User Comments:
I believe that Abraham is the brother of Aleksander (already researched). They have the same ghetto addresses. (Danziger 6, Sudeten 20 2, ABG Dec. 13, 1942 Konigsber).
For the same reasons, I believe that Rywka is their mother (found by whoever researched Aleksander), and Wigdor is their father. Both the possible parents have ages that make them plausible and they are the only people with the last name Przytycki to live at these same addresses.