The amount of a inositol polyphosphate-4-phosphatase type I A (human) when measured in cerebrospinal fluid. The trait is level of inositol polyphosphate-4-phosphatase type I A (human) in cerebrospinal fluid (OBA_2080523). Also known as: cerebrospinal fluid inositol polyphosphate-4-phosphatase type I A (human) amount.