RootsChat.Com

General => Ancestral Family Tree DNA Testing => Topic started by: ChrissieL on Thursday 03 October 24 13:35 BST (UK)

Title: Second cousin DNA match?
Post by: ChrissieL on Thursday 03 October 24 13:35 BST (UK)
RF and CR are second cousins.  RF's grand mother and CR's grandfather were brother and sister.
RF and CR share 39cM on their DNA match.  This seems a low number for second cousins.
What do the DNA experts out there think?

Many thanks
Chris
Title: Re: Second cousin DNA match?
Post by: Rufous Treecreeper on Thursday 03 October 24 13:59 BST (UK)
It seems low to me but I’m no expert.
I checked my and my 4 siblings range to a 2nd cousin and it was from 281 to 376cM.
Another 2nd cousin ranges from 146 to 282cMs.
Title: Re: Second cousin DNA match?
Post by: Gadget on Thursday 03 October 24 14:26 BST (UK)
A quick scan of some 2nd cousins' matches gives 340,  292  and 210

However, Painter gives range as 41 - 592   https://dnapainter.com/tools/sharedcmv4


Gadget
Title: Re: Second cousin DNA match?
Post by: ChrissieL on Thursday 03 October 24 14:30 BST (UK)
Thank you for that....quite a big range then, so, although it seems a small number it is possible

Chris
Title: Re: Second cousin DNA match?
Post by: Gadget on Thursday 03 October 24 14:37 BST (UK)
It would be worth doing some cross checking of their shared cMs with other close relatives if possible.
Title: Re: Second cousin DNA match?
Post by: ChrissieL on Thursday 03 October 24 14:40 BST (UK)
It would be worth doing some cross checking of their shared cMs with other close relatives if possible.

Yes, thank you for the suggestion, I will have a look at that. It's not vitally important but it just seemed a low number compared with other second cousin matches
Title: Re: Second cousin DNA match?
Post by: haliared on Thursday 03 October 24 14:50 BST (UK)
Different sites and tests give different cM amounts, they use differing ranges.
How do you know what they share with each other?
Title: Re: Second cousin DNA match?
Post by: Gadget on Thursday 03 October 24 15:03 BST (UK)
Different sites and tests give different cM amounts, they use differing ranges.

See :

https://dnapainter.com/tools/sharedcmv4

As referenced previously.
Title: Re: Second cousin DNA match?
Post by: haliared on Thursday 03 October 24 15:05 BST (UK)
Different sites and tests give different cM amounts, they use differing ranges.

See :

https://dnapainter.com/tools/sharedcmv4

As referenced previously.

That link doesn't show the different sites, just the range.

Found the link to the different sites part, posted below:

https://dnapainter.com/tools
Title: Re: Second cousin DNA match?
Post by: Gadget on Thursday 03 October 24 15:10 BST (UK)
The OP is using the same site for the results - also  DNA painter gives a range  which would cover various different sites.



Title: Re: Second cousin DNA match?
Post by: haliared on Thursday 03 October 24 15:12 BST (UK)
How do you know that? What am I missing? I am only trying to help.
Title: Re: Second cousin DNA match?
Post by: Gadget on Thursday 03 October 24 15:14 BST (UK)
See info, extreme left - it covers various tests

https://dnapainter.com/tools
Title: Re: Second cousin DNA match?
Post by: Gadget on Thursday 03 October 24 15:16 BST (UK)
Chrissie states in the first post that

Quote
RF and CR share 39cM on their DNA match
Title: Re: Second cousin DNA match?
Post by: haliared on Thursday 03 October 24 15:17 BST (UK)
That is not the same as when I clicked on the first link you posted.
Title: Re: Second cousin DNA match?
Post by: haliared on Thursday 03 October 24 15:17 BST (UK)
Chrissie states in the first post that

Quote
RF and CR share 39cM on their DNA match

Where did they get that from is what I was asking. Why are you jumping on my replies when I am only trying to help?
Title: Re: Second cousin DNA match?
Post by: ChrissieL on Thursday 03 October 24 15:21 BST (UK)
The shared amounts were taken from the Ancestry site

Chris
Title: Re: Second cousin DNA match?
Post by: haliared on Thursday 03 October 24 15:43 BST (UK)
The shared amounts were taken from the Ancestry site

Chris

Thank you Chris, do you have ProTools and that is how you know they share that amount with each other? I am asking because my Ancestry matches only come up with the amount they share with me and not with each other as I don't have ProTools so I wanted to know if I was missing something with my matches!
Title: Re: Second cousin DNA match?
Post by: ChrissieL on Thursday 03 October 24 15:49 BST (UK)
No I don't have Pro Tools.  I manage RF's account so I can see that he shares 39 cM with CR. I can't see the numbers that CR shares with anyone else. 

Chris
Title: Re: Second cousin DNA match?
Post by: Glen in Tinsel Kni on Thursday 03 October 24 16:20 BST (UK)
 DNA Geeks say 2c is possible at 39cM though the probability is so small it's very unlikely.  Dna painter haven't had a submission below 41. Personally I'd be comparing the shared matches they have with each other, if one doesn't match a group the other has or one has a mystery group of matches that's unique to them it throws doubt on the papertrail they have. That may not be the case but I'd suggest investigating the possibility just to be sur.

Both of my parents have a bullet proof set of certs and I ignored the obvious clues for a while but finally target tested a couple of first cousins, those tests were definitive and showed both my parents are NPE's and those first cousins are actually half 1c's. There must have been a permanent breeze around my granny's houses 100 years ago from the neighbours curtains twitching   :)
Title: Re: Second cousin DNA match?
Post by: Gadget on Thursday 03 October 24 16:44 BST (UK)
Chrissie states in the first post that

Quote
RF and CR share 39cM on their DNA match

Where did they get that from is what I was asking. Why are you jumping on my replies when I am only trying to help?

I wasn't but you seemed to be a little muddled.
Title: Re: Second cousin DNA match?
Post by: Gadget on Thursday 03 October 24 16:46 BST (UK)
Re ProTools  - it's worth getting them for a short while as it helps with some of the 'odd' ones.
Title: Re: Second cousin DNA match?
Post by: ChrissieL on Thursday 03 October 24 16:49 BST (UK)
Re ProTools  - it's worth getting them for a short while as it helps with some of the 'odd' ones.

Yes I think I might do that. I'll make a note of any odd ones and maybe subscribe for a month if that's an option
Title: Re: Second cousin DNA match?
Post by: Biggles50 on Thursday 03 October 24 21:15 BST (UK)
39 cM between them does not make sense and the 2C relationship is probably very unlikely.

Certainly as advised, subscribe to Pro Tools and compare the Shared Matches.

Also consider that they may not be full Cousins
Title: Re: Second cousin DNA match?
Post by: ChrissieL on Thursday 03 October 24 22:16 BST (UK)
Thank you everyone for your help, your suggestions and advice. I may investigate this further at a later date but I think for now I will just put it on the pending pile  :)
Thanks once again

Chris