Help with matching segments

[miw]

Hi
Can someone help me please?  If a known relative of my father and a known relative of my mother both match me on the same segment does that mean that there is a link between the two lines of my tree?  I'm wondering if it might be that they match with the two strands of my DNA where one strand is from my father and one from my mother.  I have a few instances of this on the spreadsheet where I compare matches from FtDNA, MyHeritage and Gedmatch.  Here is the strongest example
M S      1   20,080,310   35,081,247
G A T   1   20,431,299   31,088,765

[Carmella]

Hi

There used to be a tool on Gedmatch called "are my parents related" or something like that -
I don't know if it still exists as I've not used Gedmatch myself.

Also, have you investigated if the segments concerned triangulate?  MyHeritage highlights triangulated segments on their chromosome browser for you. There's lots of articles on DNA Triangulation on the web, here's one:

https://thegeneticgenealogist.com/2016/06/19/a-triangulation-intervention/

[miw]

Thank you.
Gedmatch does say that my parents aren't related but I'm not sure how certain results of that tool are.
I will read that article in the morning.
Mary

[miw]

I have read the article and I'm more confused now, to be honest.  I'll have to do some more reading around this.

Thanks again for the link.

[Carmella]

Hi,

So, I've had another think about this and wonder if your matches are on different sides of the same chromosome - so one side is paternal the other maternal - as you've already mentioned.(Unfortunately chromosome browsers do not show a 3D picture to illustrate the 2 sides!)

Rough summary example from my tree -

I match "Vera" on chromosome 15 position 1000 - 4000
I also match "Peter" on chromosome 15 position 1000 - 4500

When I click on "Shared Matches" on MyHeritage, Peter is not on Vera's list & Vera is not on Peter's.

When I put Peter & Vera into the chromosome browser they do not triangulate with each other & me at all.

So either my match with Peter is on my father's side and my match with Vera is on my mother's side or vice versa.  And, Peter & Vera are not related to each other.

There is an article from Roberta Estes that explains this - see the 6th paragraph down:
"Every Chromosome Has Two Sides"

https://dna-explained.com/2013/12/15/one-chromosome-two-sides-no-zipper-icw-and-the-matrix/

[miw]

Thank you Carmella

That article is brilliant and confirms what I was wondering about.  Although I'm still wondering about where the matching segments from a match on Dad's side and a match on Mum's side start or end on exactly the same point.  I might put this further down the list of things to research for now.

Best wishes
Mary