The amount of a heparan sulfate glucosamine 3-O-sulfotransferase 3A1 (human) when measured in cerebrospinal fluid. The trait is level of heparan sulfate glucosamine 3-O-sulfotransferase 3A1 (human) in cerebrospinal fluid (OBA_2081877). Also known as: cerebrospinal fluid heparan sulfate glucosamine 3-O-sulfotransferase 3A1 (human) amount.