A Genetic Genealogy Success Story (Finally)

I have figured out my first genetic cousin match after years of collecting and analyzing.

The match is in my maternal grandmother's tree.  This surprised me because I have not been able to trace my grandmother's Irish tree very far back.  I thought my DNA success would be in my father's extensive Colonial American tree.

I noticed this close match in the DNA Relatives feature of my maternal uncle at 23andMe.  After the eight known close relatives, this match immediately followed, matching my uncle 0.87% over five segments.  (In contrast, this match in my mother's DNA Relatives is number 45.)  The match was anonymous, so I sent a request to "share genomes."  The other person, D. J., accepted, enabling me to compare him to my close relatives.  D. J. matched my mother, her half brother, and their first cousin; but not my maternal grandmother's paternal cousins (the O'Donnell side).  I figured the match would be through my maternal grandmother's mother's side (the Preston side).

23andMe
Family Inheritance:  Advanced

My sister and I inherited almost all of the DNA that my mother shares with this cousin.

Parents and grandparents of my maternal grandmother, Jeannette O'Donnell.
Because this mystery cousin matched my mother and her half brother, the match was from Jeannette's tree.
The mystery cousin did not match Jeannette's paternal cousins,
so the match was through Jeannette's mother, Anna Preston.
Family Tree Maker 2012

Next I viewed D. J.'s genetic distant cousins who also shared the matching segments.  23andMe makes available the Ancestry File of people who are sharing genomes with you.  This file contains their genetic matches and the segments where they match.  This provides limited info:  If the match is anonymous, no name is displayed; and if a match has not filled out a survey specific to this file, the person is omitted entirely.

Ancestry Finder matches of cousin D. J. from 23andMe

I was expecting Irish matches.  These look like my mother's paternal matches, not maternal.  If none of her close maternal relatives had tested, I would have erroneously classified D. J. as a paternal match of my mother.

Next I looked at D. J.'s Ancestry Composition.

Ancestry Composition of cousin D. J. at 23andMe

D. J. is approximately half Ashkenazi.  This bumps his smaller matches (in this case, Irish) out of the picture almost entirely.  My uncle is not Ashkenazi.  D. J. placed at the top of his unknown matches.

D. J. answered my inquiry.  The focus would be on his father's tree.  D. J.'s paternal grandfather was Norwegian and his paternal grandmother was of Irish heritage, born in Bayonne, New Jersey in 1922; last name Beirne, pronounced Burn.

Irish and Bayonne, New Jersey was a great place to look for the common ancestors!

Notice that he did not give me a surname that matched any of my ancestors.  Because I had traced my family tree up and then across and back down, I knew Beirne.

Obituary of my great grandmother, Anna Preston, wife of Frank O'Donnell.
Her sister, "Mrs Thomas Burns," is mentioned.  This is Hannah.

This was a difficult family to find because the name was spelled Byrne or Burn in indexes.  I figured it must have sounded like Burn.  My great grandmother's sister, Hannah Preston, married Thomas Beirne in Bayonne in 1911.

Copied at New Jersey State Archives in Trenton by J Lutter

I had found two children for this couple:  Mary, born 1912, and William, born 1915.

Copied at New Jersey State Archives in Trenton by J Lutter

Copied at New Jersey State Archives in Trenton by J Lutter

I guessed that D. J.'s paternal grandmother was Mary Beirne.  He replied that her name was Regina, born 1922.  I had come across Regina Beirne.  She was the contact person on Thomas Beirne's registration for the draft of World War II.  I had not determined how she was related.

Draft registration, 1942
Ancestry.com

If Regina was a daughter of Hannah Preston and Thomas Beirne, how did I miss her?  I returned to the 1930 census to find Regina.  If she was born in 1922, I should have found her with her family in 1930.

Line 46 is Regina Bierne.
1930 United States Federal Census
10 West 17th Street, Bayonne, Hudson County, New Jersey
ED 197, page 6A (Ancestry.com)

Do you see how I missed Regina?  She is listed with the prior Aiello family.

I checked my grandmother's family notes and sure enough, she had written "2 girls & 1 boy" for Hannah.

Family notes of Jody's grandmother

This makes D. J. my third cousin!  We share a pair of great great grandparents:  John David Preston, born about 1857 in Pine Plains, Dutchess County, New York, and Bridget Sheehey, born about 1857 in Ireland.

And here are our great grandmothers, Hannah and Anna Preston, sisters, in the household of their parents in the 1900 census.

Household of John D Preston
1900 United States Federal Census
Independence, Warren County, New Jersey
ED 190, page 7B (Ancestry.com)

Back to the DNA:  My sister and I match this third cousin 0.56% over three segments.  This is about half the DNA that my father and his siblings share with their third cousin.  D. J. is a second cousin, once removed to my mother, her brother, and their first cousin.

By comparing other genetic matches to this known third cousin, I can isolate some matches to the Preston branch of my mother's family tree.

For further studies, D. J.'s father could be tested.  This will show us additional common Preston segments, but will also reveal many more Preston genetic matches that are missed in D. J.'s own account because of his mother's Ashkenazi heritage.