As an aside ...
I am "Tagging" this (General) 'Question' of yours in this "Community.FamilySearch" Forum, to two (x2) specific 'Groups' in the Forum being:
(1) "Genetic Genealogy Research"; and,
(2) "Genealogy and the Y Chromosome",
in the hope that, the members of those groups may be able to answer/assist you.
Both, those Groups, are "Public", which you can join, if you wish.
@Genetic Genealogy Research
@Genealogy and the Y Chromosome
Regarding DNA ...
I just thought these may also help ...
Here is a "Knowledge Article" in 'FamilySrach':
Using DNA in family history research
Here are some helpful articles and lessons regarding DNA found in 'FamilySearch' ...
DNA testing. What is it, and how can you benefit from it?
Through the aforementioned ...
... Which DNA test options are available?
... Already taken a test? Next steps?
... FAQ / Terminology
DNA: AN INTRODUCTION TO GENETIC GENEALOGY, 6 LESSONS
DNA: An Introduction to Genetic Genealogy
DNA: I'VE TESTED, NOW WHAT?, 6 LESSONS
GeneTech: YDNA Solutions to Common Genealogical Problems
Any children you might have received half of your DNA. Present or future grandchildren would have a quarter or less. That halfing continues with each generation. By the time you get to seven generations -- about the same relationship to your Italian forebear, there's very little left, if any. What *might* have been sequenced could easily have no identified markers specific to Italians. Typically speaking, seven generations is the max one can expect.
@MichaelHCooley MichaelHCooley Thanks so much for that understanding. There are sources in the tree connecting each generation between me and that grandmother, so I figured it must be correct and there must be some explanation, but I had no idea what it was. That's very helpful.
And @Brett . Thank you for your guidance with all those great resources!
You will probably be interested is this RootsTech presentation on exactly this topic:
Here is another interesting explanation for what you are seeing:
with so many "greats" in yoru connnection to her - you have so minmal an amount of DNA from her that it could very well be non detectable.
Also as others poiunt out - we do NOT inherit DNA on a perfect percentage basis - based on our pedigree - rather it is based on chance - in other words at any level of descent the amount of DNA you inherit is not the same from all the ancestors at that level.
As an example - you have 4 grandparents - but that DOES NOT mean you have inherited precisely 25% DNA from each - because it was based on a random selection. You could have inherited 40% from one an 10% from another. - and thats just at the grandparent level.
Depending on the group of Italians, it can be one of the harder ones to pick out via ethnicity. I am 25% Italian, and have never shown as more than 8% on any test, usually lower. Having traced the Italian YDNA line, I find that my ancestor was a migrant into Italy (some 800 years ago, admittedly.) The path those ancestors took led them from as far north as Northern Ireland, down through France and into Italy. (Assuming SNP tracking can be taken as accurate.) Assuming that my male line ancestors did not travel this route alone, but instead with families, it is conceivable that the region in Pescara where my ancestors ended up may well be settled by people of quite different genetic background than other parts of Italy.
When ethnicity estimates are computed they are comparing your DNA to their pool of people that they have classified as Italian. If that pool doesn't include all of the diverse peoples who make up Italy in the modern age, then there won't be matches. Each company is always looking to expand their reference populations, and I suspect they will eventually have a more diverse picture of what markers represent "Italian."
In the end, I have plenty of DNA matches to support my Italian heritage, and I find that much more revealing and useful, than the ethnicity estimate.
Yeh - there are various issues related to Ethnic DNA tests that many people get confused about - and many DNA companies often mis-represent.
The fact that you have X% DNA that is Italian - doesnt mean that it should magically match your ethnicity based on where your ancestors lived. (where they lived - didnt determine their DNA in the first place)
Most DNA tests - dont really reflect any sort of date/time factor . . . When in the past - did these percentages reflect where your ancestors lived? 100 years ago, 500 years ago, 1000 years ago?
Most DNA tests don't reflect migration patterns across hundreds of years
Many people dont realize - Your DNA is not being matched to people who lived hundreds of years ago. It is being matched with people who are currently living.
You do NOT inherit the DNA of all of your ancestors in equal proportion
(Dont expect your paper pedigree to match your DNA test perfectly or even near perfectly)
Ancestor DNA is inherited randomly.
One thing that no-one has mentioned so far, is that the tree information that you are seeing in your branch of the FamilySearch FamilyTree may just plain be wrong! There could be some misalignments in the ancestry or missing relatives in that area. This frequently occurs.
You shouldn't view parts of the FSFT as truth until you have actually vetted the data there for yourself. There are a LOT of incorrect sections of the tree that still need to be fixed.