The amount of a Rap1 GTPase-GDP dissociation stimulator 1 (human) when measured in cerebrospinal fluid. The trait is level of Rap1 GTPase-GDP dissociation stimulator 1 (human) in cerebrospinal fluid (OBA_2058075). Also known as: cerebrospinal fluid Rap1 GTPase-GDP dissociation stimulator 1 (human) amount.