Announcement

Collapse
No announcement yet.

Autosomal DNA Results Interpretation

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Autosomal DNA Results Interpretation

    I have new Autosomal Panel 1 tests and have read through the posts on this subject in this forum and have yet to find a clear way to interpret the results as to ethnicity, controversal as it may be. I've downloaded OmniPop and entered values and I have not been able to tell what the results are. Does anyone have a clear, simple beginners explanation on what the numbers mean or any other pointers to other websites that may be newer than the last post on this subject?

    Thanks very much for any info that you can provide!

  • #2
    On the Omnipop spreadsheet, if you move to the far right you will seek a ranking of your best matches.

    John

    Comment


    • #3
      Omnipop, ENFSI, CFS and Tribes all employ a matching algorithm that yields ranked scores or 'most likely' estimates of your allele profile's conformance to the allele profiles of various populations whose allele profiles have been published.

      Your match scores to such populations do not assure you that you share ancestry with those populations, your match scores simply indicate genetic similarity to those populations on the marker set employed.

      The marker set (FTDNA's Autosomal Panels) is used world wide (in various configurations depending on which manufacturer's kit is employed) in forensic and identity testing, hence the need for published studies of allele incidence in various populations.

      Because the markers are highly variable STR's (short tandem repeats) and are subject to recombination it is highly unlikely that any two persons would share the exact same allelic profile. Nevertheless, two persons who both descend from a genetically distinct population will show a higher degree of similarity to one another. And all people tested will show some degree of similarity to all world populations, but, obviously some matches will be stronger than others. You get to decide the relevance of your matches.

      You can post your alleles at www.dna-fingerprint.com in their online matching database Amatch to find your degree of match to other posters. There are several long running threads on this forum on this subject.

      Comment


      • #4
        Originally posted by Johnserrat
        On the Omnipop spreadsheet, if you move to the far right you will seek a ranking of your best matches.

        John
        John,

        I do not see what you are talking about. Can you perhaps, off line send
        me a screen shot or something?

        Thanks very much!

        Comment


        • #5
          Omnipop Operation

          Enter allele values in appropriate cells.

          Entering values in just the nine green-highlighted cell will return the most results as the most number of population stats are based on nine markers.*

          After entering all alleles select a cell in the inactive area of the field or no calculation can occur.

          Select 'Show Frequencies'

          After the jump scroll to the right for ranked results. There is a results column on the left that is of no use. In the rigt column the best matches will be at the top of the list with lesser matches following in descending order.

          *If you enter allele values in more than the nine green cells, the right hand side results column will show matches with 00 at the top of the column and you will need to scroll down the column until to get to matches with positive scores. Again, the best matches will be at the top with lesser matches in descending order.

          Comment


          • #6
            Forgive my ingnorance here. I did not know about clicking a blank cell, now the table populates. I cannot find this table to which you refer. I assume that it's above the complete listing of all of the results that goes on miles to the right or is this the location that you are talking about?

            Thanks very much!

            Comment


            • #7
              The results given after 'Show Frequencies' is chosen are at the bottom of a very long page and the right hand column, in addition to having matches ranked in evident order (such rank order is not evident in the results column at left) has a box above it that reads 'Return to Top of Page' and if selected you will return to the field in which you enter allele values.

              The results column will contain matches to every population in the db, about 200, although if you enter more than the nine marker data the top of the list of matches will give 00 results and you will need to scroll down the column to find positive matches to the populations that have been studied for the marker set entered.

              Comment


              • #8
                Yes, I see it now, thanks so much!

                Final question then - what are your words of wisdom regarding what the numbers mean? Or is there a good reference to which you can refer me? I realize that interpretation of these results is not absolute and still is subject to much discussion as to their relevance to ethnicity.

                Thanks again!

                Comment


                • #9
                  Omnipop ranks all matches, so the match at the top of your Omnipop list is your best Omnipop match.

                  Omnipop numbers, expressed as odds, are very big or very small, depending on your point of view. The E# is an exponent, shorthand for zeros or decimal places. If you get an E+6, you could shift the decimal 6 places one way or the other to get a whole or decimal number. If you go for a whole number then your Omnipop odds of matching a 'potential' member of that population is 1 in ______.

                  I think folks are well advised to take Omnipop results (or ENFSI, Tribes, CFS results) as impressions or sketches rather than authoritative renderings of ancestry. In my experience, looking through the lens of fuzzy logic, I find my results 'in the ballpark' ethnically.

                  Comment


                  • #10
                    I think I am getting it!

                    OK, if my top result is:

                    Chueta (Spain) (44) 3.20E+10

                    Which means there is a 1:32,000,000,000 chance of being in this group, that seems to be pretty small odds that this test has captured any ethnicity information.

                    Or am I misunderstanding something?

                    Comment


                    • #11
                      1 in 32 million is better than 1 in 33 million.

                      Are you Jewish? Lots of Jewish genetics in Cheuta, it is the tiny Spanish possession in Africa across the Straits of Gibralter.

                      Comment


                      • #12
                        This is my wife's results actually and the result is a surprise indeed as we know of links through conventional genealogy to Germany, Switzerland, Netherlands, Great Britain, Ireland. There are Jewish great-grandparents, the only Jewish roots in the bunch!

                        I certainly appreciate the help. Hopefully someone else is helped as well!

                        Comment


                        • #13
                          There is a 9-locus Jewish population sample in Omnipop. You will find it and all others under the Data tab.

                          You could compare your wife's allele profile to the Ceuta sample and see which of her alleles are most determinative of her match to that population. (Population allele incidence is given in decimals easily converted to percentages: 0.25 = 25% meaning 1 in 4 in a population has the allele.)

                          Then you could compare any alleles shared with Ceuta to the Jewish population profile to see if there are any correspondences.

                          You could do this with all Omnipop matches. You would find that among your Omnipop matches some are most strongly predicated on one subset of alleles and others on other subsets of alleles.

                          Comment


                          • #14
                            Question

                            While reading this thread I figured out how to insert alleles into the data base, but I dont understand how to interpret any of it. Is there a tutorial available?
                            Thank you
                            Ray

                            Comment


                            • #15
                              Duval,

                              No tutorial, but there is another thread you could read that contains many thoughts on this topic; 'Tribes scores'. And with a search of this forum you might also find threads titled 'Omnipop ...' that could be useful.

                              Omnipop, ENFSI or Tribes 'matches' do not assure you of sharing actual ancestry to the populations to which you are matched, they simply express your degree of fit to those populations based on your allele profile and allelic ranges of those populations. Nevertheless, some users find the results conform, usually in a broad way, to known ancestry.

                              Omnipop ranks all scores, best match first.

                              Hope this helps ...

                              Comment

                              Working...
                              X