DNAPainter and myheritageDNA anomaly - help please

[sugarfizzle]

I have been using DNA painter for a while now, but as I have had limited success in finding confirmed matches anywhere but Ancestry, I have had limited success with it.

Now I have four matches for my husband from the same line, but at different stages.  One is a great niece, one a second cousin, one a third cousin, the last one a fourth cousin, from paper research.

In DNA painter they show up as matches on some segments, as I was painting the latest one in (3rd cousin) I was alerted to the fact that it overlapped 2 other matches (interestingly not with his great niece, with whom he shares 935 cMs​ over 27 segments, largest segment 114.4 cMs).

2nd cousin isn't at myheritage, the other three are. They are not shown as matches to each other at all.  How come?

I must admit to not fully understanding chromosome matching, partly because of such limited experience in finding valid matches to paint in

If DNAPainter can find a match between them, why can't myheritage?

Regards Margaret

[hurworth]

The best way to compare them all would be at Gedmatch where you could do a one-to-one comparison between them.

How big do you think this overlapping segment is?  Is it on a known pile-up region? 

[sugarfizzle]

Hurworth, I haven't had much luck in persuading people to upload to Gedmatch. The second cousin being one exception, which is why I can paint his details into DNAPainter to compare with the other​ two.

You can compare up to 7 matches directly at myheritage.
Here is what it says -
A and B share 27 segments (gt niece)
A and C share 4 segments (3rd cousin)
A and D share 4 segments (4th cousin)

'A and all of the selected matches share no triangulated segments'

Remove great niece, so left with 3rd cousin and 4th cousin.

A and C share 4 segments
A and D share 4 segments

'A and all of the selected matches share no triangulated segments'

Yet DNAPainter picked them up as overlapping straightaway. And I can plainly see that C shares 26.9 cMs and D shares 6.3 cMs at the same place on Chr 2.

Great niece B shares most DNA with 2nd cousin C, who isn't at myheritage, unfortunately.

I now realise that my problem is more with myheritage than DNAPainter, so have modified the Subject title.

Regards Margaret
 

[sugarfizzle]

Does myheritage take note of something else?

These people are all clearly related to my husband through documented paper trails. I cannot see why myheritageDNA doesn't recognise them as shared matches, whilst DNAPainter does.

The group as a whole don't fully triangulate, i.e. all four do not match together in the same place on the same segment anywhere.


Regards Margaret

[familydar]

I have a match whose DNA results are on FTDNA, Gedmatch and Gedmatch genesis.  Only one segment but reasonable size.  The source for the gedmatch and gg segment is ancestry.  I have painted all three and they are all slightly different, but the biggest and very obvious difference is that the GG segment has been split in two, with a big gap in the middle.   Possibly MH are using some sort of similar matching system where they know there's a bit of a fuzzy possibly might possibly might not area in the segment(s) and they're erring on the conservative side.

Just a thought.

Jane :-)

[Carmella]

Another possibility -

Could some of the segments be on different sides of the same chromosome?

(2 sides to every chromosome -  two people would need to match on the same side as well as the same segment of the same chromosome).

[sugarfizzle]

Carmella, myheritage knows no more than I do whether these segments or maternal or paternal. So I don't think that is the reason.

However, I know that they are all maternal matches from paper trail.

Regards Margaret
 

[Mart 'n' Al]

3 useful YouTube links to films about DNAPainter, a presentation from the developer, Jonny Perl (5 minutes) ; one from Blaine Bettinger about its use (40 minutes) ; and an interview with Blaine (10 minutes).

https://m.youtube.com/watch?v=--lRrbazUI4

https://m.youtube.com/watch?v=wyjcJxywTZI&t=2s

https://m.youtube.com/watch?v=unGRx3d-Lw0&t=1s

Martin

[sugarfizzle]

Thanks, Martin, I'll take a look later. Your links invariably prove to be interesting.

However, I think the 'problem' is more with myheritage than DNAPainter, unfortunately.
 

Regards Margaret