Will DNA testing solve this query?

[BRO64]

Hi all,
I need an insight on this please.Right then I'll try and explain this as best as I can.
Two married couples, we'll call them A and B.The two women in the marriages are sisters.
Couple A have a boy,he's told in later life that it's not his real father.Even though it's never revealed,suspicion points heavily to the husband in couple B as his real father.
Couple B also have a son.The two resulting sons both have daughters who are the only survivors today.
My question is,if the daughters both have a DNA test would it show that they both have the same grandfather from couple B or would the fact that A and B are sisters affect the outcome?
Hope I explained this ok.

[Mike in Cumbria]

I don't think you could solve this just by testing the DNA of the two grand-daughters, for the reason you give.
You would need to find another person related to man B - for example a descendant of one of his siblings. If grand-daughter A shared a good deal of DNA with this person, you could start drawing conclusions.

[BRO64]

Thanks for your reply Mike.
Didn't think it would be that straightforward.It could get awkward if a descendant was found.Having to ask them if they would mind taking a test etc. Perhaps another avenue to explore would be if granddaughter from couple A took the test and put it on one of those databases .A small chance maybe a match may be found with a descendant from the man in couple B.
I'm a bit out of my depth on this one

[Ruskie]

Your idea might be worth a try BRO64.

If they are both willing, I think testing both grandaughters might be more useful than just testing one so you can compare similarities and differences in results. This will also help show you which matches come from the grandmother's side of the family - obviously those who don't match with both grandaughters will come from their father ... Results and matches do vary though and are sometimes not exactly as expected even between siblings.

Good luck.

[BRO64]

Sorry for the late response Ruskie.
As granddaughter from couple B is not even aware of the situation,how do you approach someone after all this time? Could be a sensitive issue.
Perhaps it might be best for granddaughter A to take a test and then take it from there.
Are we allowed to recommend the best test/site on here,or does that contravene advertisement issues?
Many thanks,
BRO64

[Meelystar]

Have you traced the trees of both men in couple A and B? If so I cannot see why testing both female descendants should be dismissed. There may be relatively close shared matches which are both on father B’s side. Some of my DNA matches have been very obvious. It may not give you an answer but equally it could.

[BRO64]

Hi Meelystar,
We know quite a bit about the "suspected" fathers tree  from couple B, just don't know which road to go down.
Any advice welcome,Thank you

[Ruskie]

BRO64, by all means have A take the test first. See what comes of it, then maybe approach B at a later date.

Alternatively, a lot of people give DNA tests as gifts - perhaps this is something either you could do or you could persuade someone closer to her to do. A lot of people who receive DNA tests as gifts I think don't have much interest in the results (which might explain a lot of messages to matches which receive no response). Depending on how you feel about it, you don't have to mention anything to her about your suspicions.

Most people seem to be testing with Ancestry and uploading their raw data to My Heritage and other test companies.

[Maiden Stone]

Alternatively, a lot of people give DNA tests as gifts - perhaps this is something either you could do or you could persuade someone closer to her to do. A lot of people who receive DNA tests as gifts I think don't have much interest in the results (which might explain a lot of messages to matches which receive no response). Depending on how you feel about it, you don't have to mention anything to her about your suspicions.

Caution -  opening can of worms. There may be difficult consequences. You can read about some online.