Pyruvate kinase is the most commonly inherited metabolic disorder of glycolysis Pyruvate kinase Produces an ATP at the level of substrate level phosphorylation(SLP) Deficiency loss of ATP inability to maintain ion pumps in erythrocytes-Hemolysis Autosomal recessive Presentation Hydrops fetalis, Prolonged neonatal jaundice, Anemia In a glycolytic enzyme deficiency, there is a reduced rate of glycolysis, leading to decreased ATP production. This results in a few alterations in the RBC membrane, thereby leading to changes in cell shape. Such deformed RBCs are later phagocytosed by cells of the reticuloendothelial system, and this results in a state of hemolytic anemia. The most common enzyme deficiency causing hemolytic anemia is glucose-6-phosphate dehydrogenase deficiency(pentose phosphate pathway). The second most common enzyme deficiency causing hemolytic anemia is the pyruvate kinase. Note: Though hemolysis is seen in PFK-1 deficiency, it does not always manifest as anemia.