DIFFERENT 'LEAD' SNPs & SNP NAMES = SAME THING (ROX2)
A 'lead' SNP is a SNP used at the start of the phylogenetically equivalent block to represent the subclade. It is not the first, last or 'terminal' SNP, it's just one someone chose out of the equivalents to be at the start of their own list. Many different names for the same SNPs have arisen since 2014 and different equivalent SNPs also get chosen as lead SNPs by different people. This can cause confusion. YFull use Y8397 (FGC name FGC11374) as Rox2's lead SNP in their tree. YFull have also given their YFS names to some of the other phylogenetically equivalent Rox2 SNPs already named by FGC, eg. FGC11395 is known as Y8842. Alex Williamson has FGC11388 (YFull's Y8837) as the lead phylogenetically equivalent SNP in his Big Tree. YSEQ lead with FGC11369 (YFull's Y8407) in their DF27 Panel test. In 2017 FTDNA became aware of the DF27 part of the Haplotree and added their 'BY' (Big Y) names to those more recently discovered SNPs that hadn't already been named. Y8398/BY741 is sometimes used by FTDNA as an equivalent to FGC11397, FGC11369 etc.. The above SNPs are currently phylogenetically equivalent to the SNP originally chosen by members of the subclades to represent Rox2, FGC11397. FGC11397 is also available to test individually at YSEQ.net.
The Rox2 kits on the Big Tree and YFull's tree are those who have taken expensive NGS tests and submitted results for analysis. They represent only a small proportion of the total number of Rox2 matches distributed across several FTDNA projects. Most have no SNP results, NGS or otherwise. Comprehensive NGS tests, like FGC or Big Y, taken in conjunction with 111 STRs, are the ultimate hi-res DNA genealogy combination at the moment. Those using this combination of tests are taken as near to their most recent Rox2 SNPs and matches as is currently possible. As more matches with NGS tests share their results and appear on the phylogenetic trees like the Big Tree, much more complex SNP-defined branching under Rox2 will be revealed.
NGS vs SNP 'PACK' TESTS
Avoid SNP Pack tests. If you have a NGS test, like Big Y-700, there is currently no need for further SNP tests. NGS tests are much better than SNP 'Pack' test. If you know you are a Rox2 match there is no need for a 'backbone' SNP Pack.
Big Y highlights a Rox2 match's own dozen-or-so variously named 'family', 'private', 'novel', 'non-matching variant' or 'singleton' SNPs, i.e. ones specific to your own particular lineage stretching back from you. NGS results have the potential to fill out new or existing branches from your own particular lineage when shared on phylogenetic trees.
Rox2 SNPs: R1b-P312>ZZ11>DF27>ZZ12>FGC78762>ZZ19>Z34609>Z2571>FGC11380>(FGC11397 & a few dozen phylogenetic equivalents). YFull name: R-Y8397
R1b-P312
R-Z40481 (STR)
ZZ11 (position hg19 22286799 C>G/hg38 20124913 C>G)
DF27/S250 (position hg19 21380200 G>A/hg38 19218314 G>A)
ZZ12_1 (position hg19 19736631 T>C/hg38 17624751 T>C)
ZZ12_2 (position hg19 20442843 A>G)
Z46512 (hg38 4365426 T>AC )
FGC78762 (hg38 10777194 G>T)
ZZ19_1 (position hg19 25938772 T>A/hg38 23792625 T>A)
ZZ19_2 (position hg19 28023603 A>T)
Z34609 'Z34609 is a palindromic SNP in the Y2 region. It is an A to C mutation at position 27929277. In the BigY files, an "echo" of this mutation also shows up as a T to G mutation at position 26033124 in the Y1 region, but the true mutation is at position 27929277. As it is in the palindromic region, it may be more susceptible to a back mutation via recLOH.' Alex Williamson. (position hg19 27929277 A>C, hg38 25783130 A>C)
Y84424 (hg19 7605936 C>G, hg38 7737895 C>G) FTDNA's BY27761
BY21094 (hg19 7811558 C>T, hg38 7943517 C>T)
Z2571 (hg19 23076115 C>G, hg38 20914229 C>G)
FGC11380/Y8841 (hg19 23098886 T>C, hg38 20937000 T>C). Present on both Big Tree and YFull tree.
hg19 22220783 C>T (ambiguous region DYZ19). Big Tree only*
FGC11384 (position hg19 18406972 C>T, hg38 16295092 C>T)
FGC11385 (position hg19 14422221 G>T, hg38 12301496 G>T)
Rox2
Rox2 Equivalent Block
Most often mentioned 'lead' SNPs of the dozens of equivalents:
FGC11374/Y8397 (position hg19 4062768 G>C, hg38 4194727 G>C )
FGC11395/Y8842 (position hg19 14861066 C>A, hg38 12749132 C>A )
FGC11397 (hg19 7332619 G>A, hg38 7464578 G>A)
Y8398/BY741 (hg19 7907577 C>G, hg38 8039536 C>G)
FGC11388 (position hg19 2851690 A>G, hg38 2983649 A>G)
FGC11369/Y8407 (position hg19 19250454 A>G, hg38 17138574 A>G)
FGC11381 (hg19 6720487 C>T, hg38 6852446 C>T). Found in Boscombe Bowman - deamination?
The Tree of Mankind from FTDNA (Mike Sager lecture February 2020) link