My mother was an Ashkenazi Jew and a Czech Communist Party member who was in the Czech Resistance in 1943, when she met and had an anonymous affair with a fellow Resistance member in Brno, Czechoslovakia.
She became pregnant, and she was arrested soon afterward by the Nazis and transported to the Theresienstadt. I was born in Theresienstadt in 1944. 150 children were born there, 50 were transported to Auschwitz, 50 died, and just 50 survived. I am one of these.
My mother's family were Hungarian and Slovak speaking Jews from Slovakia (Nove Zamky), which was until 1918 ruled by Austro-Hungarian Empire.
I have no real information about who my biological father was. We do know that I am in Y haplogroup G2c and have a very large number of extremely close matches, so it's clear that my father was Jewish and Ashkenazi. Any close matches that would not be related to my mother's side must be from my father's family.
Testing here will help solve the mystery of who my father was. My hope is that if we can narrow down a possible range of individuals and origins, it will be possible to then search in the pre-WWII and WWII records for Jewish men in Brno Czechoslovakia who were still at large in 1943. This will narrow things down in a huge way.