DNA Word Problem
October 26, 2014 6:09 PM   Subscribe

Family legend has it that our ancestors were Separdic Jews who fled Spain for Italy during the inquisition. My great-grandparents definitely came to Ellis Island from Italy, but they are as far back as we can trace. I am interested in seeing if this is true. I need help figuring out who should get tested and what test they should take. Family tree details inside.

Gen 1. Woman - deceased
Gen 2. Man - son of gen 1. Elderly, may not want to be tested.
Gen 3. Woman - adult daughter of gen 2. (This is me.)
Gen 4. Man - adult son of gen 3.

So grandmother, father, me and son. W, M, W, M.

Can my son or I be tested for my grandmother's ancestry and what is the name of the test we should take?
posted by 1066 to Science & Nature (7 answers total)
There are a number of genetic tests available on the market that will tell you from what geographic region your DNA most likely originated. I took it last year and confirmed my family history while discovering a curious and previously unknown connection to Mali! The one I took was from Ancestry.com but there are others out there. A quick Google search would point you to the one best for you.
posted by Jamesonian at 6:42 PM on October 26, 2014

Best answer: Sorry to be the bearer of bad news, but I think you're unlikely to get more insight into your family history from DNA.

There are three different kinds of DNA you can look at for determining ancestry: mtDNA, from your mitochondria, Y-DNA, from men's Y chromosomes, and autosomal DNA, from your 22 non-sex chromosome pairs. Since you're wondering about your grandmother's ancestry, Y-DNA is out, since your father's Y chromosome comes from his father, not from your grandmother. Mitochondrial DNA is passed through the female line, so you and your son get it from your mother, which doesn't help you either. That leaves autosomal DNA.

if you go to 23andme, for instance, they can tell you various things about your ancestry based on your autosomal DNA. However, I gather this is unlikely to definitively distinguish a Sephardi ancestry from any other southern European origin. (There have been a lot more studies on Ashkenazi Jewish DNA traits than on Sephardi traits for a bunch of reasons, including what seems to be a way, way smaller and more recent founding population, leading to much more genetic homogeneity.) This is bad news for you. Wikipedia tells me that some studies have revealed differences in Sephardi DNA but it seems unlikely that an off-the-shelf genetic test will identify these for you.

Even if they do, 1492 is many generations ago. In your last 20 generations, you have 2^20 ancestors -- over a million! (Obviously some of these people were the same people as each other, which may be a disquieting thought.) If your family was Jewish, and in Italy, it's likely that at least one of these ancestors was expelled from Spain. It's also likely that at least one was a non-Jewish Italian, one was an Ashkenazi Italian Jew, and so forth, just by sheer force of numbers.

Perhaps a more fruitful route would be examining any family traditions or stories to see if these give you a clue about your family's community in Italy? Even if you can't genetically determine your origin, you may be able to place your family within a community of Sephardi Jews in Italy as opposed to Ashkenazim, which would be pretty good evidence that some or many of your ancestors were in Spain at some point.

Good luck!
posted by goingonit at 6:56 PM on October 26, 2014 [6 favorites]

Thinking about this some more, your father's mtDNA comes from his mother, and 23andme tests mitochondrial DNA. This has a better chance of giving you a useful answer, but sadly, Sephardi mtDNA is hard to distinguish from that of neighboring communities. This paper looks for Sephardi mtDNA signatures, though these are very tentative and probably no off-the-shelf service would look for them. So you have a very slight chance, but you'll have to ask your dad. Again, even if you do this, this will only tell you about your grandmother's direct female line.
posted by goingonit at 7:08 PM on October 26, 2014 [1 favorite]

You know how you can tell a Sephardi? They won't turn down good prosciutto. My father in law (whose family ended up in Croatia after being kicked out of Spain), told me that definition.

You might also see if you can trace a family name perhaps? There might be a Synagogue that would have some records or familial history.
posted by nickggully at 8:24 PM on October 26, 2014 [2 favorites]

Have you looked around on JewishGen.org? There's all sorts of stuff there, including ways to connect to other people researching their family trees.
posted by needs more cowbell at 8:39 PM on October 26, 2014

Response by poster: Thanks all. Unfortunately, there's no one to ask.

It is a cool story, and I'll pass it on to the next generation.
posted by 1066 at 3:22 AM on October 27, 2014

I couldn't really tell from your question -- is your family culturally Jewish now, or is the legend that that all ended when your ancestors emigrated to Italy?

If you don't identify as Jewish now and you don't have Jewish ancestors that are known to you, I suppose it might be interesting to see if you have Ashkenazi ancestry, which is way more likely if you have ancestors who identified as Jewish than if you don't, and also relatively easy to tell from DNA.

Otherwise, I agree with goingonit.
posted by telegraph at 5:15 AM on October 27, 2014

« Older What's this weird fruiting vine?   |   Do professional "military ethicists" exist? Newer »
This thread is closed to new comments.