Gerrit Lootsteen was a son of Sander Lootsteen and Schoontje Wennik. He married in Amsterdam on 25 November 1931 to Mietje Lelie, a daughter of Haim Lelie and Kaatje Beugeltas..
City Archive of Amsterdam, archive card of Sander Lootsteen and Kaatje Beugeltas.
In addition, a Jokos file (number 51951) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.