The Null 425 yDNA Project was formed to gather data and learn more about haplotypes which have a Null result for ySTR marker DYS425.
HOW TO JOIN THIS PROJECT:
At this time you must have been tested either directly via FTDNA or indirectly via FTDNA via the NGS Genographic Project to join this project. Genographic Project customers must first do the free transfer of their results from the NGS database to FTDNA's database and then must be tested for marker DYS425 (part of the 67 marker upgrade panel test at FTDNA). See the "Learn More" link at the bottom of your Genographic Project personal page for how to do the free transfer of your test data to FTDNA or call FTDNA for assistance in doing the transfer. Once you have a personal account page at FTDNA, ordered the 67 marker upgrade panel and received your results and were found to have a 'Null' at marker DYS425, to join this Null425 project follow the instructions in the next paragraph. Sign/log in to your FTDNA personal account page using your kit number and password. Then click on the JOIN PROJECTS section in the upper left part of your personal page screen. On the projects page, scroll down and find the 'Search by Surname' box. Type the term 'Null425' or 'Null 425' into the search window and click on the Search button. You will then see a description of this project. Scroll down to the bottom and fill in and verify your email address and a very brief reason for requesting to join in the comments block, etc., then click on the small join button at the bottom left of the Null 425 project description and join page. I will then get your request to join and if you are a Null at DYS425, I will approve it. That is all there is to it. Also, be sure to fill in your direct paternal line "Earliest Known Ancestor" field in the "User Preferences" section of your personal account page at FamilyTreeDNA otherwise a blank will display for that field in your entry. If you don't know the full name and details about your direct paternal line earliest known ancestor you could simply enter the surname of your direct paternal line earliest known ancestor in that field. If multiple members of your male line have been tested, only submit one person from your line to the project.
Tibor Fehér joined this project in January 2010 as Co-Admin. For questions and queries about this project, please contact Tibor Fehér. Also, if not already tested for DYF371X, people with a Null at DYS425 who are joining this project must order prior to joining this project the test for the advanced marker DYF371X to learn the specific allele values for this multi-copy marker. You don't need to know your test results for marker DYF371X when you join, but the test must at least be on order and in process. Ordering that marker test is easy and requires no new samples. It is a simple and inexpensive advanced marker test. The test for the multi-copy advanced marker DYF371X is available via your personal account page at FTDNA using the Order Tests link and then selecting the "Advanced Orders" section. Order that advanced marker prior to sending this project a "Join Request". Thank you.
This is what FamilyTreeDNA.com says about Nulls at DYS425 and its relationship to the advanced marker DYF371: DYF371 is usually a four copy marker like DYS464. Its alleles are located on the palindromes P1 and P5 on the Y chromosome. See Y Chromosome Palindromic Map
One of the copies on P5 can carry a mutation in the flanking region from C to T. This T-type allele was discovered as an independent marker and was called DYS425. Our lab has developed a test to detect the C- and T-type alleles for all DYF371 STR alleles simultaneously. This test is called DYF371X. We can see the T-type alleles and the C-type alleles in different fluorescent colors, so we can label each allele with c or t. A normal person without a NULL at DYS425 would look like 10c-12t-13c-14c for example. You will notice that in a DYS425 NULL result you don't have a T-type allele. This is because a C-type allele has overwritten the T-type allele during the RecLOH event. Other haplotypes may have two T-type alleles that may have occurred by the reverse copying process. Consequently these persons will have two DYS425 alleles. Some persons who get a DYF371 result may notice that they have an odd number of alleles at this marker (3 or 5). This occasionally happens if a deletion or duplication occurs at the large P1 palindrome. Asymmetric markers that are located on different palindromes make such events visible while regular multi-copy markers (like DYS459, CDY, DYS464) are hard to figure out their molar equivalents of alleles in each genome. If you have a deletion or duplication on P1, don't panic! Today we know that many (almost all) persons with abnormal palindromic conformations at P1 or P2 are still perfectly fertile and can produce healthy children. Even whole haplogroups (like N) carry a deletion at P1/P2 as one of their characteristic markers on their Y chromosome. If you want to find out more about possible RecLOH events, insertions or deletions on your Y chromosome we suggest ordering the markers from the Palindromic Pack (Panel 5). Source: Presentation on Palindromic Markers at FTDNA conference 2006 by Thomas Krahn
See:RecLOH at WikipediaGene Conversioni at Wikipedia
Some papers with discussion of marker DYS425:Diagnostic Y-STR Markers in Haplogroup G by Phillip G. Goff and T. Whit AtheyProject Background, Goals, Results and News Copyright (c) 2007-2010, Charles F. Kerchner, Jr. All Rights Reserved