Thank you. Since I posted my question, FTDNA has updated terminal SNPs for the group where named SNPs are available; however, we have two men with 1nv and 2nvs on a branch with 9 unnamed SNPs one of which should be their terminal SNP. How do we get names for those 9 unnamed SNPs? We expect a similar situation on another branch when two more results are reported for our group. Lindsey In that regions, there ARE reliable SNPs. But to tell requires lots of investigation using IGV as well as BLAST/BLAT. That SNP is in a particular spot that, using the only build 38 BAM file I have (my own) shows all reads as map quality zero. In build 37 it shows map quality variable 0 to 3, with lots more reads showing. These are all bad signs. It also depends on read lengths. Some BigYs were done at 101 length, some 160 and a few even more. Thank you for your reply. There is a very very big difference in map quality in that area, whih reads 160 long being more reliable than 101 and 250 much much more reliable. Those files might have different normal read lengths. Build 38 will not in general provide any benefit for almost all SNPs. Of the 38 build 38 (yes, the same number) BED/VCFs I've received only a very few have made "naive statemets" that I should add a SNP to or remove one from my tree. And all of these are clearly borderline cases. Most have been cases where the number of "reads" has crosses the "low read number" theshold". You should at least examine the VCF files of those three people for such things as read numbers and map quality. Doug McDonald