DNA match to 3rd great grandfathers brother

[themonkeymonkey]

I have come up as being very close relative (2nd cousin) to my 3rd great grandfathers brother!   I have no DNA matches to my 3rd great grandfather.  I know that the death certificate of my 3rd great grandfather shows the same father as his brother but would that come up as such a close match.  Getting confused!

[phil57]

Any indications of a specific relationship are just suggestions based on the most probable estimate of a relationship between two individuals at the given length of their DNA match. You need to investigate the match through your own ancestors and those of the match to establish where the common link between you occurs.

If you enter the match length in cM into the DNA painter tool at

https://dnapainter.com/tools/sharedcmv4

it will give a list of possible relationships based on probabilities. The relationship with the highest probability is the most likely, but that doesn't mean it is necessarily the actual relationship between you and your match. Any of the other probabilities are possible, and someone has to fit them, or they wouldn't be included.

[Biggles50]

What do you mean by 3rd Grandfather?

Why I am confused & asking is:-

A 2C or Second Cousin shares at Great Grandparent level.

At Great Great Great Grandparent level the relationship is 4C

The way I read your text the bother or a 3rd Grandfather ie Great Great Great Grandfather would mean the common Grandparent level would be Great Great Great Great Grandparent and at that level the relationship would be 5C

[Heb66]

Hello monkeymonkey,

How many centimorgans is your close DNA match regarding the connection to your 3rd grandfathers brother ?

Warmest regards....Helen.

[Ruskie]

I’m confished too Biggles. 

Monkey, are you saying that you match your 3rd great grandfather’s* brother, but you don’t match your third great grandfather?

If they were brothers, DNA wise you should match with both of them.

Are you thinking that the brother is your ancestor rather than your documented third great grandfather? That is, your third great grandfather and his brother are not siblings?.

*I’m assuming that when you say “third grandfather”, you mean third great grandfather?

[themonkeymonkey]

Ruskie yes sorry i meant my 3rd great grandfather, yes I have matches to the brother which are coming up as 2nd cousins with 261.6‎ cM which is actually one of the largest matches I have in all of my DNA matches.   Would that be about right?  I thought it would have been with my actual 3rd grandfathers line not his brothers if that makes sense.  New to the DNA matching but its giving me loads of matches to the brothers line of his family.  Thanks for everyones help.

[themonkeymonkey]

Phil57 this is what comes up with that tool (something that I will be using a lot of)


Most distant common ancestors

Assuming no pedigree collapse or endogamy, and that you're related in just one way, the furthest back you might need to go to find common ancestors for a match of 261cM is 3rd-Great-Grandparent level or generation 6 on your pedigree chart.
The connection may be closer.

Relationship probabilities (based on stats from The DNA Geek)

New: View these relationships in a tree

    61%
    Half GG-Aunt / Uncle 2C Half 1C1R 1C2R Half GG-Niece / Nephew
    23%
    1C3R † Half 2C 2C1R Half 1C2R
    16%
    Great-Great-Aunt / Uncle Half Great-Aunt / Uncle Half 1C 1C1R Half Great-Niece / Nephew Great-Great-Niece / Nephew

[themonkeymonkey]

Heb66 closest match is 261.6cm.  Many thanks for the help and advice.

[Heb66]

Hi Monkeymonkey,

Just an example ....my son has a confirmed relationship DNA match of 262 centimorgans . She is his grandmother's first cousin.

Thought it may help.

Regards....Helen.