The amount of a phenylalanine--tRNA ligase, mitochondrial (human) when measured in cerebrospinal fluid. The trait is Ontology of Biological Attributes entry OBA_2056496 (level of phenylalanine--tRNA ligase, mitochondrial (human) in cerebrospinal fluid). Also known as: cerebrospinal fluid phenylalanine--tRNA ligase, mitochondrial (human) amount.