PYRUVATE-KINASE DEFICIENCY

Pyruvate kinase (PK) deficiency was initially described by Valentineet al. in 1961. Since then, more than 300 cases have been described, including 65 in Japan. PK deficiency is the most common hereditary nonspherocytic hemolytic anemia among several red cell enzyme defects of the Embden-Meyerhof glycolytic pathway. The clinical manifestations are highly variable. Splenectomy usually increases the hemoglobin level by about 2 g/100 mL. Standardization of methods for characterization of PK variants was achieved in 1979. There are four PK isozymes, Mi, M2, L and R, in mammalian tissues. We have clarified the switch from M2-type to L-type PK during maturation of erythroid precursor cells. Recently we cloned and sequenced a full length human L-type PK cDNA. It will be useful to clarify the molecular basis of PK deficiency. © 1990 The Canadian Society of Clinical Chemists.