven't tested at, as it may indicate that you should test there as well.  Only a small percentage of testers from each company actually upload to GEDmatch, so you may be missing out on some better matches.
  • Look for kits from your own testing company that do not appear in your testing company's match list.  For example, you may have matches with FTDNA testers that don't appear in your Family Finder matches.  This can occur if the total shared DNA or the largest segment size is less than than the testing company's threshold.  You may also see AncestryDNA kits that don't appear in your AncestryDNA matches, as AncestryDNA uses a filter (called Timber) which may remove some matches.
  • The kit number column will initially be green, but the cells will gradually fade to white over a few weeks and any newly-uploaded matches will appear as darker green - this will become very obvious when you check this report regularly.

Names & Email addresses

  • Scroll down your match list looking for familiar names or email addresses.
  • Use your browser's Search function (or Edit > Find) to look for particular names, aliases, or email addresses.  For example, search for your surname, a friend or relative's email address, AncestryDNA usernames, haplogroups that match yours, kit numbers, etc.  You might identify some matches by country by searching for particular character strings, such as: 'bigpond', 'optusnet', 'iinet', 'tpg', '.au', '.nz', '.uk', '.ie', 'btinernet'.
  • If you tested at AncestryDNA, 23andMe or MyHeritage, you might find email addresses for matches you have not had success in contacting via the testing company's messaging system.

Total centiMorgans (cMs)

    • The total amount of shared DNA is measured in units of genetic distance called centiMorgans (cM) and this is used to estimate your relationship to your match.
    • Lookup the total cMs on the reference table at the ISOGG Autosomal DNA Statistics page to estimate the possible relationship (or range of relationships) between you and your match.  Below is an extract from the table.  Click on the link above or on the table below to open the ISOGG relationship charts - there are 3 different charts on the page, so scroll right down and look at them all.  Note that this page also contains information on testing company differences, adjustments for X-DNA, and formulas you can use to convert cMs into percentages.

      Extract from ISOGG Autosomal DNA Relationship Chart

 

  • Regarding the 'largest cM', generally, the larger the biggest individual segment, the closer the relationship.

Sorting

  • By default, the One-to-many matches results are sorted by the Gen column, in ascending order.
  • The little red and blue triangles  just below the headings are used for sorting.  Red denotes the currently-sorted column.  Click on any of the blue triangles to re-sort the list by that column.  Triangles pointing upwards sort ascending (lowest to highest value) and triangles pointing downwards sort descending (highest to lowest value).
  • Experiment with the column sort arrows to re-arrange the results.  You may like to sort by largest segment, X-DNA, haplogroups (eg. if looking for any kits that match yours), or name/alias.
  • Sorting by kit number will show AncestryDNA matches first (ascending) or your 23andMe matches (descending). The most recently uploaded kits will be shaded green.
  • You can sort by email address to find see which kits with the same admin match you or which of your own kits match another kit that you are looking at (for this purpose, also use your browser search, and see User Lookup below).
  • If you have a large number of close matches, many of your genealogically-relevant matches may be below the 2000 cut-off at the bottom of the report, so sorting on other columns will bring a different 2000 to the top.  If you use the new Tier 1 One-to-many matches report, you can adjust this limit up to 100,000.

 

Thresholds

There are two measures to determine if a DNA match is genealogically-relevant: cMs (centiMorgans) and SNPs (pronounced 'snips': see ISOGG Wiki Genetics Glossary).

  • To be genealogically-relevant, a match should share a segment of DNA that is at least 7cMs and 700 SNPs.  It is best to look at segments greater than 15cMs, as there will be more chance that the Most Recent Common Ancestor (MRCA) will be within the time frame of genealogical records.
  • The One-to-many matches list uses a default of 7cMs, but does not show the SNPs. If there are any matches included whose largest segment is less than 7cMs, they will be highlighted in pink.
  • Once you have identified an interesting match in the One-to-many matches report, click on the blue 'A' to run a One-to-one comparison report (see below).
  • The default thresholds for the One-to-one comparison report are 7cMs and 500 SNPs, but these can be reduced (eg. say to 5cMs and 500 SNPs) to look for segments that may be just below the thresholds.  But try to avoid reducing thresholds unless you have already confirmed the connection through testing other relatives and/or through genealogical research.  Don't try to force matches that may not be real or are far too distant.  Concentrate on your closest matches first.  Encourage other relatives to test, which will give you useful matches that will help you identify shared matches. If you lower the thresholds enough, you can match almost anyone you want to match!
  • ISOGG Identical by Descent explains thresholds, including those used by the testing companies.

 

X 'One-to-many' matches

Although the regular One-to-many matches report includes an X-DNA column, it focuses on autosomal DNA (chromosomes 1-22).  To see your highest X-chromosome matches, you can use the same report but you will need to change the selection from Autosomal to X.

Use this report to look for any kits that share high amounts of X-DNA with you but little or no autosomal DNA.  Such matches often don't show in the One-to-many matches report even if you do a descending sort on the X-DNA total.  Cells shaded pink indicate that the largest segment is lower than the report's threshold.

 

Gedmatch X Oneto-many matches report

 

Be aware that you will need to match on quite a large segment of the X-chromosome to be genealogically useful, as X-DNA can be passed intact through female > male > female generations, so it may originate from much further back than you might expect.

Do check and understand X-DNA inheritance though, as good X-matches can help you identify which ancestral line you connect on.  Some 3rd and more distant cousins won't share any autosomal DNA with you, but you may still share some X-DNA.

Before analysing X-matches, make sure you understand X-DNA's helpful inheritance patterns and read X-Chromosome Recombination's Impact on DNA Genealogy.

Read more about the X-chromosome and find more resources on X-chromosome testing in the ISOGG Wiki.

 

'One-to-one' compare

When you have found an interesting match in your One-to-many matches report, or want to compare your DNA to someone else's kit, run the One-to-one compare report.

You can access this report directly from the GEDmatch dashboard, or you can click the blue 'A' next to the kit in your One-to-many matches report, and it will open in a new tab on your browser.

Simply enter the two kit numbers, leave the defaults as they are, and click Submit:

 

Gedmatch One-to-one compare entry form

 

 

This report shows you which segments of autosomal DNA (chromosomes 1-22) you share with your match.  It produces a list of the chromosomes and the location(s) on the chromosomes.

If run at the default thresholds (7cM and 500 SNPs), the text at the bottom of the report will include the estimated number of generations back to your Most Recent Common Ancestor (MRCA), as well as the total cMs shared and the largest segment shared.

 

Gedmatch One-to-one compare report 

 

Refer back to the ISOGG Autosomal DNA Statistics page which contains three relationship prediction charts based on total shared cMs and percentages.

If you do want to change the default thresholds, you can do so on the input screen where highlighted (eg. try 5cM and 500 SNPs).  This is useful when one or more siblings matches a cousin, but another sibling does not.  By reducing the thresholds when comparing that sibling to the cousin, you can see if they also match on the same segment(s) but at a level below the one-to-many or testing company thresholds.  But try to avoid reducing thresholds unless you have already confirmed the connection through testing other relatives and/or through genealogical research.  Don't try to force matches that may not be real or are far too distant - concentrate on your closest matches first.  Encourage other relatives to test, which will give you useful matches that will help you identify shared matches.  If you lower the thresholds enough, you can match almost anyone you want to match!

Note that you can also select the option to show the graphic bars (chromosome browser) in your results as well as the table output:

 

Gedmatch one-to-one comparison report graphic bar

 

 

X 'One-to-one' compare

The standard One-to-one comparison report (above) does not include the X-chromosome, so you will need to run the X-DNA One-to-one report to analyse X-chromosome matches.

Note that X-chromosome inheritance patterns are different to regular autosomal inheritance.

Spend a few minutes reading about X-DNA's helpful inheritance patterns so you understand the basics and know how to make the most of X-matches.

 

Gedmatch X One-to-one matches report

 

 

People who match one or both of 2 kits

This report lists details of people who match one or both of two kits.  It is similar to the ICW (In Common With) and NICW (Not In Common With) tools in Family Finder, or Shared Matches in AncestryDNA, which identify the matches you share in common with (or not in common with) another person.  Just remember that although these kits appear in both of your match lists, they may share different segments of DNA and you may relate to them through different ancestors.

Enter your kit number and another kit number to see a list of kits that match both of you, or one but not the other. This report is very handy for finding who else might be related to you on a particular branch.  For instance, enter your kit number and that of a known cousin, and the resulting list could include relatives who descend from the same ancestral couple (or above) that you share with your cousin.  You will still need to run One-to-one compare reports to make sure they match on the same segment, but this is a starting point in finding relevant matches to compare.

The shared matches list will be shown first (example below), followed by a list of kits matching Kit 1 but not Kit 2, and a list of kits matching Kit 2 but not Kit 1.  These latter lists can be useful for instance where you have tested one parent, but want a list of all your matches who don't match that parent (ie. that may match you through your other parent).  If you have tested yourself at more than one company, you can compare two of your own kits to identify differences in matches from each test.

 

Gedmatch People who match one or both of two kits report

 

The report shows kits that match both people, including shared DNA cMs, estimated number of generations back to the Most Recent Common Ancestor (MRCA), and email address.

Scroll down to view two further sections to the report: a list of who matches Kit 1 but not Kit 2, and a list of who matches Kit 2 but not Kit 1.

If you'd like to compare these kits to each other, you can tick 2 or more of the checkboxes in the right-most Select column the click the Submit button to run a selection of cross-kit visual analysis tools (see more below)

See the Gedmatch Wiki for more information and uses of this tool.

 

Multiple Kit Analysis

As well as selecting kits for cross-kit visual analysis directly from the One-to-many matches report or the People who match one or both of 2 kits report, you can now select up to 50 kits for visual comparison using this Multiple Kit Analysis tool.  It is not always possible to select all the kits you need from the first two mentioned reports, as sometimes one sibling or cousin doesn't match the others so cannot be included/selected.

With this option there are no limitations - you can select any kit you like.  Simply enter the desired kit numbers, click Submit, and then you can select from the cross-kit visual analysis tools (see below).

 

Cross-kit Visual Analysis Tools

The list of visual comparison tools is shown below.  I will provide an example of the Chromosome Browser, the Autosomal DNA Matrix, and the Generational Matrix.  You can experiment with the other options, as their descriptions and instructions are reasonably straightforward, and more details on them are available in the GEDmatch Wiki.  The X-Matrix is similar to the A-Matrix except that it analyses the X chromosome.  The 3D Chromosome Browser allows you to compare up to 10 kits in a 3D view including a matrix end view.  The last 3 reports provide different output formats for segment information.

These tools help identify triangulation groups: ie. groups of 3 or more people who all match or overlap each other on the same segment of the same chromosome, potentially indicating that they may descend from or above the same shared ancestral couple.  Note that once you suspect that a group of kits match each other, you need to run the One-to-one compare report on each of them to each other to confirm it.

 

Gedmatch visual comparison reports

 

Chromosome Browser

The Chromosome Browser will display both a data table and a graphic bar for each chromosome where your selected kits share DNA.  Below I have shown just one chromosome.

When you select kits for this report, they will be shown compared to the first kit in the list, or the kit for which the One-to-many matches report was run.  The row numbers in the graphic bar match the kit numbers in the table.

Note the colour coding legend. Small segments under 5cM are hot pink and easy to spot and ignore, whereas the larger more relevant segments (eg. green, yellow, orange, red) are very easy to identify.

When selecting multiple kits, for example from your People who match one or both of 2 kits report, scroll down the graphic bars looking for groups of large overlapping segments of DNA.  Note the kit numbers of those who overlap each other, and do further one-to-one comparions on them to determine which kits all match/overlap each other on the same segment, as these are the ones that may be related through the same set of common ancestors.

 

Gedmatch chromosome browser

 

Autosomal DNA Matrix

After selecting your kits from the One-to-many matches report, the People who match one or both of 2 kits report, or the Multiple Kit Analysis list, your kits will be compared in a matrix format (kit numbers down the left side and also across the top).  The amounts of autosomal DNA shared between each kit will be displayed in the matrix cells.

It is a convenient way to do cross-kit comparisons, especially once you start to remember the cMs of some of the common relationships (eg. 3400 cMs for a parent/child, 2550 cMs for a full sibling, etc).  Refer back to the ISOGG Autosomal DNA Statistics charts to help with relationship estimates.

The following is simply a comparison of the first twelve kits on a People who match one or both of 2 kits report (amazingly, in this case they all match each other, but that is not always typical, as there are often a number of empty cells indicating no matches):

 

Gedmatch autosomal matrix

 

The colour-coded cells are also very useful, as green indicates a very close relationship, then yellow a little more distant, then orange, and finally red for very distant or no match.  This is very handy when visualising long lists of as-yet-unknown kits from the People who match one or both of 2 kits reports, as it allows you to identify parent-child kits and sibling kits and remove unnecessary kits from the mix.  In the example above, the bright green highlights what appears to be a sibling relationship between two kits.  Also notice how the first column and top row are sorted from the closest matches to the most distant.

 

Below is a pre-planned example, showing a parent, 4 children (full siblings) and three 2nd cousins once removed (half siblings).  Note that the 2nd cousins once removed (2C1R) to the tester are 3rd cousins to the tester's children.  Observe the variation in the amount of DNA shared between the 2C1Rs (the yellowish block), 3rd cousins (the red/orange block), the siblings (centre green block) and half-siblings (bottom right green block).  This demonstrates how useful this tool is for analysing known relationships, as well as for identifying unknown relationship (as above).

 

Gedmatch autosomal matrix

 

 

Generational Matrix

Further to the Autosomal DNA Matrix shown above, the Generational Matrix is very similar but presents the match data as estimates of the number of generations back to the Most Recent Common Ancestor (MRCA).  The closest relationships are shaded in green, changing to yellow, orange and red as they become more distant or don't match at all.

Underneath the matrix is a bar-line type representation of the generational information.  Names and kit numbers are on the left, and the red dots connect each person to each of the others with a black line, positioned under their estimated number of generations apart.

For example, it is one generation from you back to your parent, two generations from you back to your grandparent.  Full siblings may be around 1.2 generations back, and half-siblings may be around 1.4 to 1.6 generations back, but these can vary as they are based on the amount of shared autosomal DNA.

 

Gedmatch generational matrix

 

Phasing

If you have tested one (or both) of your parents as well as yourself, you can phase (separate) your kit into two parts - a maternal kit (M1) and a paternal kit (P1).  These new kits will be added to your list of kits on your GEDmatch dashboard. Run your phased kits to significantly reduce the number of false matches obtained from your own kit, as many false or IBC segments will be eliminated.

Another benefit is that you can get more than the 2000 match limit, as you can get 2000 per phased kit.

Phasing is also useful where you can only test one parent (eg. if the other parent is deceased).  Simply enter your kit number and your tested parent's kit number, and this tool will create a half/partial kit for your other parent's DNA.  You only inherit 50% of each parent's DNA, so you can only get a kit with 50% of your non-tested parent, but at least you can use that kit in other GEDmatch tools, such as the One-to-many matches report, People who match one or both of 2 kits, etc.

For more information, articles and references on phasing, refer to the ISOGG Wiki and to the GEDmatch Wiki.

 

Upload your Gedcom family tree file

I've noticed a lot of confusion between the words 'GEDmatch' and 'Gedcom', and you do need to understand the difference to avoid confusing yourself and others:

  • 'GEDmatch' is the name of the entity/website providing these wonderful utilities.
  • A 'Gedcom' is a type of file format that stores a family tree, and this file can be uploaded and downloaded between different types of family tree software on desktop computers and online trees.  So if you have an online tree on Ancestry, you can download a copy in Gedcom format (.ged), save it to your computer, then upload that Gedcom file to GEDmatch for others to search.  You can also import that Gedcom file into desktop software such as Legacy, make changes, save it as a new Gedcom file, then upload it to GEDmatch or elsewhere.

Once you have a Gedcom file of your family tree, simply click one of the Gedcom Genealogy Upload links at the top right of the GEDmatch dashboard, and follow the instructions.  Further information is available in the GEDmatch Wiki, so please check that if you are unsure of anything.

You can pin your DNA kit to a person in your tree.  You can search by name, place and other variables.  You can view pedigrees and descendants.  You can look for matches to your Gedcom. And you can check the User Lookup to see if any of your kit matches have uploaded a tree.

 

 Gedcom searches

  • 1 GEDCOM to all - compares one Gedcom to all the other Gedcoms in the database, looking for matches to names, dates and places.
  • 2 GEDCOMs - compares two Gedcoms and finds matching names, dates and places.
  • Search all GEDCOMs - allows you to search all Gedcoms using a range of search variables.
  • GEDCOM + DNA matches - lists all Gedcoms linked to kits that match your DNA.

When you click on people in your own tree, you can easily change who you link your DNA kits to (see image below).  Note the coloured double-helix icon that indicates a DNA kit is linked to that individual.  When on the Individual view, for any person, note the text links at the top (highlighted), as they are the links to the pedigree and descendants details.  The Search link takes you to a general gedcom search.

 

Gedmatch gedcom individual view

 

Below is an example of a Pedigree view.  Note the Home, Pedigree, Descendants, and Search links at the very top.  You can change the number of generations visible, and you can click on any arrows (visible to the right of some individuals) to go to their extended pedigrees.

 

Gedmatch gedcom pedigree view

 

These Gedcom tools are terrific, and I'm sure once you start you will spend many hours searching, comparing, and working up and down the trees, so do give them a go.

When you use the Gedcom comparison tools, if you find matching persons you can click on a link to 'confirm' them.  This adds a little green tree icon to the name in both your tree and the matching Gedcom tree.  If you come across a green tree icon, click on it to list other Gedcoms that include that person.

 

Gedmatch's Gedcom comparison confirm green tree icon

 

Refer to Kitty Cooper's post on Using the Gedcom capabilities at GEDmatch for instructions.

 

Tier 1 tools

Once you become familiar with the free GEDmatch utilities, consider donating the US$10 required to access the GEDmatch Tier 1 tools.  Once you donate, a new panel will appear at the bottom right of your GEDmatch dashboard, with four additional reports that you can take advantage of:

  • Matching Segment Report - provides a list of matching segments for each chromosome, with an optional graphic.  It helps identify which kits overlap on the same segments, and is also useful for providing data to external tools such as GenomeMate and DNAGedcom.  The image below shows an extract of the output.  The report is run for one kit number, and it lists rows of information on other kit numbers that match on the same chromosome.

    Gedmatch Matching Segment report

  • Lazarus tool - allows creation of a surrogate DNA kit of a deceased person by combining the DNA of a selection of descendants and other relatives.  Refer to the GEDmatch Wiki, The Genetic Genealogist's post Recreating a Grandmother's Genome Part 1 and Part 2, and Roberta Estes' Putting Humpty Dumpty Back Together Again.  Facebook users interested in experimenting with the Lazarus tool should join the GEDmatch Lazarus Tool group.
  • Triangulation Report - compares your One-to-many matches with each other and provides a table containing details of all those who match you and each other on the same segment (NB: 'triangulations' are groups of three: you and two others).  Maximum 400 kits.  Optional graphics display.  Below the main report is a separate listing of match details by kit number.  Very useful for identifying who matches who may descend from the same ancestor.

    Gedmatch Triangulation Report

  • Relationship Predictor - an experimental tool, only for kits that match on both X-DNA and atDNA, that calculates probable relationship paths.

 

User Lookup

This is such a useful but under-utilised tool, and many people don't even realise it is there.  You will find it very useful for finding out more about a kit, a user, a Gedcom file.  And it can solve lots of puzzles.  Just remember to only enter information into ONE box for each search.

 

GEDmatch User Lookup

 

  • Run the User Lookup tool on a kit number to see if the match has a Gedcom family tree file uploaded to GEDmatch, which you can browse through looking for familiar names and locations.
  • Run the User Lookup tool on the email address to see if the user has multiple kit numbers (ie. other relatives you can analyse) or a Gedcom family tree file linked to another kit they manage.  Sometimes a user has only one Gedcom file uploaded, but several different kits are linked to individuals in that one Gedcom tree.
  • If you forget a kit number for a contact, run the User Lookup on their email address.  The email address usually populates automatically if it has been used before in the same browser, so you usually only need to remember the first one or two characters.
  • Run the User Lookup tool on a Gedcom Id that you find in one of the Gedcom reports, to find the kit number and/or email address when they can't be found in the tree.
  • When I receive email enquiries from beginners who neglect to tell me their kit number and/or which of my kits they match, I enter their email address into the User Lookup tool to find their kit number (they usually only have one kit, otherwise they would realise the importance of providing such information).  I then run a One-to-many matches report on their kit number, then use my browser search function (Edit > Find) to search for my own email address.  Within moments I have found which kit of mine they match, and can click on the 'A' next to the kit to run a One-to-one comparison, followed by any other analyses required on their kit before responding to them.  It is quick to do, it can save a lot of time in emails going back and forth simply to learn the kit number, and the new user is usually very appreciative of what they learn once I reply.

 

Kit Management

Edit Kit Information

To update any information related to your own uploaded kits, simply click on the EDIT or DELETE link below the list of kits on your GEDmatch dashboard, and a list of all your kits will open.  Select the relevant kit by clicking in the right column, then click the EDIT link either above or below the list, and the Edit page (as below) will open.

You can then update the name, alias, email address, gender, haplogroups, privacy status, and click SAVE.  Be aware that if you are changing email addresses, the new email address must already be registered at GEDmatch.  You should have your preferred kit set to Public, and any identical kits (same person but from other testing companies) set to Research.  Leaving multiple identical kits set to Public clogs up everyones match lists and reduces the effectiveness of many of the tools (eg. Triangulation reports).

 

Gedmatch kit management

 

DNA File Diagnostic Utility

Most users only look at the DNA File Diagnostic Utility if they have problems uploading a kit, but it is interesting to see what it contains.  This utility reveals the tester's gender, upload details, number of matches, number of no-calls, and SNPs counted on each chromosome.  If you and another family member share administration of kits, before you upload a kit, you can use this tool to check that another admin hasn't already uploaded the same kit.

 

Gedmatch DNA File Diagnostic Utility

 

Learn more

GEDmatch Learn More section of the dashboardIn addition to the User Lookup tool, the Learn More box towards the top left of your GEDmatch dashboard has some other useful resources that you should become familiar with:

  • GEDmatch Forums
  • GEDmatch Wiki
  • GEDmatch FAQ page
  • DNA for Dummies
  • Site Policy Statement

Explore all these links and experiment with the tools.  Testing more relatives is also very educational, as you learn first-hand how their kits appear and compare to yours in the various tools and reports.

If you are a Facebook user, join the GEDmatch.com User Group which is a great place to ask any questions about GEDmatch.

 

Reminder

Don't use GEDmatch as a replacement for your testing company.  Remember to exploit all the tools that your original testing company offers, as only a small percentage of testers from each company may know about and use GEDmatch.  Don't neglect the matches you already have that aren't on GEDmatch, as there may be clues hidden away further down in your match list that can be uncovered by some clever searching.  Learn to use all the tools and search tricks offered by your testing company, as well as GEDmatch.

Encourage all your matches and other testers you know to upload to GEDmatch as well, then everyone will end up with more matches and have more success.

Share your kit number and a link to GEDmatch in the footer/signature of messages to your matches and/or in your profile.  Consider using a striking profile image to entice matches to click on your profile, where you can include your GEDmatch kit number and even a link to this or other guides to GEDmatch.

Good luck!

 

 

 

23 Pairs of Chromosomes. One Unique You. Get your DNA story at 23andMe.com.

 

Overall Rating (2)

5 out of 5 stars
  • Jamie O'Brien

    On the "one to many" results for Gedmatch kits, what does an asterisk after the person's name mean? I don't know if these asterisks were always there and I have just never noticed them, but many of my matches have an asterisk, while others don't, and I don't see any notation that explains these asterisks.

    Thank you.

  • Hi Jamie, The asterisk in the 'Name' column indicates that an 'alias' has been used instead of the full name of the tester. Some people choose to display initials, nicknames or usernames rather than the tester's full name. You can enter an alias on uploading, or you can Edit your kit at any time to add an alias or change what you would like displayed. If you don't add an alias, the Name column displays the tester's name. To add or change an alias, under your list of kit numbers (Your DNA Resources) on the left side of your GEDmatch dashboard/home page is an 'EDIT or DELETE' link. Click on the link, select the kit you want to change and click EDIT, enter your desired display name into the Alias field, and click SAVE. Your alias will then be shown in brackets after the kit name/number on the dashboard page. :)

  • Alan

    Rated 5 out of 5 stars

    Wow, loads of info, wish I had found this awhile back.
    One thing I find annoying is a lot of false matches. I manage my daughter in laws kit and she has 81 matches now,
    I think about 15 are good. Is there a way to remove the others from the page?
    Thanks

  • Hi Alan, Thanks for your message. I'm not sure how you are determining matches to be 'false', unless you are referring to matches on the One-to-many report that do not match when you compare them One-to-one? That is because the thresholds are tighter (7cM 700 SNPs) on the One-to-one report, whereas the threshold for the One-to-many includes matches less than 7cM (highlighted in pink) and a minimum of 500 SNPs. Before you run the One-to-many report, I suggest you increase the largest segment threshold to 10cMs or 12cMs, and your report will run very fast and only include matches with larger segments. Cheers, Louise

  • Lisa

    Rated 4.5 out of 5 stars

    Thank you for all this information. Incredibly helpful.

  • kathleen

    How would I go about finding my PATERNAL line on gedmatch with just my dna (mtdna)? No contact with either parent to obtain DNA and searching for paternal side. Any ideas would be dandy. Thanks.

  • Hi Kathleen, GEDmatch is only designed for autosomal DNA, so mtDNA can’t be uploaded or used (they are different types of DNA and can’t be compared with each other). Once you do an autosomal DNA test (such as Family Finder, AncestryDNA or 23andMe), you can upload the raw data file from one of those tests to GEDmatch. See the current sale prices that are available now for Mother’s Day. If you already know your maternal line, identifying matches from that side can help eliminate them so you can focus on the non-maternal matches. Hopefully you will get some matches that are close enough to help you identify your paternal line. Good luck! Louise

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