A Shared Ancestry Hint of a French Canadian 8th Cousin and Visual Mapping

Recently I have been looking at my wife’s French Canadian Pouliot ancestry and DNA. My thought has been to find a Shared Ancestor Hint (SAH) at AncestryDNA. Then if the person in the Ancestry hint has uploaded their results to Gedmatch, I would be able to analyze those results. In this case, I would like to check using visual phasing to determine whether the match is on the Pouliot line or another line.

Here is the SAH:

Lorraine is my wife’s paternal Aunt. Here is what the DNA looks like at AncestryDNA:

Here is how the match looks like at At Gedmatch,

Actually, based on this person’s email, there are 2 matches. This is the Ancestry one. The other test was at 23andme. They are likely the same person. This AncestryDNA match got higher results perhaps due to the comparison within the same company.

The Goal: Compare Gedmatch, AncestryDNA and Visual Mapping

My goal as stated above is to map one or more of the matching Chromosomes to see if the match along the Pouliot line is likely. I do have two Pouliot 2nd cousins to Aunt Lorraine which will help. It would make sense to map the Chromosomes where they match Aunt Lorraine. Here is how Fred, who is a Pouliot 2nd cousin to Lorraine matches Lorraine on Chromosomes 4:

1. Richard, my father in law
2. Richard’s sister Lorraine
3. Richard’s sister Virginia

Now To Visually Map Richard, Lorraine and Virginia On Chromosome 4

The good news is that there is a lot of Pouliot DNA for mapping this Chromosome. The bad news is that the original Chromosome match between Ann and Lorraine was fairly small.

First I compare the 3 siblings using the Gedmatch Chromosome Browser:

In the image above, I’ve added the crossovers and the approximate locations on the Chromosome where they occur. There are a lot of crossovers bunched up on the right side. Next I assign the crossovers to a particular sibling. Note that I added two crossovers that I missed in the previous image:

• Virginia has 109 crossovers
• Richard has 3
• Lorraine has 4 for a total of 17 crossovers. I have a question mark my Lorraine’s last crossover as I’m not sure if there is one there or not.

Next I map the 3 siblings based on crossover, Fully Identical Regions (FIRs in green), Half Identical Regions (HIRs in yellow) and the places where the siblings don’t match in red.

I’ll start in the middle of the Chromosome where Lorraine and Virginia have a FIR going over two segments (before positions 120):

This gets us started. The DNA that these 3 siblings inherited from two of their same grandparents are represented by green and purple and extend to each of their crossover lines. Next, I look for other FIRs or places where the siblings don’t match. For example, Richard and Virginia don’t match between 59 and 84, so I’ll add two new colors to Virginia, to show the DNA she got from the other two grandparents.

Here it looks like I’m stuck for now:

Now I add a HIR. Our Gedmatch match between Lorraine and Ann was between 33 and 40, so I’ll add one for Lorraine there.

I did this by arbitrarily extending one of Lorraine’s colors to the left and choosing another color to add so Lorraine and Richard would be HIR between 31 and 84. Then I extended those colors to the left as Lorraine had no crossovers on the left side of the Chromosome. Based on this HIR, I can fill in some more on the left had side:

Now I have a lot of the left side of Chromosome 4 mapped out. I also have Fred who is a second cousin on the Pouliot side. I’ll mush all the information together and then try to figure out what color Pouliot is:

Here I’m leaning toward a purple Pouliot. The reason is that Richard has a purple segment (and Pouliot match) from 4 to 14. Richard, Lorraine and Virginia match Fred from 102-126, but Richard may not be mapped in that area yet. However, Lorraine and Virginia have purple in that segment. In addition, I don’t have positions for the two crossovers between 95 and 120. I can get those from Gedmatch by comparing Richard and Virginia’s FIR at full resolution:

The FIR starts a little after 100M and ends at about 106.5. Those two positions numbers define the two crossovers between 95 and 120. That also confirms that Pouliot is purple. This defines a grandparent and the maternal and paternal sides of the Chromosome as Pouliot is on the maternal side for these three siblings. It also defines the other maternal grandparent (LeFevre) as being the red or maroon color.

Next, I can fill in all the other Pouliot sections provided by these 3 siblings’ Pouliot cousin Fred:

A few notes on the mapping:

• Virginia didn’t match Pouliot from 4-14 where Richard did so she gets a LeFevre segment there.
• Virginia also does not match Pouliot from 120 to 135 where her siblings do match Pouliot. So I give her another LeFevre segment there.
• Virginia starts matching Pouliot again at 172. This points out a crossover location that I mislabeled previously as 177. Corrected above.
• There is still a few small segments on the right that I haven’t filled in for Virginia and Richard.

Some additional adjustments

A close look shows that between 180 and 185, Lorraine and Richard don’t match. In order to meet the FIRs, HIRs, and no-matches on the right hand side, I came up with this:

I’m not sure if this is totally right on the right hand side, but it seems close. I show Virginia as having nine maternal segments which seems quite unusual. I would like to point out that the match on Chromomse 4 between Lorraine and Ann. Ann did not match Virginia or Richard on Chromosome 4. Those results (and lack of results) are consistent with the mapping above.

Back to the Original Match Between Lorraine and Ann

A big part of this Blog was to determine whether Lorraine’s small Chromosome 4 match with Ann was on a Pouliot segment. After all that mapping, I would say that the match could not have come through Lorraine’s Pouliot side. The largest LeFevre segment between the three siblings belongs to Lorraine between 0 and 95M.

From the above analysis, I made conclude:

• The 8.6 cM match between Ann and Lorraine is did not come down to Lorraine through the Pouliot side
• The match is either by chance or on the LeFevre side. There are 15 names in common between Ann and Lorraine. They are all French Canadian names. My assumption would be that I could rule out a DNA match on the paternal (Irish) side.
• Ann and Lorraine still have matches on 3 other chromosomes.

Summary and Conclusion

• I was not surprised that this match did not match on the Pouliot side given the inter-relatedness of French Canadian genealogy
• It was possible that this shared match on Chromosome 4 could have been from the Pouliot side, but it wasn’t.
• It is best to not assume that a Shared Ancestor Hint and the shared DNA match go back to the same shared ancestor(s)
• I need to build out these French Canadian lines more at Ancestry
• The best match between Ann and Lorraine was on Chromosome 19. However, there were no 2nd cousin Pouliot matches on that Chromosome.
• This Blog satisfied my curiosity on at least one part of the match between Lorraine and Ann and got me to map out Chromosome 4 for these 3 siblings