I am trying to find clues about the unusual Y-DNA results that my father and I have from FamilyTreeDNA. Our surname is Morgan, and we always assumed it was Welsh, but we have a good paper trail to the 1750s in Virginia, but then things get murky.
I did DNA tests first a couple years ago with National Geographic's original 12-marker test. They said they had to retest it 3 times. When it finally came back they said my DYS 19 value was 10 (the other 11 markers were pretty typical for R1B1 haplogroup. Later my father tested with FamilyTreeDNA, and he came back with the same values, so we're pretty sure it's correct.
As I have since discovered in comparing results on different surname projects, on ySearch, and even on forensic DNA databases, a DYS value of 10 is extremely rare. Most people, particularly R1B1 haplogroup, are 14 or higher. I'm assuming this means there were 4 mutations on this marker between me and the typical Celtic origin person from R1B1 subclades. Is this possible or likely? Is is possible there was a multi-step mutation that deleted three or four STR repeats on this marker at once? Or is there a better explanation?
+ On the FTDNA R-L21 Plus Project, I found one person who has DYS 19=10. His most distant ancestor is from Como, Italy. But other values (I've tested 67 markers now) are different.
+ On one forensic DNA database I found 4 people with DYS 19=10. They are all listed as Hispanic Americans.
If anyone has some clues on the origin of this unusual value for DYS 19, please let me know.