I am having trouble figuring this out. A 3rd cousin popped up with 117 cMs shared across 6 segments via Ancestry DNA.

She is not a match with my Mom and there is not a common match with my dad's biological family.

What other scenarios might there be?


2 Answers 2



  1. She's related on your Dad's side and you just don't have any close relatives on your Dad's side who DNA tested and share enough DNA with her to reach the threshold to show up as a match, or

  2. You could be related on both your Dad and Mom's side. Both your Dad and Mom passed down shared DNA to you. Your Mom does not have enough shared to reach the threshold that is considered to be a match. But the combined amount you received was enough and was called a match.

  • Thanks lkessler. Agreed, my Dad's side. Appreciate your help and clarity on this subject! Nov 3, 2018 at 1:06

It's hard to tell with AncestryDNA because there is no chromosome browser. If possible, uploading everyone's raw data to Gedmatch and using their browser is the way to go.

This may or may not be a 3rd cousin. If you come from endogamous ethnic groups, a match like that is more likely to be a 4th or 5th cousin. But even if it is a 3rd cousin, that would mean you share great great grandparents. You have 16 of those. 8 lines total (I'm count the route to each couple as 1 line). 4 lines on your dad's side.

Do the relatives on your dad's side who tested cover all 4 lines? You can't say that the match isn't via a line just because there isn't a match with a relative from that line, because the match isn't close enough to be sure there would be matching segments. But it is more likely that your match with this person comes from one of your father's lines that isn't covered by family members who took DNA tests.

  • Thank you Cyn for your reply. I looked further at some matches that have trees and found matches. I agree that they are on my Dads side of the family. Nov 3, 2018 at 1:03
  • Oops, hit add comment on accident. My Dad was adopted and his siblings that i have relationships haven't taken a DNA test. I did have a first cousin pop up on must be his side which was interesting! I'm confused on that connection too. :) Nov 3, 2018 at 1:05

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