Isaäc Gerritse was the son of Jacob Gerritse and Marianna Lootsteen. He married Marianne de Klijn in Amsterdam in 1907. She was the daughter of Nathan de Klijn and Mietje Visser. The couple had six children: Marie, Sophia, Nathan, Jacob, Rebecca and one child that survived the war.
Addition of a visitor of the website
According to a list with shops of Jewish owners, compiled by the Amsterdam police in 1940, this family had a fish and fruit store, address: Westerstraat 120 in Amsterdam.
Abstracts of the police archives which are currently at the Amsterdam municipal archives