The known ancestors of my maternal grandmother, Elisabetha Antoni, have all different family names. For this reason, I was not thinking much about endogamy in my family until recently, when the results of two of my grandmother’s second cousins came in.
The idea behind testing V.A. and E.A.S. was the hope to map additional DNA segments to the line of my great grandfather Heinrich Antoni. To my surprise, however, the amount of shared DNA was unusually high for a relationship this distant.
According to the Bettinger table https://dnapainter.com/tools/sharedcm, the average amount of shared DNA for a 2C1R is 123cM and 74cM for a 2C2R.
However, the results of my family looked like this:
What was going on here?