Unexpected DNA matches on My Heritage

[RWLL]

I uploaded my mother's DNA to My Heritage in the hope that it might help identify an unknown great-grandfather on her English side. Her known ancestry is half English (her mother from England), and 1/4 each Scottish and German. Matches confirm what I knew from those regions, common ancestors, etc.

However, she has an unexpectedly high number of matches from Norway and Sweden. The top matches being 62.8 cM, 54.7 cM, 46.8 cM, 45.5 cM, 42.6 cM, etc. She has at least 20 Scandinavian matches above 30 cM and over 40 more matches above 20 cM. Below that level there are obviously many more. I know that My Heritage is very popular in those countries, but these are not just a few small matches.

I’ve looked at the trees for everyone and built out trees for others and, other than very few exceptions, the matches are pure Scandinavian. The shared matches are also from those countries and some smaller North American matches.

Considering the size of some of those closest matches, and the sheer volume of matches, am I crazy for thinking that there must be a legitimate line that must be Scandinavian?

Thanks for any insight!

[Biggles50]

Welcome to the forum.

Worst case scenario for the 62.8cM match is a Common Ancestor at Generation 11 in your Family Tree so the degree of certainly at this level would be highly questionable.

To find a match at the level you seek ie a Great Grandfather then a DNA match c200cM would provide a much higher probability of success.

Often its a waiting game with DNA and the more test companies you use the greater chance of finding a more recent “Cousin” and by uploading the Raw DNA to sites like Gedmatch then even more matches can be found.

My Heritage is not imo the best for UK DNA testing, Ancestry has a much larger client base but alas they do require their own test to be taken.  For me Ancestry has provided much higher cM value matches than My Heritage.

My Heritage gives me a 34% Scandinavian Ethnicity, and quite a few matches, but if their database contains pro rata more testers in these Countries then skewed results can happen, so no you are not crazy.

Keep options open and look for higher cM matches elsewhere.

[hurworth]

How many segments and how large are the segments shared with the 62.8cM match?

I do find at MyHeritage that for some of my relatives Scandinavian matches pop up sharing around 30cM, but they're over several segments of 6 to 8cM, which aren't very reliable.  But if the segments are larger and the SNP count is quite high then they could be meaningful matches.

[shanreagh]

One point also, on the historical side and that is what are the definitions of Scandinavian  and what is the definition of German you are using.  Germany as a country was founded in 1871. 

'The German Empire was founded on January 18, 1871, in the aftermath of three successful wars by the North German state of Prussia. Within a seven-year period Denmark, the Habsburg monarchy, and France were vanquished in short, decisive conflicts.'
http://www.rootschat.com/links/01rup/

I have Danish forebears and think, by their names, that as i get further back there will be ancestors from the current-day Germany in my tree. 
This is around the Schleswig-Holstein area. 
https://en.wikipedia.org/wiki/Denmark%E2%80%93Germany_border

Sweden did also control islands in the Baltic that may have changed to German? 

Anyway the point I am making is that when looking at heritage and genetic matches we need to have some knowledge of the history of the countries.  Of course this match may be the unknown gt grandfather  you are looking for.

[Ruskie]

A seafaring great + Grandfather sounds possible. 

Any high Norwegian/Swedish matches may be related to earlier generations or side shoots of unknown great greadfather.

Consider the female lines where connections are often hiding. 

Agree with shanreagh re the changes in borders.

After all it only takes one person from different lands having children with your English ancestors to introduce that additonal DNA.

I have a known Jewish great great grandmother and on My Heritage get a huge number of Jewish matches. My Heritage is an Israeli company and very popular in those countries hence their (I believe) overrepresentation in my matches.

[hurworth]

I have a known Jewish great great grandmother and on My Heritage get a huge number of Jewish matches. My Heritage is an Israeli company and very popular in those countries hence their (I believe) overrepresentation in my matches.

They are also likely to be overrepresented because they are from an endogamous community, which can make distant matches share more DNA with each other than would be expected for the relationship.

[Ruskie]

I have a known Jewish great great grandmother and on My Heritage get a huge number of Jewish matches. My Heritage is an Israeli company and very popular in those countries hence their (I believe) overrepresentation in my matches.

They are also likely to be overrepresented because they are from an endogamous community, which can make distant matches share more DNA with each other than would be expected for the relationship.

This is true.

[melba_schmelba]

I uploaded my mother's DNA to My Heritage in the hope that it might help identify an unknown great-grandfather on her English side. Her known ancestry is half English (her mother from England), and 1/4 each Scottish and German. Matches confirm what I knew from those regions, common ancestors, etc.

However, she has an unexpectedly high number of matches from Norway and Sweden. The top matches being 62.8 cM, 54.7 cM, 46.8 cM, 45.5 cM, 42.6 cM, etc. She has at least 20 Scandinavian matches above 30 cM and over 40 more matches above 20 cM. Below that level there are obviously many more. I know that My Heritage is very popular in those countries, but these are not just a few small matches.

I’ve looked at the trees for everyone and built out trees for others and, other than very few exceptions, the matches are pure Scandinavian. The shared matches are also from those countries and some smaller North American matches.

Considering the size of some of those closest matches, and the sheer volume of matches, am I crazy for thinking that there must be a legitimate line that must be Scandinavian?

Thanks for any insight!

I think this comes up every week, it's also in the Common Room right at this moment . It is known 'phenomena' of MyHeritage to give Brits unlikely close Scandinavian matches. They are mostly probably either false matches, IBD or IBS. MyHeritage has to use imputation to match between kits, because they switched chips themselves in 2019, the old one only having a fairly small overlap to the new one, and also to allow for uploads from other companies that also use different chips. Someone did a survey of matches below 30cM for a child and their parents, and found a large %, about 1/3 below 24cM were false matches, also larger matches with segments below 12cM were also very unreliable with a high % false.

[Cell]

I uploaded my mother's DNA to My Heritage in the hope that it might help identify an unknown great-grandfather on her English side. Her known ancestry is half English (her mother from England), and 1/4 each Scottish and German. Matches confirm what I knew from those regions, common ancestors, etc.

However, she has an unexpectedly high number of matches from Norway and Sweden. The top matches being 62.8 cM, 54.7 cM, 46.8 cM, 45.5 cM, 42.6 cM, etc. She has at least 20 Scandinavian matches above 30 cM and over 40 more matches above 20 cM. Below that level there are obviously many more. I know that My Heritage is very popular in those countries, but these are not just a few small matches.

I’ve looked at the trees for everyone and built out trees for others and, other than very few exceptions, the matches are pure Scandinavian. The shared matches are also from those countries and some smaller North American matches.

Considering the size of some of those closest matches, and the sheer volume of matches, am I crazy for thinking that there must be a legitimate line that must be Scandinavian?

Thanks for any insight!

Given those substantial Cms and the volume  (" The top matches being 62.8 cM, 54.7 cM, 46.8 cM, 45.5 cM, 42.6 cM, etc"   )
I would say your mum has a Scandnavian ancestor,  and they are  not false matches.

My teen son has a known third great grandfather from Finland (  who was my mother in laws g grandfather). He was a sailor, met a local girl and the rest is history. ( they married, and he settled down in his new homeland in Wales, but many didn't of course)

My son's Scandnavian ( Finnish and Swedish matches mostly) substantial  matches  on My Heritage ( uploaded DNA).are in  the 20s and the high 30s -  36 , 37 ( for example  the highest match is 38cm with the largest segment being  24.3‎ cM )  - which is lower than your mum's matches  ( although my teen son is either one or two generations  below  your mother of course). 
So yes I'd guess your mum has a Scandinavian ancestor ,  given  those cms  compared to my  teenage son's matches  who 100% has a  Finnish  3 great grandfather.
 I'd  also take a  guess that the Scandinavian ancestor is not too far back  from your mother, maybe a second great.

Kind Regards