Common maternal ancestor but different haplogroups

[Stathoulisjp]

My MtDNA test result reports me as being haplogroup A with 8 HVR1 differences (from RSRS). I have 'No [HVR1] matches found at this level of testing' for (1) matches heading (2) ancestral origins heading (3) haplogroup origins heading.

A researcher has identified a possible maternal ancestor (call her Sara) and a 7 people (call them 1-7) who have proven maternal links to Sara. The researcher has pointed out that my haplogroup A differs from the haplogroup K reported by 1-7 and queried this with me.

Which is more likely? My haplogroup result is wrong and I am actually K not A? The researcher is wrong: I do not share Sara as a common ancestor with 1-7? Both my haplogroup A and my maternal link to Sara are correct; in other words is it possible for descendants from a common maternal line (i.e. my great great ... grandmother Sarah to belong to different haplogroups (A and K in this case)?

[ltd-jean-pull]

By "maternal" do you mean matrilineal or not?

[Stathoulisjp]

I meant matrilineal, apologies.

[ltd-jean-pull]

Sara can not be the matrilineal ancestor of both you and the other group of people. She can be the matrilineal ancestor of either you or them, or neither, but not both.

[Stathoulisjp]

Thank you!

[Stathoulisjp]

Some more data which I'd appreciate input on. My sequence is identical to theirs (the group of 7) with the following exception: my first sequence result is T16093Y whereas the group of 7 are either T16093Y or T16093C. Is it possible to share the sequence bar this one exception, yet not share the haplogroup?

My sequence (A haplogroup)
T16093Y, A16129G, T16187C, C16189T, T16223C, T16224C, G16230A, T16278C

Their sequence (K or K1a-T195C! haplogroup)
T16093C or T16093Y, A16129G, T16187C, C16189T, T16223C, T16224C, G16230A, T16278C
C146T, C152T, A247G, C497T, 522.1A, 522.2C, 315.1C, 522.3A, 522.4C

[Emona]

This is becoming interesting.

There is only HVR1 result for you. That is, only a small part of the mtdna molecule (the part called HVR1) was tested.

Sometimes, rarely, when there is only HVR1 result available, the mtdna haplogroup can indeed be assigned wrong.
Why? Because rarely, only HVR1 can be equal or similar in two different haplogroups. The difference is visible in more detailed result.

If this is what happened in your case, it would be possible that you are a K, and maybe even a matrilineal relative of the same Sara.

A more detailed test, that is, adding
-at least HVR2 (another part of mtdna molecule),
-or, in ideal case, the whole sequence (complete molecule), would show correct haplogroup without any doubt, and also more detailed, with sub-group.

Just a thought: as far as I can see, A is mostly AmericanNative/Asian. K is more European, but also West-Asian, and parts of Africa. How does this sound compared to your matrilineal ethnic background?

By the way, I am not a scientist. Can anyone please tell me what does T16093Y mean? I mean the "Y". Is this instead of D-deletion? No result-unknown? I only know of A/T/C/G substitutions, insertions (like .1A) and deletions (marked - or D).

[Stathoulisjp]

@ Emona, thank you. It makes sense that the limited test can produce erroneous haplogroup categorization.

It makes sense too that I should do a more detailed test to resolve the haplogroup inconsistency.

My matrilineal ethnic background is more likely to be K, with my maternal great-grandmother being a South African Afrikaner almost certainly of Dutch descent.

[Ann Turner]

Has it been a very long time since you received your mtDNA results? FTDNA implemented a "backbone" haplogroup test some years ago, which tests a SNP in the coding region to determine the top-level haplogroup. It should be able to distinguish between A and K. I'd suggest writing to the help desk and asking if the backbone test has been done.

Y is a special code for a mixture of C and T in your cells. This mixture is called heteroplasmy. Virtually everyone would have some heteroplasmy if we could look at every single cell individually, but it's only reported when it reaches a level of 20%. 16093 happens to be a hotspot for heteroplasmy.

[Stathoulisjp]

@ Ann, very useful thank you. My MtDNA results were completed in May 2012. I'll contact the help desk regarding the backbone test.

[Emona]

Ann, thank you for your explanation.

[Anizio]

There is one important possibility to consider, and its the first thing that came to mind when I read

"A researcher has"

People make mistakes, especially lazy "professions" and uninformed amateurs.

I'd have someone else go over your genealogy information to confirm it is actually accurate and there is not an error where you have accidentally traced the line of someone with the same name at the same time in the same place...but who was a different person than your ancestor.

[Stathoulisjp]

There is one important possibility to consider, and its the first thing that came to mind when I read

"A researcher has"

People make mistakes, especially lazy "professions" and uninformed amateurs.

I'd have someone else go over your genealogy information to confirm it is actually accurate and there is not an error where you have accidentally traced the line of someone with the same name at the same time in the same place...but who was a different person than your ancestor.

Agreed, thank you Anizio. I am new to this and need to balance enthusiasm with caution.

[Stathoulisjp]

... I'd suggest writing to the help desk and asking if the backbone test has been done.

@ Ann, by way of keeping you in the picture, I checked with help desk about the backbone test. They responded 'A backbone test is a SNP test designed to determine your paternal haplogroup by examining your y chromosome. It is not related to your maternal haplogroup'.

I am waiting for my mother's results and will then consider doing more detailed MtDNA tests.

[Ann Turner]

@ Ann, by way of keeping you in the picture, I checked with help desk about the backbone test. They responded 'A backbone test is a SNP test designed to determine your paternal haplogroup by examining your y chromosome. It is not related to your maternal haplogroup'.

I am waiting for my mother's results and will then consider doing more detailed MtDNA tests.

The mtDNA backbone test is not a stand-alone test, so the help desk may not be familiar with the concept. It's mentioned in this FAQ:

https://www.familytreedna.com/learn/test-types/mitochondrial-dna-mtdna-test-will-learn/

But if your mother's results are in progress, they should settle the issue.