I'm not sure if this provides any clarity. Possibly just confirms what you (
@Learner1 &
@nandixon ) are interpreting in your earlier tests. My 23andMe was run about 18 months ago and lists both rs2854122 and rs267606893.
View attachment 32621
When I try to search dbSNP for rs2854122 it indicates that they have been merged.
View attachment 32622
Not sure why they are still listed in 23andMe as having different genomic positions and different genotypes for me.
Well, it took me a while to figure this mess out (I think). The reason why
@Learner1 and I have the pathogenic C variant called at position 12706 in our VCF files from GeneDX and Veritas, respectively, is that both of those companies are using a very outdated reference system for the mitochondrial genome known as Yoruba.
Yoruba was previously used for the mitogenome in human reference genome GRCh36 and in hg19 (Veritas uses hg19). Since then, it was replaced with the Cambridge mitogenome system in both GRCh37 and the currently used GRCh38. (So far as I can tell, hg19 is a sort of hybrid of GRCh36 and 37 in some respects.)
23andMe switched from Yoruba to Cambridge in 2012.
Bottomline is that people with VCF files that use the old hg19 (which may include Dante Labs as well?) will need to check their mitochondrial positions and convert them as necessary from Yoruba to Cambridge. Many of the positions have the same numbering but some change by 1 or 2. SNPedia has a conversion chart here:
https://www.snpedia.com/index.php/MtDNA_Position_Conversions
So for
@Learner1 and myself, 12706 is actually 12705 and our calls are normal there.
(23andMe correctly reports the positions now.)