Creating a Phased Parental Kit at GedMatch

In the article, Concepts – Parental Phasing, I explained why it’s so important to have at least one, if not both of your parents DNA tested in addition to your own DNA. Having at least one parent tested allows you to determine, at least for the matches that match both of you, which side the genetic ancestral connection is from, assuming the match is only from one side.

At GedMatch, you can utilize the kit of you and one parent to subtract out the DNA of your known parent. The results are the other half of your DNA, that of your missing parent.  Now, this technology isn’t perfect.  Let’s say for example that you have your mother, as I do, but not your father.  At one location, you and your mother both have an A and a T.  There is no way to know whether you inherited the A or the T from your mother, and which one you inherited from your father, so these situations are unresolvable.

So are areas where they are no-calls or bad reads.

In other studies that I’ve been involved with, we can obtain a significant amount of your half of the other parents’ DNA, around 40% of their entire DNA sequence. So that’s certainly better than nothing, given that you only have 50% of their DNA to begin with.

A New Series – Managing Autosomal DNA Matches

I’m going to step through how to create a second phased parent at GedMatch, because you’re going to need to do this for one of the upcoming Concepts Series – Managing Autosomal DNA Matches articles. Yes indeed, I’m introducing a new series soon – and this article is to help you prepare!

Test Your Parents and Close Family Members Now!

So here’s a big hint for the new series. If you have a parent who has not yet tested, now is the time to order that test.  You can test at Family Tree DNA or at Ancestry and then transfer your results to Family Tree DNA and GedMatch.  However, if you order from Ancestry, make sure to read this article first to understand fully the rights you are conveying to Ancestry.  Also, Ancestry is changing to a new chip, and we’re not sure how compatible their new autosomal file will be with either Family Tree DNA or GedMatch, and we won’t know until after those vendors have had some time to evaluate the new chip file results, so perhaps Family Tree DNA would be the safer bet right now for new tests, because you will need to transfer your parents results to both Family Tree DNA and GedMatch.  Yes, you will need your known relatives results in both locations, because relatives help identify match and triangulation groups.

So, order that kit today so you’ll have results and can fully participate in the new series’ exercises.  We’ll we walking through matching, phasing and triangulation vendor by vendor one step at a time to create your own matching DNA Master file.

No Parents to Test?  You’re NOT Out of Luck!

If you don’t have either parent, you’re not entirely out of luck.  You won’t be able to participant in parental phasing, BUT, you will be able to participate in other types of phasing and matching.  In order to do this, you’ll need to test as many of your relatives as possible, beginning with testing as many half or full siblings as possible.

Test any grandparents, aunts, uncles, great-aunts, great-uncles and any and all cousins that you can find and arm-twist (in the nicest way of course) too, because their matches will help you – and that goes for whether you have one, both or neither parent tested.

The only people in your family you don’t need to test are people both of whose parents have tested, or the relevant parent (to you) has tested.

For example, if your first cousin has tested, you don’t need her child too, because that child inherited half of your first cousin’s DNA, and you already have that in your first cousin’s test. However, your first cousin’s sibling is an entirely different matter, and you’ll want to test as many cousins (and their siblings) as you can find.

Creating a Parent at GedMatch

To create a phased parent, you’ll need your kit and the kit of one of your parents. If you have both parents tested, you don’t need to do this.

Sign into your GedMatch account and select the Phasing option, 6th from the top.

phased parent 1

Enter the kit number of the child, which is you, and the kit number of the parent whose DNA you do have.

phased parent 2

Click on generate.

When the utility is finished, you will receive the following message.

phased parent 3

GedMatch has created a phased maternal and paternal kit with the leading letters PM (for 23andMe kits), PT (for Family Tree DNA kits) and PA (for Ancestry kits) and the trailing letters P1 and M1. P1=Paternal and M1=Maternal.

The kit number of the child is imbedded inbetween PM and P1, so for example in PT524738P1.

These phased kits, because they are only “half kits,” can be utilized to determine which of your matches are from which side of your family.

I wrote about how to do that in the article titled, Phasing Yourself.

But let’s be very clear here, a phased kit is never as good as the real McCoy, so by all means, get that parent tested if at all possible.

Have fun and get your ducks in a row for the new series!




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75 thoughts on “Creating a Phased Parental Kit at GedMatch

  1. Roberta: Thank you for this! So, I have my Mom’s sequence, and the sequence for myself and four siblings, and the sequence of my Father’s brother. Should I create separate phase kits for each of my siblings/Mom in addition to the one I made for myself? I assume my paternal uncle’s data is not helpful from the phasing perspective. If I create phase kits for myself and sibs, would I then try to construct a composite sequence for my Dad? Will this question be discussed in your new upcoming series?

    • As an aside, you can create a Lazarus kit combining the information from all of your siblings, and you, into a relatively complete father’s kit. Here’s an article where I discussed that.

      Be careful to follow their instructions exactly. I’ve seen an awful lot of people who don’t and wind up with Lazarus kits providing inaccurate information.

      • Hi Roberta, The is very nice!
        I have tested myself and my mother, but my father passed away just one month before his kit arrived at home.
        I have used the suggested phasing to estimate his DNA results (PT212426P1) based on my own results T212426 and my mother’s one: T750035.
        If I understand I can have a better picture of his results adding other relatives. I have 2 full brithers and 2 half brothers. And 3 Aunts (sisters of my father) still alive.
        In order to create this Lazarus kit combining, which woul be the best? To test my 2 brothers or to test the 3 sisters of my father? Any recommendation?

  2. So if my parents are deceased, I can substitute my paternal aunt and my maternal uncle, who have tested, and get basically the same results? I can also FF test a paternal uncle who is deceased but has done the y-dna and Big Y, all with FTDNA. Would I need both he and his sister’s results?

    I also have tested a Great, Half Uncle on my paternal grandmother’s side. In other words, my great grandfather’s half brother. How would this one work?

    • You can only phase with a parent, BUT, all of those other relatives will be very useful as we proceed. If you can upgrade your uncles test to Family Finder, do, because each child gets DNA and matches their siblings don’t.

  3. I love your blog and follow it regularly. However, today you teased those of us with no parent to test by saying, “no problem,” and then proceeding to tells we needed one parent for the process you described! Please explicate.

    • You do need one parent for phasing. But you won’t be left out of matching and the rest because you don’t have a phased parent. I’ll go back and review to see if I can clarify that.

  4. I have tested my Dad but missed my Mum now deceased but have tested my Mums sistet
    Where does this fit in ?

  5. Can you use a Lazarus kit? I’ve built for my deceased mother that ended up with 3050 cM’s. Will that work?

    • I’ve not tried that. My only concern is that some people don’t create the lLazarus kit correctly. So why don’t you do a phased kit and you can experiment with both.

  6. This is great! My mother’s kit is being processed right now, and mine should not be too far behind. Thanks for doing this.

  7. Roberta,

    Mark Muir here. I read your blogs via e-mail and I just read this one… minor correction here:

    “GedMatch has created a phased maternal and paternal kit with the leading letters PM and the trailing letters P1 and M1. P1=Paternal and M1=Maternal. The kit number of the child is imbedded inbetween PM and P1, so for example in PM524738P1.”

    The leading letter is actually only “P”, and yes, the suffixes are P1 for Paternal and M1 for Maternal. You may have a 23andMe kit in where it looks like it begins with PM, but the first M actually refers to your example kit you cited, in this case, a 23andMe kit (P then M524738 then P1).

    So my phased kits are PA336194P1 & PA336194M1, for example, because I am using my Ancestry kit, A336194. Cheers!

    Mark E. Muir

    • That’s really interesting, because the 524738 number is my FTDNA new number to replace my old kit number, so these are definitely NOT 23andMe kits and they do have the PM leader. So now I really wonder if the leading P plus the P1 and M2 suffix is the only designation we can depend on for sure for phased kits.

      • Oh, that is quite interesting, indeed! I am surprised with the new wrinkle regarding FTDNA kits from “F” to “T” that they didn’t simply create: “PT524738P1” and “PT524738M1” kit for yourself. Perhaps they made an error in their algorithm and applied M when they meant your T524738 “normal” FTDNA kit?

  8. Well, my kids kits are phased, but since I’m an only child with deceased parents I have tested cousins on both maternal and paternal sides, but only have one distant male cousin on my dad’s side and no males on my mom’s.Makes it somewhat difficult! ( That’s ok, the whole bunch of us are “unique” no really close matches to any of us–dropped by aliens?)

  9. Roberta, I am confused about the different aps on Gedmatch admixtures. They do not seem to make sense to me. Can you explain what they mean on one of your blogs?

    • Because these tools were each written and contributed by a different person, there is no standardization. Furthermore, in the past, my attempts to contact the submitters with questions have not always met with success. My suggestion would be if you have a question, to contact the individual who submitted the application and hope they answer. I’m sorry, but there just isn’t any standardization in how these applications work or even the reference populations they are or may be using.

  10. Regarding phased parents, I have my mother’s DNA, like Roberta does, but not my dad’s. But I also has my sister’s autosomal DNA. So I phase my mom and my sister and run a one-to-many query on my sister’s phased kit’s X-DNA . Voilà! I now have my dad’s X-DNA matches.

    On Wed, May 18, 2016 at 8:47 AM, DNAeXplained – Genetic Genealogy wrote:

    > robertajestes posted: “In the article, Concepts – Parental Phasing, I > explained why it’s so important to have at least one, if not both of your > parents DNA tested in addition to your own DNA. Having at least one parent > tested allows you to determine, at least for the matches th” >

    • Make sure you have the correct kit numbers is the correct location – and that you have chosen the Phase option. If the problem persists, then contact GedMatch.

  11. I have a lot of test kits that I manage and have never been able to see the base data which I think should be the letters A, C, G and T. How do I see them so I can print them out? Are they the same for all types of kits?

  12. Well for example in your 2nd paragraph under Concepts.I m near he end and want whoever finishes the task to have everything I have available to work with. You always go back to the raw data if something isn’t working.?

  13. Phasing my father seemed simple. How does this differ from Lazarus? Do both only go out one generation? I need to go out 3 generations (great-grandfather). And, finally, I can’t find Lazarus or “At, I selected the Tier 1 (subscription or donation) option of Lazarus and was presented with this menu.” I followed Gedmatch directions from their web site.

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  15. I’m new to some of this so this may be a stretch, but I have DNA for myself, my father, and my mother’s mother. By the process you’ve described I can use my father’s and my kits to phase results for my deceased mother. But, depending on the strength of my mother’s recreated profile, could I then use hers and her mother’s to try to phase one for my deceased grandfather?

      • This is not entirely accurate. Approximately 25% of your data comes from your deceased grandfather, and once your DNA is phased you should be able to readily identify the 25% that comes from the deceased grandfather. You know the 50% of your DNA that comes from your father. You also know the approximately 25% of your DNA that comes from your mother’s mother. Everything left over is from your mother’s father. It will be a partial kit, not a full kit. But technically no kit is a “full” kit. Different companies test different SNPs. Nobody tests them all. Your grandfather’s kit will just be on the smaller side.

  16. You have really helped me learn about triangulation, phased kits, etc. I don’t know if you have written on this topic but – I tested at Ancestry & uploaded raw DNA to GEDmatch. Yesterday, I learned my daughter has tested – but at 23andMe. My question is twofold: I have her raw dina zip file & will upload to GEDmatch. However, my gedcom that has been uploaded does not include her. Do I need to upload a new gedcom that includes her – or is there a way to “add” someone on my family tree at GEDmatch? Also, does it make a difference that she tested with a different company and I when I upload the raw data? Thanks!

    • It doesn’t make any difference that you two tested at different companies, except you’ll select a different upload option. I don’t think it matters that she is not in your Gedcom file either. I don’t know of any way to change that at GedMatch, but I don’t use those files much there.

  17. Me, my paternal aunt and her daughter have all tested and are uploaded at gedmatch. I do not have a living parent to create a phase kit with but I can create one for my aunt and cousin which could also help me with my matches… right? I’m trying to break down several genealogy brick walls.

    Thank you!

      • Isn’t it better to use phased data for the aunt’s for matches? I thought unphased data was less accurate, especially for the smaller segments. I saw one study where 90% of unphased segments 5 centimorgans or less were not really accurate matches. The daughter’s data can be used (in combination with other matches) to phase the aunt’s data. I know it will take a little more work to figure out the recombination points. At a minimum, she can use her cousin’s phased data, and also create an “evil twin” of the data that her cousin did not inherent. Then use the cousin’s phased data and the evil twin’s phased data to look for matches while avoiding errors in the smaller segments. Anytime someone wants to get tested I would encourage it. And anytime someone is making their data available I would use it. While it is true that cousin has the DNA of the aunt, the aunt’s data is not phased so using the cousins data will indeed help.

      • This comment should be read after reading my comment that immediately follows below. I just read another article on your website that shows the importance of using phased data:

        The analysis on that page shows that 12% of the unphased data matches of 10 cm or greater were erroneous: “Truthfully, I was surprised to lose 97 matches at 10cM by having them match neither parent. That’s about 12%.”

  18. I entered my kit number and my mother’s. I got an error because I didn’t enter my father’s, who’s deceased. Help!

  19. Pingback: 2016 Genetic Genealogy Retrospective | DNAeXplained – Genetic Genealogy

  20. I just did the phasing with my kit and my father’s kit. I went back to my home page and there wasn’t another kit# I did it again and got the same results. I copied the results this time and I am going to paste it this note. I tried the kit numbers they gave and nothing. I wanted to contact Ged match but couldn’t find a ph#

  21. Hi Roberta, I hope you are fine. My Dad died 7 years ago. So I took my moms DNA and my DNA and did the phasing. Now I got Dads DNA and go to the One-to-many comparison. All my close family members show up in the cm range as they are supposed to. When I am looking at my uncles match, he only shows with 864 cm to my fathers phased DNA – that is in a 1st cousins range.

    We just found out half a year ago, that my uncle and my Dad had different fathers. So they are actually half siblings. But with 864 cm they are cousins? Before I jump to any other conclusion, maybe my uncle just shows 864 cm to my Dad because I did the phasing (Me and Mom – 50% of my DNA are Moms / 50% of my DNA goes back to Dad) and the other 50% on my Dads side are missing?

    I am sure you will have an answer. Thank you.

    Best, Manon

  22. Hello!
    I took’s DNA test and I uploaded it to GedMatch. Now, if I wanted to test my parents too, should I buy them an Ancestry Kit each, or would it be better to mix it up and get, say one of them to take the MyHeritage test and the other take the 23andMe test? or is there no difference for what raw data is worth?


  23. I have phased mine and my mothers dna as I am the manager of her kit, but my daughter has her own account for her dna, so how can we phase, mine and hers, as her kit doesn’t show up in my options, and mine is not available to her.

      • Thanks! That explains the problems I have been having.

        I created a Lazarus kit for my deceased brother using his daughter, my niece, in group 1 and in group 2 I put myself, two additional brothers, two paternal uncles, one paternal aunt, several paternal cousins, as well as several maternal cousins. The kit came out at 3447 cM of matching DNA. However, when I look at the one to one comparison with his daughter, it shows almost all of the 1-22 chromosomes matching, but showing a green full match. The X chromosome shows a full half match, as it should.

  24. Hi, Roberta, please help me understand. I’m female phased my dna (ancestry) and my brother’s (23andme) with my father’s (FTDNA). Is this reliable, given the different companies?
    1. When I compare the X chromosome of my brother’s M1 (maternal) file with his P1 (paternal) file, I get an error that says that both files should have an X chromosome for comparison, implying that one doesn’t. It seems correct. The P1 shouldn’t have an X and the M1 should.
    2. When I compare my brother’s M1 file with my M1 file, I get some segment matches on chromosome X, after all we have the same mother. So, I agree with this.
    3. When I compare my P1 file with my brother’s P1 file, I get full match on the chromosome X! How is it possible? He shouldn’t have an X chromosome from my father. Does it assume full match when nothing is there in his P1 file?
    4. When I compare my M1 file with my brother’s P1 file I get some segment matches on chromosome X (and on chromosome 16)! But he shouldn’t have a P1 X chromosome.
    I don’t understand 3 and 4 at all because I don’t know what is in the P1 file for my brother. I used the X one-to-one and also the multiple kit analysis on 3 and 4.

  25. “GedMatch has created a phased maternal and paternal kit with the leading letters PM (for 23andMe kits), PT (for Family Tree DNA kits) and PA (for Ancestry kits) and the trailing letters P1 and M1. P1=Paternal and M1=Maternal.”
    For me Gedmatch created only: P1=Paternal and M1=Maternal.”
    How do I do PT (for Family Tree DNA kits) to transfer them to the FTDNA?

    • You don’t do anything at Family Tree DNA. This is entirely through GedMatch. You cannot transfer the kits anyplace outside of GedMatch.

  26. Thank you. What software programs for PC would you recommend that allow to do Phasing and transfer the other part of parent t to the FTDNA?

    • You can’t go that. They use imputation and they will catch a half kit. It’s not something customers should be attempting to do. GedMatch can do it internally because they don’t use imputation, they match very disparate kits and they know internally they are dealing with a “half” kit.

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