Well I thought I had found a real cousin on the German Jewish side due to a few common surnames but no luck finding the relationship yet. Sadly there is a large match on our X but the common surnames are not on a branch where X could come from. Of course one of the problems in German Jewish genealogy is that all but a few prominent families had no fixed surnames (they used their father’s name) until 1813/14.
Even worse she mainly matches me on segments that are what I call “Ashkenazi Pile Ups” or locations where there are well over 30 people matching me but not my Dad for more than 5cm. By comparison I notice only one such pile up on my 100% Norwegian father’s matches at chromosome 9, at about 80,000. But that will be the topic for another post.
These are the three pile ups my new distant cousin matches:
Chromosome 2: 45 matches for this segment at 23andme
| 150.1 | 163.3 | 9.9CM |
Chromosome 4: 80 matches for this segment at 23andme
some start at 18.1 and some end at 25.0
| 19.4 | 24.8 | 7.2CM |
Chromosome X: about 30 matches for me, 50 for my brother…. hmmm
a few are longer than this
| 123.4 | 137.8 | 14.1CM |
For those of you who are wondering where to find this data on 23andme you can download all the segments that match yours with the name of the donor (most will be anonymous) by going to “ancestry labs” under ‘My Results” and clicking on “Countries of Ancestry.” Scroll down the page to the long blue button where you can download a CSV of all your matches. [updated 27 dec 2013 – n.b. you can get this data and more by using the http://DNAgedcom.com site to do the downloads]
There are a few more pile ups in my and my brother’s matches than these …
chromosome 1: 31 matches for this segment
| 47.0 | 55.3 | 7.2 |
chromosome 1: and 45 matches for this segment
| 107.9 | 116.6 | 11.1 |
chromosome 2: about 20 or so
| 16.9 | 24.5 | 9.1 |
to be continued in a future post …. as I find more of these
I googled around and did not find anywhere that listed known ashkenazi genetic segments. Would love to hear if anyone knows more about this. I am sure 23andme has this information as they mark many 3 segment cousins as “distant” so presumably all those segments are known ashkenazi DNA segments.
Edited March 10, 1015 – replaced the incorrect term “hot spot” with the correct term “pile up.” Hot spot has a specific meaning in genetic genealogy which is a place that recombination cross overs happen more often.
I have since discovered that the term genetic hotspot refers to places where recombination cross overs are frequent so I will have to rename these as persistent DNA segments, PDSs unless there is a better suggestion.
Interesting. I’ve noticed the same phenomenon in FTDNA’s Family Finder results. I have one Jewish 2Ggrandfather. However, the locations where I have the greatest excesses of Jewish matches are different: chromosome 2 at 120963563 to 140029739, chr 10 at 16448878 to 68307817, chr 11 at 59791005 to 90746870, chr 21 at 22255031 to 32136224, X chr at 91045591 to 138635924, and especially chr 9 at 28130215 to 100329812. I was wondering whether anyone had identified characteristically Ashkenazi Jewish segments. But now I’m thinking that what’s characteristic of Ashkenazi ancestry is having certain short segments with whopping numbers of matches to speculative cousins, regardless of where these segments are.
Yes endogamous populations like Ashkenazim do look like that. One researcher told me to ignore ashkenazi matches with no segment of at least 23cM.
There is a new section under IBD at the ISOGG wiki about pile ups which quotes some of the latest research http://www.isogg.org/wiki/Identical_by_descent#Excess_IBD_sharing
You can also Check out some of my other articles on Ashkenazi DNA http://blog.kittycooper.com/tag/ashkenazi/
And hopefully soon I will do another which includes that pile up research
Hi Kitty – This is fascinating. I downloaded my data and sorted to see the pile ups. These segments in my DNA are different than yours, but are in clusters where many of the testers declared Ashkenazi.
Chr 1, 201 to 209.9. 39 people
Chr 18, 60.9 to 66.1 24 people
Also interesting is that none of the 39 on Chr1 are the same as the 24 on Chr18. All unique matches in these separate pileups.
Thank you for sharing this intriguing info.
Becka
Becka –
Yes I am overdue to write a post about pile ups. I corrected my use of the word hot spots above since now there is a term for this: pile ups.
There is a good section at the ISOGG wiki about pile ups:
http://www.isogg.org/wiki/Identical_by_descent#Excess_IBD_sharing
and there is this blog post… Chromosome pile ups in genetic genealogy: examples from 23andMe and FTDNA. Genealogy and Genomics blog, 31 January 2015 at http://ourpuzzlingpast.com/geneblog/2015/01/31/chromosome-pile-ups-in-genetic-genealogy-examples-from-23andme-and-ftdna/
a fascinating subject
Kitty
“I googled around and did not find anywhere that listed known ashkenazi genetic segments. Would love to hear if anyone knows more about this.”
Has anyone heard of any such lists since this post in 2015?
Dnapainter includes some pile-up zones in their map but these are not specifically ashkenzi as far as I know.
Interesting I’ve found this blog interesting I’ve a distant Ashkenazi as well as Sephardic ancestry and I’ve one segment with over 50 Ashkenazi all match me and each other. Endogamy makes sense.
Like Phillipe, I have the same ancestry, despite being predominantly German. A lot of matches are on a segment of Chromosome 13 for me. Often these matches are in France or the Netherlands or their ancestors made it to the USA or UK. They often have Middle Eastern ancestry too. I have a few connected to Spain, directly or indirectly (Cuba, Mexico, etc.).
Meanwhile on Chromosome 9, a segment to the right… most of my matches there are exclusively Ashkenazi, with or without other unrelated ancestries.
And then I have other stray “Jewish” matches, with other chromosomes involved… so not a “pile up”.
I’d love to know my ancestor’s identity… who somehow mixed their DNA with a German or Frisian person, probably in the late 1700’s. However, my more realistic goal is just to identify the ONE branch on my tree. My parents are dead and no one else will test and share! I found this post today through a Google search. I’ll look to more recent information about pile ups.
I’d also like to know who the heck was Swedish, among my ancestors. I have Swedes who are apparently my 3rd to 5th cousin matching me at a couple of sites, with nary a German (Pomeranian or otherwise) on their sometimes very extensive family trees.
Your Swedish ancestry may well be from the 30 years war when Swedish soldiers overran much of Germany:
https://en.wikipedia.org/wiki/Thirty_Years%27_War
As to your occasional jewish match, they may have a non jewish ancestor or you may have a jewish ancestor way back.
Try and convince some 2nd cousins to test, they are very useful for figuring out which line has given you which DNA. While many German Americans have tested, almost no Germans in Germany have done DNA testing. A few at family tree DNA and MyHeritage…
Also you might try using automated clustering to see patterns in your matches and associate them with specific lines.
https://blog.kittycooper.com/2018/12/automatic-clustering-from-genetic-affairs/
I have lots of posts on this blog that can help. I presume you have uploaded to GEDmatch? Try the Eurogens admix calculator called Jtest to see if you have any traces of jewish and also use K12 and K13 but in general, ethnicity from DNA is not very reliable yet.
I have remote Jewish ancestry and by using Gedmatch I found some pile-up regions of about 9-10 cM containing almost exclusively Ashkenazi matches. On Chr 22, 1, 2, 19… It can happen in endogamous populations, I believe.
Yes it can. That was a good way to research it.