Tuesday, May 31, 2011

FTDNA's Family Finder: My New Illumina Chip Results and Investigating a "Close" Match

I finally received my updated Family Finder results with the new Illumina chip from FTDNA. There was a problem with my sample, so it took much longer than expected. I have been excitedly investigating my new and improved match list.

With FTDNA's original Affymetrix chip I had 54 total Family Finder matches. I now have 59 total matches with the new Illumina chip (including some new customers). Between the two chips, there are only 22 matches in common and 32 matches from my old list are gone completely. On the Affy chip I had three matches under the "Close to Immediate" match filter. I now have four using that filter on the Illumina chip. One is the same. One is a brand new participant. One was previously listed as 4th to distant and one was previously listed as 5th to distant. Of the old Affy "Close and Immediate" matches, one is now listed as a 4th to distant and one is completely gone from my match list.

I was surprised and happy to see the brand new "close" match.  This is my first 3rd cousin prediction on Family Finder (range 2nd - 4th). We have 2 blocks of DNA in common. The one on Chromosome 5 is 17.67 cMs and on Chromosome 18 we share 5.63 cMs. My match agreed to upload her raw data file to GEDmatch, so I could compare her to my mother's 23andMe file. This allowed me to determine that they match on longer stretches of the same spots: Chr 5 = 21.9 cM and Chr 18= 9.4 cMs. I share ~ .315% of DNA with her and my mother shares ~.42%. Since a 3rd cousin will share on average .781% and a 4th cousin .195%, this one appears to fall somewhere around a 3rd cousin once removed.  (See expected percentages here.)

Yellow bars are where I match my new predicted 3rd cousin

We confirmed that we do not have any second or third great grandparents in common, so the match must be further back than predicted. We haven't been able to figure out our exact connection, but we have narrowed down our match to a very specific area and branch of our trees. Her fifth great grandmother, "Catherine" married Johannes (John) Long. Some believe Catherine was a Kinard, but she has long been rumored to have been a Roderick. If so, this would mean that she is related to my third great grandmother Susannah Roderick, since all in the area with that surname were descended from the same immigrant Rothrock family. Catherine is the right age to be the sister of Susannah's father Daniel Roderick. If this is correct, then their parents Johann George Rothrock and Elizabeth Roemig would be my match's sixth great grandparents and my fifth great grandparents.

My match also theorized that Susannah's mother Elizabeth Long is the sister of Johannes Long who married Catherine. If indeed Johannes Long and Elizabeth Long are siblings, then their parents (unknown) are her 7th great grandparents and my 5th. This would make us double 6th cousins once and twice removed.

This double cousinship could account for the surprising amount of DNA that we have in common. Presently, this is just a theory but, certainly, our close match lends credence to Catherine, indeed, being a Roderick/Rothrock. These Pennsylvania Dutch families all lived in Bucks and Berks Counties, Pennsylvania, intermarried and traveled together to (Ross County) Ohio and Illinois. They may have even known each other back in Germany. Although, I am not totally convinced that we have determined our exact connection, I am confident that we have pinpointed the correct family branches and geography. 

There is also a possibility that we have a connection through Susannah Roderick's husband, my brickwall Asa Travis. Since these families intermarried frequently, it is conceivable that his parents were also related to one of the Pennsylvania Dutch families traveling together. There is little doubt that multiple common ancestors and, likely, cousin intermarriages account for our "close" match. I will be keeping watch for overlapping matches that may help us to narrow down the surnames involved in these connections.
[Disclosure - My company StudioINTV has an existing production agreement with FTDNA that has no bearing on the opinions I express. I also receive a small commission from FTDNA on non-sale orders through my affiliate link, which I use to fund DNA tests. I receive no other compensation in relation to any of the companies or products referenced in my blog.]


  1. Looking forward to meeting you in person at Jamboree! We can talk DNA :)

    Luxegen Genealogy

  2. I just got the results from my Family Finder test - a known 3rd cousin also tested - we are related through our Perry/Jones/Roberts/Owen Welsh line. Our ancestors settled in Oneida and Herkimer counties in NY in the mid-1800's.

    I had my cousin send me his results (he had 89 matches) and I compared them to my 172 matches. My thinking was any that we had in common would also be related through our Welsh line.

    We did not have one match in common... We do match each other (so at least we know the test works) - does this mean that none of the other matches are from our Welsh line? I didn't want to jump to conclusions since I know very little about DNA.