Can you use DNA, inlcuding Y DNA, to find the family of an orphaned ancestor? This scenario considers YDNA and autosomal DNA testing for finding the missing family of an Italian orphan.

As part of a Legacy Family Tree Q&A series I did recently, a participant named Mary asked an interesting question:

“I recently found out that my great grandfather was an orphan in Italy. How do I use DNA to find his birth family? Should my brother take a Y-DNA test? If so, can you tell me which test most Italians (or Europeans) use?”

Here are some thoughts for Mary—or anyone else who wants to research an ancestor with unknown origins. Especially in Europe. Let’s consider first Y DNA testing, then autosomal testing.

Y DNA for Unknown or Orphaned Ancestors

Whenever you are looking for news of a man in your family tree, a Y DNA test is always a good idea. Y-DNA just lets you focus on one single line of inheritance (the dad’s dad’s dad’s line, etc), and can often provide a surname when yours has gone “missing.” (If you do know the surname, it can help you connect with the right family by that surname.)

Make sure you have the RIGHT PERSON take the Y DNA test: a genetic male that is a descendant of your great grandfather ONLY through the male line. For Mary’s brother, that would work to have him test if he’s the son of the son of the great-grandfather.

If you want cousin matches with your Y DNA test results (and you do), you only have one choice in a company: FamilyTreeDNA*. You can start with the 37 marker test, as it is usually enough to determine if there is anyone in the database that can help with your question.

With Y DNA matching, you need someone who has 3 or fewer differences from your Y DNA profile if you hope to connect to a common ancestor within the last 200 years.

Autosomal DNA Testing Can Help, Too

This genealogical timeframe (great grandparents) is perfect for autosomal DNA testing, too. Autosomal DNA testing gives you matches from all lines of your family tree (not just the dad’s), back 4-6 generations.

The best testing strategy would be to test anyone who is still around from your parents’ generation (who is also on the “mystery” side of your family tree). Barring that, you and your siblings and any other descendants of your great grandfather should be tested. You especially need second cousins, as they help to make the work of finding your Best Matches easier because the DNA you share comes from your shared great grandfather.

Speaking of Best Matches, when looking for your great grandfather’s parents, it is good to keep in mind what kinds of cousins you would be looking for to help you figure this out. As other descendants of your great grandfather are your 2nd cousins, you would be looking for 3rd cousins. These would be descendants of your ancestor’s siblings. Fourth cousins would also be helpful, as they would be descendants of your ancestor’s first cousins. Keeping this in mind helps you to focus on the right section of your DNA match list. Essentially, you should start by looking for any genetic 3rd cousins to whom you don’t know your relationship.

Where to test? Well, that is a good question. Everywhere is the best answer! AncestryDNA has the largest database, but anecdotally, MyHeritage has a stronger customer base with Europeans. So I would definitely consider both of those companies first, though you can test with AncestryDNA and then transfer to MyHeritage and FamilyTreeDNA.

In any case, you have a very good chance of finding more information about this line using DNA—if not right away, then given time as the number of testers continues to grow.

Help for Finding Your Mystery Ancestor

If you’re trying to find your DNA matches who descend from a specific mystery ancestor of yours, you need my unique quick reference guide, Finding an Ancestor Using Your DNA. The methodology helps genealogists with this specific DNA question—without any extra fuss or steep learning curve.

Show me that Quick Guide!

If you’re interested in YDNA, get started for free with our free YDNA FREE Get Started Course. It will teach you the many ways YDNA might help you answer your questions about your family history. The Get Started Course is an excerpt from our YDNA for Genealogy Course, which takes you deeper into understanding Y-haplogroups and using them in genealogy research (as well as other topics such as YDNA matching, surname project participation, and when to use Big Y).

Check our the YDNA FREE Get Started Course

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