An Ancestry/Gedmatch Success Story: Lentz DNA

This story starts with a plain genealogy match – just the tree. Al contacted me last April through Ancestry about our possible Lentz connection. I suggested a DNA test. We went back and forth and saw that our Lentz locations, names, occupations and churches sounded familiar. We decided that we had a common ancestor in John Lentz born 1792. Here a portion of my Lentz web page:


Al descended from William while I descended from Jacob. Where I left off with William Andrew, was about as far back as Al had gotten.

Lentz DNA

In early July I noticed that Al had an AncestryDNA match with my mom. It wasn’t large, but it was there:

This was good news, as my Lentz DNA documentation was sketchier than I thought it should be. Maybe sketchy isn’t the right word, but there were some ambiguities. I had trouble nailing down John Lentz as it appeared that there may have been two of them in the same area.

Here is the connection between Al and my mom:


The Lentz side is in yellow. My previous Lentz DNA testers were also part of the Nicholson family (in orange above), so Al was an important link to the non-Nicholson Lentz side. Al is in the bottom left box.

upload to gedmatch

My next step was to ask Al to upload to gedmatch. Sometimes this step is easy, sometimes not. Al had trouble uploading but just recently, I discovered that he had actually uploaded his results. When I checked the results, there was no match between Al and my mom. I had to lower the thresholds to find the match:


The interesting point here is that I would have never seen Al’s match with my mom at Gedmatch, because their match is below their threshold.

yes, but do we have triangulation?

If Al were to match with another person that matched my mom, we would have a triangulation group (TG) which would make this match all the more solid. Fortunately, one of my mom’s first cousins, once removed also uploaded her 23andme results after some initial problems many months ago. I had to lower the thresholds even further to get her match, but it was right where it needed to be for triangulation:


In order to close the loop, Judy had to match my mom at this location. This was not a problem:


My conclusion is that the TG merges in on John Lentz:


Technically, the match could be with John Lentz or his wife Elisabeth, but we will say John Lentz. Further, I am now able to identify the match on Chromosome 14 between my match and Judy as a Lentz match – or more specifically from my mom’s grandfather Jacob Lentz:


Here is Jacob with bow tie and cigar:


How AncestryDNA and Gedmatch Worked Well Together

AncestryDNA told me I had the match. They also provided a way to get in contact with someone with the same ancestry. However, Ancestry says this about the match:


They thought that Al and my mom would have what I would assume to be a 15% chance of having a recent common ancestor or couple (John Lentz and his wife Elisabeth). That is where Gedmatch came in. If I could show that Al, my mom and someone else triangulated, that should significantly up the odds that there was indeed a common ancestor. Due to Al and Judy uploading to Gedmatch, I found that to be the case.

One Reply to “An Ancestry/Gedmatch Success Story: Lentz DNA”

  1. Al and your Mom matched with 6.7 cMs. But, if Al is a generation younger than your Mom, he has probably been through recombination one more time than your Mom. I.e., if Al’s Mother had tested, Al’s Mother and your Mother could have shared closer to 12 cMs. I like to have a general age of my match to compare apples to apples. Not a scientific approach but just something to factor into the equasion.

Leave a Reply

Your email address will not be published. Required fields are marked *