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'Null' ['0'] Allele Value for DYS#425, Loc. 48

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  • 'Null' ['0'] Allele Value for DYS#425, Loc. 48

    Had FTDNA Y-DNA67/Deep Clade Test Results back with a 'Null' ['0'] Allele Value for DYS#425, Locus 48 and was told delay in my getting results was the retesting required to confirm the '0' Allele Value. I am now having a DYF371X Palindromic Pack [Panel 5] Test.

    Can anyone explain in 'plain English' about having - and any significance (or otherwise) attributed to having a - '0' Allele Value for DYS#425?

    Can anyone explain in 'plain English' the DYF371X Test; I am led to believe that this Test can uncover predispositions to certain genetic or other disorders?

    Would the results of the DYF371X Test confirm, or lead to a new sub-Clade?

  • #2
    I'm sure someone else will respond with more detail or corrections, but here's my understanding, in brief:

    - DYF371 is a multi-copy marker, with 4 copies: normally 3 'c'-types and 1 't'-type.
    - DYS425 is simply the value of the 't'-type in DYF371.
    - Sometimes the t is overwritten with a c. When that happens, there's no longer a 't' and therefore DYS425 is reported as NULL.
    - The DYF371X test will give you the values for all 4 copies.

    Results for all 48-60 panels with a NULL at DYS425 are delayed because the lab runs the test 3 times to absolutely confirm the NULL (twice on the A swab, once on the B swab, at 2-3 weeks for each run).

    NULL 425 shows up in several different haplogroups and subclades, so it's not unique to any one subclade and I'm personally not aware of it defining a subclade.

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    • #3
      Here's another brief description, from http://www.jogg.info/21/Goff.htm:

      DYS425 is part of a larger marker called DYF371. DYF371 has four alleles, three of which have a C base in a particular location adjacent to the repeat structure, and fourth has a T base in that location. DYS425 is defined as the T-associated allele of DYF371. For example, DNAFP might report the results for DYF371 as “10c-12t-13c-13c”, from which the DYS425 value is shown to be 12.

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      • #4
        Originally posted by Son_Of_Israel
        Can anyone explain in 'plain English' about having - and any significance (or otherwise) attributed to having a - '0' Allele Value for DYS#425?
        Almost everyone in E3b has DYS425=Null. Take a look at the results table for the E3b Project:

        http://www.ftdna.com/ftGroups_score_...qgt3przrrHs%3d

        DYS425=Null does not define any ISOGG subhaplogroups, because the gene copying that creates DYS425=Null has occurred often enough in human history that it cannot be treated as a Unique Event Polymorphism (UEP). Informally, however, it often defines a subclade, because the gene copying event is quite rare and hardly ever reverts to the ancestral. (In other words, once the 't' changes to 'c' due to gene copying, it hardly ever mutates back to a 't'.)

        So, for example, an easily identifiable subclade of haplogroup G has DYS425=Null. See the results table of the G Project:

        http://www.ftdna.com/ftGroups_score_...qgt3przrrHs%3d

        Of course, it is possible that the DYS425=Null entries comprise two or more, independently occurring, subclades.

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        • #5
          Originally posted by lgmayka
          Of course, it is possible that the DYS425=Null entries comprise two or more, independently occurring, subclades.
          All people in I1b2a1 are null at DYS 425. So it can represent a UEP, but is a common place for the null to occur so doesn't 'in & of itself' represent a UEP.

          I'm null at DYS 425 and HG I1a.

          Ysearch now allows you to enter null for that marker.

          Originally posted by efgen
          - DYS425 is simply the value of the 't'-type in DYF371.
          - Sometimes the t is overwritten with a c. When that happens, there's no longer a 't' and therefore DYS425 is reported as NULL.
          My DYF371 is;

          10t-11c-12t-14c

          Which would constitute my DYS 425 value?
          Last edited by Nagelfar; 14 March 2007, 02:29 PM.

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          • #6
            Originally posted by Nagelfar
            My DYF371 is;
            10t-11c-12t-14c

            Which would constitute my DYS 425 value?
            Yours is a less common case. Somehow you ended up with two 't' types. My understanding is that your DYS425 would simply have two values, 10 and 12.

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            • #7
              Originally posted by efgen
              Yours is a less common case. Somehow you ended up with two 't' types. My understanding is that your DYS425 would simply have two values, 10 and 12.
              Very interesting, I contacted FTDNA on their thoughts about it.

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              • #8
                I just realized that you said your DYS425 was reported as NULL. So definitely a good idea to email FTDNA about it

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                • #9
                  Originally posted by efgen
                  I just realized that you said your DYS425 was reported as NULL. So definitely a good idea to email FTDNA about it
                  Maybe it is the second marker that is always considered DYS425. Since it is usually given CTCC, and mine is TCTC, the second marker would appear null. However, that seems unlikely because instead of one change, if the ordering actually did figure into it, this would require three changes. I'll post here what FTDNA tells me about this.

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                  • #10
                    Heh, before I even got a response I noticed my pending results got another entry, one I've had before and one, this time, I didn't order;

                    DYF371X(DYF371X), date due; 04/30/2007, Batch; 196

                    Thomas Krahn responded to me, in part, saying;

                    "This is a clear indication for a recLOH event. Although this may be very old in history of humankind because subsequent mutations seem to have happened later."

                    I asked if it represented three mutations and he responded;

                    "Compared to what? If you start with the regular 10c-12t-13c-14c conformation, yes. First you need a recLOH to convert to 10c-12t-12t-14c. Then a single step mutation of 10c to 11c-12t-12t-14c. And finally a double step mutation of 12t to 10t-11c-12t-14c"

                    But added;

                    "We don't know enough about recLOH mechanisms, yet. So it may be completely different. If the recLOH covers the SNP but interrupts before the STR this may result in 10t-12t-13c-14c. But then we still need a two step mutation of 13c to get to 10t-11c-12t-14c. Maybe another strange mechanism happens which we don't understand, yet."

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                    • #11
                      Originally posted by efgen
                      I just realized that you said your DYS425 was reported as NULL. So definitely a good idea to email FTDNA about it
                      Thomas also said my DYS425 is listed as 'null' instead of giving a DYS425a/DYS425b because of a limitation in the database. To quote him exactly; "The programmers built the database in the wrong way before I came to Family Tree DNA. So we can't enter it to the existing database".

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                      • #12
                        I received notification a day or two ago that I was being tested for DYF371X since I also have a "Null" value at DYS425.

                        My DYF371X results are: 10c-12c-13c-14c

                        Does anyone know what these values mean?

                        -thanks.

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                        • #13
                          See my response at http://www.familytreedna.com/forum/s...ead.php?t=3819

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