The Fennimore Family of Somerset and Morris Counties New Jersey A DNA Project – A Twist

Where we last left off, I was using DNA Painter to map Gedmatch matches with two known Fennimore descendants. None of the one hundred shared matches were closer than 3rd cousin.  I then turned my attention to 23andMe.  I looked to see if my two known descendants had an obvious kit in 23andMe, but none stood out. Unfortunate but not unexpected. Only six[i] of our shared Gedmatch matches originated in 23andMe so, I decided to scroll through my DNA matches to see if any of the six names had a commonality with the Gedmatch kits.  When I reached page four, something exciting happened; a tester with the “right” surname appeared, and he had opted in for sharing.  My first step was to look at our shared DNA to see if it was consistent with my Gedmatch results. We share 39 centimorgans on chromosome 18, where I have mapped a dozen kits, including the descendant of Louis Fennimore.  The correct surname, and the right matches, I add it to my tracker and start digging into our shared matches in 23andMe, as I did in Gedmatch.

I look at our list, and a familiar surname was at the top, associated with my maternal family. My Fennimore family is on my father’s side, and this was unexpected.  The name is very familiar, and I believe that he is my second cousin’s son.  My great Aunt, his grandmother, was not a Fennimore, and my parents are not remotely related (Gedmatch verified).  I examined the match a little closer:

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23andMe makes this very easy.  I can see that we three do not have shared DNA, we match, but not in the same way. I also look at our relationship, and you can see that there is a large difference between the two.  Even when I put my “2nd cousin” into DNA Painter, it associates the kit with one set of maternal great-grandparents, which I am mapping.  My conclusion is that my cousin’s unrelated paternal line has a far removed match with this test kit or a possible anomaly.  I hadn’t even considered that my paternal and maternal lines could be intertwined, my mother is second generation Irish-German.  My Paternal Grandmother was a mixture of recent British immigration (her mom was born in London), and New Jersey for at least nine generations. My Dad’s father was from New England. I knew that I didn’t have any misaligned parental events in recent generations. Again I lucked out; I could easily resolve this twist.

Do you agree with my analysis?  Have you encountered any DNA conflicts? If so, how did you resolve them?

I’d love to hear from you!

[i] Coakley, Louise. “Tips for using Gedmatch.” Genie1., 2020.

GEDmatch – Tools for DNA and Genealogy Research ©Copyright 2011-2020 by GEDmatch, Inc.
23and Me – © 2020 23andMe, Inc.
DNA Painter – © DNA Painter, 2020

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