GEDmatch: Wonderful Helping Hand for Genetic Genealogists

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1 Helen V. Smith Pallara, Qld, Website: Blog: Researcher, Author and Speaker ABN GEDmatch: Wonderful Helping Hand for Genetic Genealogists GEDmatch is a great third party tool that can be used in addition to the tools already available at your DNA testing company site for analysing autosomal DNA results. It is important to become familiar with your DNA company tools as only some of those who have tested on that site will have uploaded to GEDmatch. So GEDmatch is additional tools not instead of tools. Currently around 800, 000 tests in GEDmatch and around 40, 000 in Genesis. As of January 2018 Ancestry has seven million plus tests, 23andMe 5 million plus, MyHeritage 1.3million plus, FTDNA around 1 million plus and these numbers are increasing rapidly. Gedmatch is a third party website developed by programmers who are not associated with any DNA testing company. The majority of the tools available are totally free to use with some premium tools available for a small donation (US$10/month as of Jan 2018, can pay for just one month). Once you have reviewed and evaluated your DNA results and your matches on your testing company s website that is then the time to upload your raw DNA file (the results of your autosomal DNA test) to Gedmatch. Gedmatch accepts uploads from Ancestry, FTDNA, MyHeritage and can also accept files from companies using the new GSA chip eg 23andMe, LivingDNA via Gedmatch s Genesis currently in beta development but eventually the whole database will move across to the Genesis platform. Step 1 is to establish a free Gedmatch account by registering and providing an and password (consider having a DNA only address through Gmail as extra security and to avoid the problem of having to update your in GEDmatch when you change ISPs). The is required for confirmation and will be the one people use to contact you. Step 2 Once you have registered, log in, click on Generic Upload fast and read the help file for uploading your company s results. Remember before uploading anyone else s DNA file to GEDmatch please get their specific permission to do so. Step 3: Go to your DNA testing company and then follow the Gedmatch instructions. If you have tested yourself at multiple companies, while you can upload all those kits it is important to make all but one a research kit as otherwise your matches will get a match with you on your Ancestry kit, your FTDNA kit, your 23andMe kit etc. This clutters the results. As part of the uploading you are given the option of creating an alias for the kit ID. I would suggest doing this for any other person s kit you upload. The alias name you choose will then show to others as eg *GPhil where the * shows it is an alias and then whatever you have chosen as the alias. Helen V. Smith 2018 Page 1

2 Once you have uploaded you will need to wait around 24 hours for the file to be reviewed (tokenised) before you are able to use all the free tools available. This is a great time to read the Help Files, the FAQ, the Wiki and watch the three videos showing how to use GEDMatch (some are a little out of date but still show the basics). There is also a Facebook group that is quite active and helpful: GEDmatch.com User Group (closed group so will need to ask to join) You are also able to upload a GEDCom (pedigree file) from your family history program and this is useful to allow other people to determine matches. Consider at least uploading a direct blood line file. Gedmatch Tools These are the list of the free tools on the main page. The first test to do is the One to many matches You type in your kit number (found on the left hand side of the main page) and leave the default settings (7cM) as they are. If you decrease this setting you will increase your risk of false matches. Then click display results. You will then see a page with a table of results. Each kit when uploaded is given a new number and a letter code. Currently: A =Ancestry, T=FTDNA, M=23andMe. Matches that are new matches within the last 30 days will show the kit number in green, the brighter the green the more recent the match. The table will show the Gedmatch kit number, the self-reported sex, mitochondrial and YDNA haplogroups. It will also show if that person has a GEDcom attached to the DNA sample or has the sample attached to in WikiTree. Then you will see these results (shown below). The intensity of GREEN in the kit number background shows the more recent matches within the last 30 days, the brighter the green the more recent the match. Helen V. Smith 2018 Page 2

3 Under the Autosomal results you will be shown the total cm your match shares with you (usually the larger the number the closer in generation, the match is to you), then the largest segment size in cm and the guestimate in how many generations the match may be from you. In the first line below you see it says cM shared with the longest segment and an estimated 1 generation away (kit is my mother s, so very much the expected results). There are a number of visualisation tools: If you click on the blue A you will be taken to the One to One comparison tool. The next column is the shared DNA on the X chromosome. This can be useful in analysis due to the differing inheritance patterns seen in women and men for the X chromosome. For further reading see the excellent posts by Louise Coakley : You are able to select a minimum of three matches and see exactly where on each chromosome they match you. By clicking in the select box to the left of the Sex column, you can do a visual comparison on each chromosome as shown below in the 2D Chromosome browser. (The 3D Browser looks a bit complicated and I don t use it to view the chromosomes but do use it for the matrices shown below the 3D results.) Each segment is shown in a colour which equates to the size range and the pinkish bit is the centromere region. Helen V. Smith 2018 Page 3

4 This allows you to see exactly where on the chromosome your matches share DNA. You have the visual as seen in the grey box where the colour shows the size of the match (as seen in the legend) and also have the numeric match points. So person 1 has a match: ( cm) and person ( cm) also has a segment that overlaps. Remember, you have a chromosome pair on each chromosome and although person 1 and 2 have overlapping matches to me on Chromosome 1, one is a match on my paternal side and one on my maternal side. This can be shown by running the matrix tool as shown below. This is a matrix comparison of the kits and as can be seen although both these kits match me at the same area of chromosome 1 they do not match each other. The next highly recommended tool is Persons who match one or both kits. This tool allows you to start creating shared genetic relationships/networks. The results will be shown as the people who match both kits. Then the people who only match kit 1 and then another that shows only people who match kit 2. The people you are interested in will match both kits. Then I suggest running the Matrix Tool to see how (or if) the matches match each other. Helen V. Smith 2018 Page 4

5 On looking at the matrix you can see the relationships between the kits so can see that Kit 1 and T1 share a parent /child relationship as do kit2 and T4. Kits T3 and T5 share a sibling relationship. You can also run a Generations Matrix. The 3D Chromosome browser It is worth looking at this for the matrices and charts it gives although the actual bowser image of the chromosome matches can look a bit confusing, if you are not used to seeing it in three dimensions. The One to Many and the People who match one or both of 2 kits along with the Chromosome Browser and Matrix visualisations are the start of the great tools at Gedmatch that will help you analyse your DNA matches who have uploaded their raw DNA results to Gedmatch. A beauty of GEDmatch is that you are able to contact people directly using their address. Note: this is both a plus and potentially a minus, and is the reason I would suggest having a DNA only address especially if you are managing kits for other people. By typing in their address into the search box you will also find any kits associated with that which can be useful if one person is managing multiple family kits. Helen V. Smith 2018 Page 5

6 Another tool is the GEDmatch user information search tool: A new feature in GEDmatch is the Tag Groups where you are able to assign colours to known groups of people eg. You have determined these people all share DNA from the Rollason ancestors so you can colour them a certain colour, which makes analysis easier. Another tool is the Are Your Parents Related Tool. This is particularly useful in endogamous populations where you have pedigree collapse or multiple lines interconnecting. Helen V. Smith 2018 Page 6

7 GEDmatch also has a number of Admixture (Heritage tools) GEDmatch WIKI has useful information on using the many (>50) admixture calculators. Need to use appropriate calculator with appropriate reference population as testee. Also remember all the caveats around admixture analysis which is still an evolving tool. It is important to use the appropriate tool with the appropriate reference population. This is a known way of displaying the results. Another way of displaying them which can be more useful is to use the Chromosome Painting Tool and show the Chromosome Painting Reduced Size option and you will see a result like this: The Tier 1 Utilities are available at US$10 a month (can pay by the month and can pay via paypal). Most people will not use these tools until they are more experienced in DNA analysis. Helen V. Smith 2018 Page 7

8 GEDmatch Genesis Currently in beta mode. For certain companies, Genesis is the only place the raw DNA results can be uploaded due to the differences in the chip versions. Eventually, time frame unknown, the two datasets will be merged. GEDmatch is currently (as of March 2018) migrating over kit information from GEDmatch to Genesis as a trial, working on their algorithms. So coming but not yet GEDmatch contains very many useful tools for genetic genealogists It is very much worth spending some time reading the help files. Play, you won t break the site! Only the Tier 1 tools have a small fee to use, the rest of the tools are freely available but please consider a donation to the programmers when you find the tools useful as that helps them to create more new tools for us into the future. HVSresearch@DragonGenealogy.com Website and Blog: Helen V. Smith 2018 Page 8