Hemolytic anemia due to red cell pyruvate kinase (PK) deficiency is a metabolic disorder characterized by a variable degree of chronic nonspherocytic hemolytic anemia.

Neonatal jaundice refers to a yellowing of the skin and other tissues of a newborn infant as a result of increased concentrations of bilirubin in the blood. Neonatal jaundice affects over half of all newborns to some extent in the first week of life. Prolonged neonatal jaundice is said to be present if the jaundice persists for longer than 14 days in term infants and 21 days in preterm infants.