Kaethe Danziger (geb. Halberstaedter) mentions a Bruno Apt, born 1880, from Langendorf who married Elsa Bendtheim and had sons Guenther and Hans. The 1939 census of Berlin lists Bruno, Else and Hans at Neue Jakobstrasse 18. Guenther is not listed with them.

Kaethe Danziger (geb. Halberstaedter) notes that the family emigrated to Argentina; however records show that Bruno and Elsa were deported to Riga on 25.01.1942. RG, a granddaughter of Emil Gadiel says that Hans was also killed by the Nazis, and a Yad Vashem record attests to his deportation to the Warsaw ghetto. mappingthelives.org lists a Guenter Hermann Apt born 22.05.1920 in Berlin who emigrated to Argentina in 1937.