@Brandit, Just to add, there are a little over 16,500 positions in the human mitochondrial genome. Of those, each person only has on average about a couple dozen positions where there are nucleotide variations from the reference genome. I have 40, for example, which is a little more than average just because of my particular maternal haplogroup (J1c2).
Of the 40 variants, 10 are for my maternal haplogroup, 10 are a hodgepodge from other maternal haplogroups, and the remaining 20 are relatively common variants at positions that are easily mutable.
I think that unless a person has a family history of relatives with vision or hearing problems or cardiomyopathy or intellectual disability, etc. (i.e., common mitochondrial disease issues) it's unlikely that person will have a significant mutation in the mitochondrial genome, as they're usually much more damaging on average than in the nuclear genome. So this may be at least part of why there's a certain lack of interest in providing frequency data for mitochondrial variants.
[On another thread there was initially some confusion (including by myself) that there might be some important variants showing up in people's WGS results but that was just because we didn't realize that companies like Dante and Veritas were using the outdated Yoruba mitochondrial genome as the reference standard instead of the newer Cambridge one, and that many positions were needing to be converted from Yoruba to Cambridge. (Yoruba is built into the hg19 reference genome that both Dante and Veritas use; 23andMe switched to Cambridge several years ago.)]
*Phew*.
