Birth-parent search advice

[robdrew7]

I've been looking for my mother's birth-parents, using the names on her birth certificate, Michael J. and Mary K. Recently a niece of the lady I was researching agreed to take the Family Finder test. This lady's mother Sarah K. had a sister named Mary K. She and my mother tested as first cousins - hurrah! I believe I've identified my mother's birth-mother.

I'll call this new first cousin "Linda" and my mother "Jane". A few weeks later, new-cousin Linda's mt-DNA test returned. She and my mother don't match, one is U5 and the other H. What do I do with that information?

As I understand things, first cousins share one set of grandparents. The mt-DNA of the grandmother is passed to all her children, and her daughters (Sarah R and Mary R) pass it to their children. The theorized link was along the female line from the grandmother to both Linda and Jane.

1) Am I wrong about how mt-DNA is passed?

2) Does this mean Jane's birth-parent is Linda's uncle instead of her aunt?

3) Or is there another scenario I'm overlooking?

4) Should I retest my mother's mt-DNA to see if an error was made previously?

I'd appreciate your help!

Rob

[Frederator]

Wow, that's a stumper.

Any chance that this new woman's mother was only a 1/2 sister of your mother?
On the father's, rather than their mother's side?

I've been looking for my mother's birth-parents, using the names on her birth certificate, Michael J. and Mary K. Recently a niece of the lady I was researching agreed to take the Family Finder test. This lady's mother Sarah K. had a sister named Mary K. She and my mother tested as first cousins - hurrah! I believe I've identified my mother's birth-mother.

I'll call this new first cousin "Linda" and my mother "Jane". A few weeks later, new-cousin Linda's mt-DNA test returned. She and my mother don't match, one is U5 and the other H. What do I do with that information?

As I understand things, first cousins share one set of grandparents. The mt-DNA of the grandmother is passed to all her children, and her daughters (Sarah R and Mary R) pass it to their children. The theorized link was along the female line from the grandmother to both Linda and Jane.

1) Am I wrong about how mt-DNA is passed?

2) Does this mean Jane's birth-parent is Linda's uncle instead of her aunt?

3) Or is there another scenario I'm overlooking?

4) Should I retest my mother's mt-DNA to see if an error was made previously?

I'd appreciate your help!

Rob

[vinnie]

I've been looking for my mother's birth-parents, using the names on her birth certificate, Michael J. and Mary K. Recently a niece of the lady I was researching agreed to take the Family Finder test. This lady's mother Sarah K. had a sister named Mary K. She and my mother tested as first cousins - hurrah! I believe I've identified my mother's birth-mother.

I'll call this new first cousin "Linda" and my mother "Jane". A few weeks later, new-cousin Linda's mt-DNA test returned. She and my mother don't match, one is U5 and the other H. What do I do with that information?

As I understand things, first cousins share one set of grandparents. The mt-DNA of the grandmother is passed to all her children, and her daughters (Sarah R and Mary R) pass it to their children. The theorized link was along the female line from the grandmother to both Linda and Jane.

1) Am I wrong about how mt-DNA is passed?

2) Does this mean Jane's birth-parent is Linda's uncle instead of her aunt?

3) Or is there another scenario I'm overlooking?

4) Should I retest my mother's mt-DNA to see if an error was made previously?

I'd appreciate your help!

Rob

Rob,

Sorry, but based on the mtDNA results, Linda and your mother can not possibly share the same direct maternal ancestor. Two women directly descended from the same woman will match each other and the woman in their mtDNA haplogroup. I'll leave it to others to address the FF results. Of course, you can always ask the office to recheck the mtDNA and/or FF results.

Vinnie

[JOlson]

Since you gave Mary and Sarah both a 'K' for the last name, does that mean you know they both have the same maiden name?

What are Jane and Linda's Autosomal and X comparison cM results?

[Linds]

Wow, that's a stumper.

Any chance that this new woman's mother was only a 1/2 sister of your mother?
On the father's, rather than their mother's side?

This sounds like the only plausible explanation.

[efgen]

Recently a niece of the lady I was researching agreed to take the Family Finder test. This lady's mother Sarah K. had a sister named Mary K. She and my mother tested as first cousins - hurrah! I believe I've identified my mother's birth-mother.
...
A few weeks later, new-cousin Linda's mt-DNA test returned. She and my mother don't match, one is U5 and the other H. What do I do with that information?

How is Linda related to the woman you're researching? She could be a niece through the woman's sister or through the woman's brother.

If she's a niece through the woman's brother, then that's why the mtDNA wouldn't match. Linda has the mtDNA of her own mother, not of her father's mother.

But if Linda is a niece through the woman's sister, then the mtDNA should have matched if the woman's mother and your mother's mother were indeed sisters.

Elise

[robdrew7]

Birth-parent search advice

Since you gave Mary and Sarah both a 'K' for the last name, does that mean you know they both have the same maiden name?

What are Jane and Linda's Autosomal and X comparison cM results?

Yes, Mary and Sarah have the same maiden name, and are believed to be full sisters. The FF match numbers for Jane and Linda are: cM = 885.06, longest block = 96.67. Is that what you were asking?

Rob

[robdrew7]

Wow, that's a stumper.

Any chance that this new woman's mother was only a 1/2 sister of your mother?
On the father's, rather than their mother's side?

There's no record of a second wife/mother in the family. If the mothers were half sisters, wouldn't the daughters' genetic relationship be more distant?

Rob

[robdrew7]

Rob,

Sorry, but based on the mtDNA results, Linda and your mother can not possibly share the same direct maternal ancestor. Two women directly descended from the same woman will match each other and the woman in their mtDNA haplogroup. I'll leave it to others to address the FF results. Of course, you can always ask the office to recheck the mtDNA and/or FF results.

Vinnie

Thanks, Vinnie. I think that's where we are with this. A more complicated family situation than I had imagined!

Rob

[robdrew7]

How is Linda related to the woman you're researching? She could be a niece through the woman's sister or through the woman's brother.

If she's a niece through the woman's brother, then that's why the mtDNA wouldn't match. Linda has the mtDNA of her own mother, not of her father's mother.

But if Linda is a niece through the woman's sister, then the mtDNA should have matched if the woman's mother and your mother's mother were indeed sisters.

Elise

Hi Elise, This makes sense. It's starting to look like the birth-parent is a brother of Sarah K instead of her sister. I guess it could also be a brother or a sister of Sarah K's husband, couldn't it? Then the link would be through Linda's father's family. Oh, my aching head!

In either case, the next mystery is why the birth-mother gave the name she did - which led us to the right family, but the wrong person. Nice clue!

Rob

[efgen]

Hi Elise, This makes sense. It's starting to look like the birth-parent is a brother of Sarah K instead of her sister. I guess it could also be a brother or a sister of Sarah K's husband, couldn't it? Then the link would be through Linda's father's family. Oh, my aching head!

Hi Rob,

Hmm, I may have misunderstood the generations here. When I originally read your message, I thought you were saying that Linda's aunt's mother was Sarah K (which would mean Sarah K was Linda's grandmother, and that's why I asked whether Linda was related through her mother or father). Did I misunderstand and you meant that Linda's *mother* is Sarah K?

Elise

[JOlson]

Yes, Mary and Sarah have the same maiden name, and are believed to be full sisters. The FF match numbers for Jane and Linda are: cM = 885.06, longest block = 96.67. Is that what you were asking?

Rob

The autosomal cM=885.06 implies a 1st cousin relationship. Zero Mt match tells you they have different Gmothers. I think that an X cM value of about 100 cM could confirm that the connection is through the Gfather. Are these 2 kits loaded on GEDmatch? You can calculate the X cM value there.

[robdrew7]

Hi Rob,

Hmm, I may have misunderstood the generations here. When I originally read your message, I thought you were saying that Linda's aunt's mother was Sarah K (which would mean Sarah K was Linda's grandmother, and that's why I asked whether Linda was related through her mother or father). Did I misunderstand and you meant that Linda's *mother* is Sarah K?

Elise

Hi Elise, Sorry. Yes, Linda's mother is Sarah K. I THOUGHT Jane's mother was Sarah K's sister, Mary K. It's looking like the relationship may be through Sarah K's brother instead.

Rob

[robdrew7]

The autosomal cM=885.06 implies a 1st cousin relationship. Zero Mt match tells you they have different Gmothers. I think that an X cM value of about 100 cM could confirm that the connection is through the Gfather. Are these 2 kits loaded on GEDmatch? You can calculate the X cM value there.

Thanks! I haven't used GEDmatch before, but will look into it.

Rob