Y-Chromosome Markers
Y-DNA 18 --The primary purpose of this test is to determine if branches can be eliminated from your family tree. The Most Recent Common Ancestor (MRCA) on an exact 18/18 match is eight generations.
Y-DNA 26 --This test will both eliminate relationships or branches from your tree as well as provide good resolution in establishing relationships to validate your genealogical conclusions. The MRCA on an exact 26/26 match is five generations.
Y-DNA 43 --This high resolution test improves the MRCA possibility between genetic cousins and common ancestors by two generations on an exact 43/43 match.
Marker Choice
The loci, or markers compared by Relative Genetics were chosen for their mutation rates, variability within populations, and reproducibility. Finding a locus with a good mutation rate for genealogical studies can be challenging as you need to have enough variability that every male tested won't have the same value, but at the same time you don't want to have too much variability or it will not be traceable. We believe that all markers we have chosen can be of value to the genealogist.
| 43 markers | 26 markers | 18 markers |
| DYS19/394 | DYS19/394 | DYS19/394 |
| DYS385a | DYS385a | DYS385a |
| DYS385b | DYS385b | DYS385b |
| DYS388 | DYS388 | DYS388 |
| DYS389 I | DYS389 I | DYS389 I |
| DYS389 II | DYS389 II | DYS389 II |
| DYS390 | DYS390 | DYS390 |
| DYS391 | DYS391 | DYS391 |
| DYS392 | DYS392 | DYS392 |
| DYS393 | DYS393 | |
| DYS426 | DYS426 | DYS426 |
| DYS437 | DYS437 | |
| DYS438 | DYS438 | DYS438 |
| DYS439 | DYS439 | DYS439 |
| DYS441 | ||
| DYS442 | ||
| DYS444 | ||
| DYS445 | ||
| DYS446 | ||
| DYS447 | DYS447 | DYS447 |
| DYS448 | DYS448 | |
| DYS449 | ||
| DYS452 | ||
| DYS454 | DYS454 | |
| DYS455 | DYS455 | |
| DYS456 | ||
| DYS458 | ||
| DYS459 a/b | ||
| DYS460 | DYS460 | DYS460 |
| DYS461 | DYS461 | |
| DYS462 | DYS462 | |
| DYS463 | ||
| DYS464 a/b/c/d | ||
| GGAAT1B07 | GGAAT1B07 | |
| YCAII a | YCAII a | YCAII a |
| YCAII b | YCAII b | YCAII b |
| Y-GATA-A10 | Y-GATA-A10 | |
| DYS635 | DYS635 | |
| Y-GATA-H4* | Y-GATA-H4* | Y-GATA-H4* |
Y-GATA-H4 follows the TAGA motif as presented by Butler et. al. Forensic Sci. Intl. 129: 10-24.
Marker Composition
In general all DNA markers, or loci, are comprised of three regions, two that are the same in most individuals, and one that can vary from one individual to another. The static regions flank the variable region and act as molecular highlighters, allowing the variable section to be accurately measured in all individuals. This measurement is reported to you as your allele value.
Multi-Copy Markers
For most of the loci tested, the short stretches of DNA that make up the flanking regions are unique to only one place anywhere in the DNA. However, multi-copy markers such as DYS385, DYS459, DYS464 and YCAII, are found in more than one place in the DNA. Because these are Y chromosome markers this means that the flanking regions are found in more than one place on the Y chromosome. That is why these markers can yield more than one value.
Evaluating DYS389
DYS389I and DYS389II should not be treated as a multi-copy marker. These two loci share one flanking region. This means that DYS389I is embedded in DYS389II. If the value at DYS389I matches and the value at DYS 389II does not, then you just have one mismatch and no special consideration needs to be applied. However, if you mismatch at DYS389I, then you need to be careful when evaluating the DYS389II values. In this example the value of DYS389I is 12 and the value of DYS389II is 18. However, because the reported value of DYS389II contains the value of DYS389I, the reported value is 30, 12 plus 18. Therefore if the value of DYS389I changes, say to an 11, then the reported value of DYS389II will drop to 29, even though no change in DYS389II has taken place.