Wednesday, September 13, 2017

Comparing Autosomal DNA Ethnicity Results

I've just started reviewing our MyHeritage DNA ethnicity results. I decided to compare the results again between all of the companies, plus add the new results from MyHeritage. My mother Edna Forgey-Kapple tested with 23andMe, Family Tree DNA, AncestryDNA, and her raw data was uploaded to MyHeritage.
Examining my mother's known ethnic heritage I was able to breakdown her father Charles Forgey's ethnicity. He was mainly Scottish and German. He may also have had some English ancestry, but I have not been able to make that connection.
I was not able to breakdown her mother Graciela Del Castillo's ethnicity. Nicaraguans have a high percentage of Iberian and Native American ancestry, with a smaller percentage of African. It's been difficult for me to trace our family back in Nicaragua beyond the late 1700's. The surnames I have so far are all Spanish.

Here are the percentages from MyHeritage DNA

44.10% British/ Irish/ Scottish seems to be on the high side since my mother also has a possible 12% German ethnicity on her father's side? It's possible she received more of the British/Scottish DNA from ancestors? We inherit differing amounts of DNA from our ancestors, the amount shared with distant ancestors is small, and sometimes can't be detected at all. My mother does match many German line cousins on her Roller line. Not as many on her German Urmey line, which may be the reason for the high British number? Iberian seems too low considering my mother's Spanish surnamed ancestors such as Del Castillo, Garcia, and Granizo. My mother has many Nicaraguan matches with Spanish surnames also. The Native American result of 19% is the highest from all of the companies, and I believe it's too high. 

The East European number is way too high. I suppose this covers Germany also? Although most of it is said to be Balkan. The Balkan ancestry would appear to be completely wrong? 

Family Tree DNA misses all of my mother's British/Scottish ancestry. Instead they assign most of her European DNA to Western Europe? According to their map Western Europe covers continental Europe only. It does cover Germany, but my mom isn't that German. This is a big miss. I would guess the 6% Eastern  Europe is German too? Way too much continental European. The Native American result could be correct? They completely miss my mother's Southern European. This result doesn't reflect her ethnic heritage well at all.

Ancestry DNA gives my mother 40% Great Britain and 10% Ireland. This 50% would have to be assigned to her father, leaving no room for German. There really isn't any room anywhere in these results for her German ethnicity. Like I said before she does have many German related matches, so she evidently did inherit that DNA. Not sure if the Scandinavian relates to the German? My mother has no known Scandinavian ancestry. If she did it would be too far back to show up as 4%. 

I give Ancestry DNA credit for finding Iberian DNA. However the Italian is likely wrong. She doesn't have a high percentage of Italian matches either. She does have a high percentage of Nicaraguan matches with Spanish surnames. Our known Nicaraguan surnames are all Spanish. My grandfather was positively not Italian. 

Looking at the 23andMe result the British & Irish seems low? I would think this would be at least 38%? Although it's possible my mother may have received a higher percentage of DNA from her German ancestors? There is a 7.80% Broadly Northwestern European number, which could reflect either German or British ancestry, or a little of both? There is also a Broadly European result of 6.10%, which could trace to anywhere? There is also an unassigned amount of DNA. The 34% is close enough for me however.

I'm very happy with the high Iberian percentage number here. It makes more sense than the results from the other companies, considering her Spanish family surnames, and her many matches with Spanish surnames. There is an unassigned Southern European 10%. Could that be Italian? I doubt it. It may reflect ancient shared Southern European ethnicity that came down through the generations?

No Scandinavian in these results also makes sense.

Which results best reflect my mother's heritage? 
23andMe's results best reflect her heritage. I have a caveat to this. 23andMe phases results if at least one parent and child tests with them. Both the parent and child's results change due to phasing. My mother and I both tested, and these results are phased.  The unphased ethnicity results look a lot like the other companies, but I would say are still slightly better.

You can adjust the results at both 23andMe, and AncestryDNA. 23andMe allows you to adjust based on confidence level. AncestryDNA allows you to adjust based on a possible percentage range. These adjustments aren't helpful for those who don't already know their ethnicity. 

The take away for me is phasing results with parents and children improves the accuracy of ethnicity results. 


Annette said...

I do have a well documented tree on my Grandfather Charles Forgey's side. My Grandmother was Nicaraguan. Much of her family had been in Nicaragua back to the 1600's. I don't have all of the documentation I would like, but my Del Castillo Great-Great Grandfather was President of Nicaragua. His family history had been researched. I have not seen all of the documentation.

Annette said...

Because my ancestor was President of Nicaragua and came from a prominent family someone did some research and said he found evidence we descend from a Governor of Costa Rica in the 17th Century.

Annette said...

23andMe provided us with a chromosome map of our Ethnic DNA. The Native American does align with our Nicaraguan matches. The Southern European does align with our Nicaraguan matches. I did that analysis in previous blog posts.