Are they first cousins?

[SarahCarroll]

Hello.
I'm hoping someone here may be able to help with a DNA conundrum please?
I'm trying to help a very good friend who's father has recently passed away. Her and her cousin have always been aware that their grandfather was not the man their grandmother was married to. They don't know if they have the same grandfather. Both men clearly had some Asian heritage though. My friends grandmother ran a boarding house in Cardiff, Wales docks area and would have come in contact with many sailors.  My friend and her cousin believe their grandfather was a merchant seaman from Singapore called Osman Ben Ali but it's never been confirmed.  I'll post about him on another board. I'm hoping that if I attach both of their DNA results  and the comparison between them someone may be able to tell me if they are first cousins? Or where I can find out more? Thankyou

[Gadget]

Hi

DNA Painter gives the shared cM range for 1st cousin as 396-1397, with a mean of 866. A shared cM of 365 is suggested to be probably either 1.2 1st cousin or 2nd cousin.

https://dnapainter.com/tools/sharedcmv4

Gadget

[SarahCarroll]

Thankyou.  So would you say it's more likely that they have a different grandfather?

[Gadget]

From what you describe in your first post, I'd say it's probable but, it it were me, I;d want to compare the results using a chromosome browser. Ancestry doesn't provide one but you could upload both sets of DNA results to sites such as Gedmatch or My Heritage.  With MH, you'd need to pay a small fee.

Gadget

[Gadget]

Also, have you checked your shared matches. They might bring up possible leads.

Gadget

[SarahCarroll]

Thankyou. I'll tell her to have a look on Gedmatch. Do you know, by any chance if I could add their DNA results to my Ancestry account? I already have my own there.  I just thought I could look for matches through Ancestry too.

[Gadget]

Ancestry doesn't have a facility to upload results from another site. It would have to be via one of the others  or she could take an Ancestry test.

Gadget

[SarahCarroll]

OK, thanks

[Gadget]

What site does she and her match have their results on?

The advantage pf Ancestry is that it has the largest database. The disadvantage is no chromosome browser