A compound attribute that is the ratio of amount of porphobilinogen deaminase (human) in blood to amount of pyruvate kinase PKLR (human) in blood. The trait is Ontology of Biological Attributes id OBA_2053032 (HMBS/PKLR protein level ratio in blood). Also known as: the ratio of amount of porphobilinogen deaminase (human) in blood to amount of pyruvate kinase PKLR (human) in blood.