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  • Wow! Skewed results by competing companies?

    After banging my head against the proverbial wall with regards to why I am so far off in genetic difference from family members I noticed that a person in my group has tested himself twice. Not only that, they were with competing companies (Genographic Project and FTDNA), but he was a genetic difference of three off with himself!!! How is this possible?

    His Y search numbers are 7ET93 and R4UXJ. The contact info is the same as well as the Immigrant Ancestor. I have sent an email to him but this skews the results of our project significantly and opens the door to several other questions.

    Can anyone shed some light on this?

    Cheers.

    Kit # 72248
    Y Search 9epze

  • #2
    Write FTDNA and Genographic. USE CAPS!!! FTDNA and Genographic are not competitors, FTDNA is a sponsor of Genographic and the University of Arizona lab does tests for both, did tests for both, before FTDNA opened their new lab in Houston.

    It ain't just about you! If FTDNA/Genographic/UofAZ cannot assure consistency all are flocked.

    Last edited by tomcat; 8 December 2006, 08:21 PM.

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    • #3
      I'm sure more than one person has done testing at different companies. Has anyone found any research out there about accuracy and how often there are mistakes?

      scot

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      • #4
        Originally posted by SaintManx
        Not only that, they were with competing companies (Genographic Project and FTDNA), but he was a genetic difference of three off with himself!
        To be fair, the difference is solely in the STR DYS389i: Genographic shows 16, whereas the direct FTDNA test yielded 13.

        Since FTDNA actually ran both tests, it should not be difficult for the customer to convince the company to review both results and determine which result is correct and which was in error.

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        • #5
          Originally posted by scotdna
          I'm sure more than one person has done testing at different companies. Has anyone found any research out there about accuracy and how often there are mistakes?

          scot
          I tested at two different companies and received identical results.

          John

          Comment


          • #6
            Originally posted by lgmayka
            To be fair, the difference is solely in the STR DYS389i: Genographic shows 16, whereas the direct FTDNA test yielded 13.

            Since FTDNA actually ran both tests, it should not be difficult for the customer to convince the company to review both results and determine which result is correct and which was in error.
            While the difference is only in one STR, it is a significant difference of three. The charts and graphs that science espouses with regards to MRCA is based on the sum total difference. I have been concerned about my results not matching with my project, and this has caused sum disarray amongst my family. FTDNA also has suggested after looking at our project and my results that I am not related to these people and that I may have an adoption/illegitimate birth in my line (which still may be the case). However, I have caught something that the company did not, and am wondering if this science is indeed exact. Needless to say at this point my confidence level has dropped just a bit- that being said, if FTDNA re-tested the gentleman in question and he did not delete his nulled scores then he is responsible at least for that. The question that needs to be answered is how can someone have a skewed value?

            Cheers.

            Comment


            • #7
              Could he have entered the info by hand and made a mistake? Why don't you get in touch with him and ask about it before getting too worked up Also, are you positive it's the same person, rather than a father and son or cousins with a similar name? The names are listed slightly differently.

              As for the genetic distance, there are two different models:

              http://nitro.biosci.arizona.edu/ftdn...ls.html#Models

              Infinite alleles - A difference in a particular marker is counted as one mutation, regardless of the absolute difference in allele values of that marker.

              Stepwise Mutation - The absolute difference in allele values is counted.

              I believe FTDNA uses the infinite alleles model, but I'm sure someone will correct me if I'm wrong

              Comment


              • #8
                Originally posted by efgen
                Could he have entered the info by hand and made a mistake? Why don't you get in touch with him and ask about it before getting too worked up Also, are you positive it's the same person, rather than a father and son or cousins with a similar name? The names are listed slightly differently.

                As for the genetic distance, there are two different models:

                http://nitro.biosci.arizona.edu/ftdn...ls.html#Models

                Infinite alleles - A difference in a particular marker is counted as one mutation, regardless of the absolute difference in allele values of that marker.

                Stepwise Mutation - The absolute difference in allele values is counted.

                I believe FTDNA uses the infinite alleles model, but I'm sure someone will correct me if I'm wrong
                I have e mailed the gentleman and am waiting for his response. However, the names match, one is a diminutive form of the other, the places match, the line of descendancy match, AND the spelling of Pricilla on both entries match.

                Another poster had mentioned that the Genographic Project is/was a subsidiary of FTDNA, so I am going to assume that they may actually share the same lab or at the very least the same methods.

                I double checked the graph on the family project website and he did NOT enter one of the scores (I believe with the Gen. Proj.) so, that I must take into consideration with regard to MYSELF. But Y Search still has both scores, and am waiting for a response from FTDNA within the next week ( I hope).

                All the best!

                Comment


                • #9
                  Originally posted by SaintManx
                  Another poster had mentioned that the Genographic Project is/was a subsidiary of FTDNA, so I am going to assume that they may actually share the same lab or at the very least the same methods.

                  I double checked the graph on the family project website and he did NOT enter one of the scores (I believe with the Gen. Proj.) so, that I must take into consideration with regard to MYSELF.
                  1) The Genographic Project is part of National Geographic Magazine, but the official testing lab for the Genographic Project is Family Tree DNA. All results (e.g., in Ysearch) that are listed as from the Genographic Project were actually processed by Family Tree DNA.

                  2) People who enter 'Genographic Project' as their testing company probably entered their values by hand. (Family Tree DNA customers are able to upload their results semi-automatically.)

                  3) The Genographic Project presents its results for DYS389 differently from Family Tree DNA. Hence, customers must know that a conversion is necessary, and must make that conversion correctly.

                  The bottom line here is that it is easy to imagine a Genographic customer entering his results incorrectly into Ysearch; then, later, after transferring his results into a direct Family Tree DNA account and ordering more markers, uploading his results into a new Ysearch entry without bothering to delete the old one.


                  By the way, if the customer's kit number (as shown in project results) starts with the letter 'N', then the customer transferred his results semi-automatically from Genographic to a direct Family Tree DNA account.

                  Comment


                  • #10
                    Originally posted by SaintManx
                    While the difference is only in one STR, it is a significant difference of three. The charts and graphs that science espouses with regards to MRCA is based on the sum total difference.
                    Since FtDNA does the tests for the Genographic project, there has likely been just one test. The error has probably occurred while entering the results into either database.

                    Comment


                    • #11
                      Originally posted by lgmayka
                      1) The Genographic Project is part of National Geographic Magazine, but the official testing lab for the Genographic Project is Family Tree DNA. All results (e.g., in Ysearch) that are listed as from the Genographic Project were actually processed by Family Tree DNA.

                      2) People who enter 'Genographic Project' as their testing company probably entered their values by hand. (Family Tree DNA customers are able to upload their results semi-automatically.)

                      3) The Genographic Project presents its results for DYS389 differently from Family Tree DNA. Hence, customers must know that a conversion is necessary, and must make that conversion correctly.

                      The bottom line here is that it is easy to imagine a Genographic customer entering his results incorrectly into Ysearch; then, later, after transferring his results into a direct Family Tree DNA account and ordering more markers, uploading his results into a new Ysearch entry without bothering to delete the old one.


                      By the way, if the customer's kit number (as shown in project results) starts with the letter 'N', then the customer transferred his results semi-automatically from Genographic to a direct Family Tree DNA account.
                      His kit # DOES begin with an N.

                      Comment


                      • #12
                        Originally posted by SaintManx
                        His kit # DOES begin with an N.
                        Then it is a virtual certainty that the results he lists for Family Tree DNA are the correct and only ones. The entry he listed for the Genographic Project was entered manually, and the manual conversion for DYS389 was performed incorrectly.

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                        • #13
                          Originally posted by lgmayka
                          Then it is a virtual certainty that the results he lists for Family Tree DNA are the correct and only ones. The entry he listed for the Genographic Project was entered manually, and the manual conversion for DYS389 was performed incorrectly.
                          I am in correspondence with the gentleman and he was completely unaware that he had differing values. He was also unaware that he had two sets of scores on Y search. It did not seem that he was aware of a lab or any other error, SO I told him to make some inquiries. We will see...

                          Cheers.

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                          • #14
                            most likely consumer error

                            Most errors from the lab are actually the fault of the customer. Improper cheek swabs, e.g., swabbing so hard that blood contaminates the sample. Perhaps setting the swab down on a paper towel or dirty surface and placing the samples into the vials.

                            Like they always say "Garbage in, Garbage out".

                            The other possibility is the individual may have entered erroneous data or the values were not properly converted. This was a big problem for customers like myself who participated in the National Genographic program. It was a very frustrating time trying to figure it all out and putting it into Ysearch.

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                            • #15
                              Originally posted by Arch Yeomans
                              Most errors from the lab are actually the fault of the customer. Improper cheek swabs, e.g., swabbing so hard that blood contaminates the sample.
                              I did that and now my second panel Y marker results are undergoing a 3rd retest and are 3 months overdue. I don't recall any warning about excessive scraping.

                              scotdna.

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