I present here for your information the process that Yanick DEMERS and I follow to identify at which generation a non-paternal Event (NPE) occurred in his line of men.

Recap of the situation:
Yanick DEMERS discovers that he does not possess the  Y chromosome signature of his ancestor alleged at the documentary level, Jean DUMAIS / DEMERS (m: LECOMPTE Miotte, before 1617 / before 1617 Dieppe (Seine-Maritime: 76217 ) (GFAN # 44))

Indeed, a triangulation at http://miroise.org/catalogue/tri0183/ realized by the genealogist Denis BEAUREGARD shows that the signature of Jean DUMAIS / DEMERS belongs to haplogroup R-M269> M343, whereas the signature of Yanick belongs to the haplogroup G-M201.

Although the lineage of Yanick’s fathers has been rigorously documented and goes back to Jean DUMAIS / DEMERS, it is clear that in the line to Yanick there was an interruption of Y-DNA transmission from Jean DUMAIS / DEMERS since Yanick does not have the triangulated signature DUMAIS / DEMERS but that of another line of men.

This interruption of  Y-DNA transmission is called a * Non-Paternal Event * (NPE).
A NPE may occur, for example, following the adoption or silent assimilation of a child as a result of an illegitimate birth to a daughter of the family, a birth that is camouflaged by passing the child as a son of the grandmother, or following an infidelity or when a man adopts a new surname which he later transmits to his descendants.

The comparison of the STR signature of Yanick with those of men belonging to other lines of men reveals some matches that we will possibly explore in the future.
But, for now, it seemed important to determine at which generation this NPE had occurred.

The attached figure shows the kinship relationships that exist in Yanick’s immediate male family environment.



A first test will determine if Grandfather Raoul had the same DNA-Y signature as Yanick.

To this end, we offered a DNA-Y 12 marker to Nicholas, Yanick’s first cousin (1c).
The results show that Nicholas has the same G-M201 signature as Yanick. The STR values ​​of the two signatures are the same and their Y-DNA belongs to the same G-M201 haplogroup that was predicted by FTDNA.

The results of the two first cousins ​​make it possible to triangulate the signature of their grandfather Raoul. Raoul was thus G-M201 like Yanick and Nicholas.
This triangulation allows us to infer that Yanick’s father, as well as his uncle (Nicholas’s father) were also G-M201, since the DNA-Y signature is integrally transmitted from father to son.

We can conclude from this first stage of the research that the NPE occurred either at the level of the grandfather himself (for example, Raoul might have been adopted) or before him, upstream, at his father, the father of his father, & c.

The next step is to try to triangulate the signature of  the great-grandfather of Yanick and Nicholas, namely Philippe DEMERS.

Since Grand-uncle Roland did not accept to have his DNA tested, his son 1c1r (first cousin once removed) will serve as a substitute since he possesses, in principle, the signature of his father Roland and he willingly agreed to be tested.

We anticipate two specific cases with respect to the result of the DNA-Y test on 1c1r:

E1: The Y-DNA signature of 1c1r is the same as that of Yanick.
The triangulation on Philippe will then be considered successful. This will logically imply that the great-grandfather of Yanick and Nicholas was already G-M201 and that his son Roland was also.

E2: The signature of 1c1r is not the same as that of Yannick (or Nicholas).
The triangulation on Philippe is not successful.

This E2 case holds an alternative:
a) The signature of 1c1r is IDENTICAL to the one that has already been triangulated for the ancestor of DUMAIS / DEMERS (at http://miroise.org/catalogue/tri0183/)
The NPE would then have occurred at the level of Grandfather Raoul who does not show the same signature as his father alleged in documentary terms.

b) The signature of 1c1r is DIFFERENT from that which has already been triangulated for the ancestor of DUMAIS / DEMERS (at http://miroise.org/catalogue/tri0183/)
Here several interpretations are possible and it will be necessary to test them (confirm, invalidate) by submitting to DNA tests  other male descendants of the great-grandfather Philippe.


2016 sep 16