Eight of the ten fully Jewish kits I have access to showed related parents in the “Are Your Parents Related” (AYPR) tool on GEDmatch. I am wondering if this level of relatedness (about a 4th cousin) is generally true among Ashkenazim and other endogamous populations. Or perhaps the GEDmatch parameters need some tweaking?
Also a number of married jewish couples I know have discovered that they share a DNA segment. Personally I share 11 cM on the X with my late husband even though I have only one Jewish grandparent. Most testing companies show me as about 30% Jewish.
I can understand that when people live in the same general area for generations, one could easily marry 3rd and 4th cousins. I also know that in the past, cousin marriages were not uncommon among Jews.
I invite all tested fully Jewish people to run that free tool at GEDmatch and then fill out my form on the next page. Please fill it out even when they are not showing as related to help with my statistics.
Should you be worried if you have duplicated DNA from each parent like this? Maybe. If there is a deleterious mutation, there it could have health implications. In that case, you might run your DNA through Promethease to check it.
Here is my form:
You should do this for Catholic French Canadians also.
You and your readers might be interested in the endogamy capabilities at Graphs for Genealogists. The only active project at present is with French Canadian families. Mennonite data are being analyzed. But there is not yet an Ashkenazim project.
Kitty, where are you getting that figure of 97% Ashkenazi? I get all sorts of different results at different sites and Gedmatch offers a choice of programs. Usually I get anywhere from about 89% to 100% Jewish. Jtest reports only 25% Ashkenazi for me. All of my grandparents are presumed Ashkenazi. Gedmatch says my parents aren’t related.
Another interesting thing I’ve noted since the last time FTDNA changed their algorithms is that all my first cousins on one side of my family or the other who used to be correctly identified as to my maternal or paternal side are now all showing up as being on both sides. Since that last change was supposed to eliminate inclusion of small segments for endogamous populations this result seems counter intuitive to me. Any thoughts? Could it be related in any way to the AYPR situation?
The main testing companies usually show most of the fully Jewish people that I know as 97% or more. Not The GEDmatch Jtest.
My father, half English, half Scottish, all grandparents born in Britain, had one Jewish seg. A little surprising. Of course there was a Jewish population there in the early Middle Ages. It is Ashkanazi. I know it is on the English side because a 4th cousin, still in England, shares the same segment. The family in modern times lived in Durham, north of York where the victims of a pogrom were recently discovered in a well.