Pyruvate kinase deficiency: epidemiology, molecular analyses and modern diagnostic approaches (literature review)

Red cell pyruvate kinase deficiency is the most common glycolytic defect causing congenital nonspherocytic hemolytic anemia. Pyruvate kinase is the enzyme involved in the last step of glycolysis – the transfer of a phosphate group from phosphoenolpyruvate producing the enolate of pyruvate and ATP (50 % of total energy ATP of erythrocytes). ATP deficiency directly shortened red cell lifespan. Affected red blood cells are destroyed in the splenic capillaries, leading to the development of chronic hemolytic anemia. It is an autosomal recessive disease, caused by homozygous and compound heterozygous mutations in the PKLR gene. There are no exact data on the incidence of pyruvate kinase deficiency, but the estimated frequency varies from 3: 1,000,000 to 1:20,000. The clinical features of the disease and the severity are highly variable. Diagnosis of pyruvate kinase deficiency is based on the determination of pyruvate kinase activity and molecular genetic study of the PKLR gene. The variety of clinical manifestations, possible complications, as well as the inaccessibility of diagnostic methods complicate the diagnosis.