Understand my DNA matches

[tarring227]

I have had some unexpected DNA matches through Ancestry. Before I take things any further I would like to understand the results a little more.

Match 1 - with a male: shared DNA 1,875 cM across 35 segments, Longest segment 182 cM. Possible half-brother

Match 2 - with sister of Match 1: shared DNA 1,516 cM across 33 segments, Longest segment 159 cM. Possible half-sister

Match 3 - with son of Match 1: shared DNA 661 cM across 15 segments, Longest segment 124 cM. Possible half-nephew

A little investigation shows that Match 1 was born in Worthing on 19 October 1958. I was born in Worthing on 20 January 1959.

All my close relatives (mother, father & 2 brothers) are all now deceased & I see that the parents of Match 1 are also deceased.

What reliance can I place on the DNA results & if they are accurate would I be right in thinking that I would share the same father as Match 1?

Any thoughts on this would be much appreciated as of course I want to approach Match 1 with sensitivity.

TIA

[LizzieL]

Hello and welcome to Rootschat.
Those high values certainly seem that is one possible relationship to your matches.

Presumably you have discounted uncle/ aunt - niece/ nephew relationship which DNA painter gives as another possibility.

[larkspur]

Not sure this is going to help you at all....My friend has a 2,002 match with her niece and a 1,971 with her half brother. So the niece "scores" higher than her half brother from another mother.

[Carmella]

You could try the "What Are The Odds?" tool on the DNA Painter website - you can experiment placing yourself at different positions in a family tree - it then generates probability scores based on the cM data values entered.

[Biggles50]

Welcome to RC.

Yes, you and match 1 and match 2 could share the same Father.

If your “Parents” had siblings then do any of the siblings have children?

If so then getting them to take a DNA test would be my first priority.

This would confirm which parental side is correct as there is also the possibility that you were an unofficial adoptee.

Keep options open at all times.

I would also look at Shared Match’s.

I would also build a tree with your highest cM as the home person, leave yourself out of the tree.

It is also worth noting that DNA is not inherited exactly, it is a random process and hence whilst the total cM is the same the make up is unique to the individual (identical siblings excluded).  This random process gives the genetic diversity and accounts for the variations in cM between match’s ie like you have with match’s  1&2.

Do take a look on Gedmatch and on My Heritage to see if they are also on these sites, if you can ID them on either do come back and we can advise further.

In any case please do not leave your post open, we would like to know what happens

[tarring227]

Thanks to everyone for their replies - much appreciated and plenty of food for thought.

Both my assumed parents had a sibling each who each had 1 child but again all are now deceased

My 2 brothers (both deceased) each had 2 daughters. The 2 daughters of my middle brother have both taken DNA tests. Ancestry shows them as a Shared Match on my maternal side only

Niece/half-Niece 1 - shared DNA 1,006 cM across 39 segments, Longest segment 83 cM.

Niece/half-Niece 2 - shared DNA 390 cM across 19 segments, Longest segment 44 cM.

From my original message: Matches 1, 2 & 3 all show as Shared Matches on my paternal side

I am reluctantly leaning to the belief that I share my birth mother with at least 1 brother but not my birth father or am I jumping the gun?

[Biggles50]

I would be more interested of your Brother’s Daughters Shared Match’s rather than the Ancestry Maternal assignment initially.

If your DNA “relations” are not a shared matched to the Girls then yes, the Maternal assignment will probably be correct.

The 1006 cM fits the 1/2 niece cM value but the 390 cM is pretty low and DNA Painter shows a more distant relationship.  That said the random inheritance of DNA could be affecting the matching in that she may have inherited more from her Mother of the areas of the genome that are actually tested.

That would steer back to questionable Paternity, but I suggest exploring all possible hypothesis prior to contact.

I would still look at the Paternal Grandparents and in particular if there are any DNA match’s from their siblings descendants.

Talking of contact, do check out Social Media for them and if you find them there is likely to be images that you can compare to your own.

[brigidmac]

I would tend to agree with your conclusion
My nephew shows as being related to both sides for me.

My aunt shows as being from my paternal side
But her test shows me as being related to both of her sides....logic !

Have you looked at the shared matches of the people you mentioned in your original post
Even distant matches can give clues

I suggest colour coding. Eg   red + yellow for surnames of  paternal grandparents match
Blue for Locations green .ethnicity
+A group for everyone who matches your top paternal match


Use filters to look at your paternal matches

Distinct groups will emerge .
 Surnames may not help with descendants if
Illegitimacy or adoption is involved but you may see a pattern  .in places . ethnicity or common ancestors

Good luck