Another ancestry question- unexpected result

[whataboutbob]

This concerns a relative of mine. Her mother was from Italy, her father had a British German mother ( born in U.K. but all ancestors on family tree of German extraction) and a French father. So on the face of it she should be roughly 50% Italian, 1/4 French and 1/4 German. Her ancestry DNA came back as no French, no German, about 50% Italian and the rest English and Spanish.
My questions are: is it possible to inherit no dna at all from a grandparent? Can German ancestry show up as English eg because there is genetic closeness between German and English? Are the tests that inaccurate or is it possible that eg the British German family tree ( built up via national archives records) is erroneous eg there was an English ancestor there ( the German ancestors immigrated to U.K. in early 19th century). Thanks for any light anyone may be able to shed. I’ll add that her father is most likely her real father because it has matched her up with a cousin of her father’s as a DNA relative.

First port of call - ask the father's cousin what their results showed re country of origin. Presumably they too have French ancestry, so did that show up in their test?

Also look at how often European borders have changed and where THEIR ancestors were from.

Thanks rollingpipe and justilou. To muddy the waters the cousin has no French blood, but he does have German and English ( the ancestry sites tend not to separate out French and German as apparently there’s been so much intermixing between the two nations) . However it would still be worth asking him if he came out with any German blood at all. He’s quite elderly, but I have his contact details.
An uncle did the German family tree, it is 100% German until the 1920s when they started marrying non Germans in the U.K. and France.
Any other ideas as to why someone would find ancestral DNA which is not borne out by the family tree? Is it worth even thinking that one of the British German ancestors got pregnant extra maritally after a dalliance with a Brit?

probably the results are just wrong. a lot of these ancestry testing kits are not much better than chance at telling where you come from.

I'd assume that it is a dodgy test and ignore it.

I have to say that I distrust the Ancestry DNA results. I know someone who did it twice (Different email address only - and got completely different results.)

Yes, it could just be plain wrong.

The Ancestry DNA tests can’t tell you where someone is from - they can only tell if you have genetic markers typically shared by people in a certain area. And it’s very much a matter of chance which genetic markers are passed down and which not.

A friend of mine did one of these tests and found out that half her DNA was totally not what she expected. It turned out that she had been donor conceived, and the father she had grown up with was not her biological father at all. Her parents were never going to tell her and only did so after she questioned them following the DNA test.

It is possible. I have roughly half Scottish (expected!) and a bit of Welsh, meaning nothing from one grandparent!

@azulmariposa, which ethnicity is missing from your DNA? Did you end up with an ethnic heritage you weren't expecting?

Well the Scottish part is pinpointed in the exact area of where my ancestors are from, the welsh part the same.
I was expecting more general English, and some Jewish- which seems to be missing completely.
Going to get a test for my mum, my dad has been tested already.
We found a half-brother for my dad, which we kind of expected, and a few of my first cousins are on there too.

I’m going to get mine done. Potentially it could be English, French , German, Scottish, Welsh and Jewish. But I think only the 1st three will show through.

I know it's not going to be 100% accurate on location, but it is for relatives. I mean my dads brother found out who his dad was after not knowing for 75 years.

I think it's known that the ethnicity assessment is not accurate? Just a bit of fun.

My understanding is that each test takes only a small selected sample of your DNA as it's not feasible to analyse everything. This would mean results could differ from one test to another as they are analysing different segments of your DNA and matching it with different (more) genetic cousins.

Happy to be corrected.

I also understand that you may not have inherited any DNA whatsoever from around a certain generation (5th g grandparents??). But a sibling may have that DNA. It's hit and miss what DNA an individual inherits.

Fascinating business.

I think it’s surprisingly accurate, it gets updated from time to time and whole new weirdly specific regions and groups suddenly appear in the ethnicity estimate.

the ancestry sites tend not to separate out French and German as apparently there’s been so much intermixing between the two nations

ancestry.com has separate regions for France and Germanic Europe

People moved around Europe a lot. One question on another forum was from a Portuguese lady who wondered why her 100% Iberian family gave about 15% English. Then someone pointed out the presence of a great many British, French and Spanish in Portugal during the Napoleonic wars. Mercenaries from the UK were spread from Russia to Spain.