Hereditary pyropoikilocytosis. Clinical and laboratory analysis in eight infants and young children

L. DePalma and N. L. Luban
Department of Laboratory Medicine, Children's National Medical Center, Washington, DC.

OBJECTIVE--To describe the mode of presentation and natural history of hereditary pyropoikilocytosis to promote earlier diagnosis and improve treatment of this disorder. DESIGN--Retrospective case analysis. SETTING--Tertiary care pediatric medical center. PARTICIPANTS--Eight children referred for examination. INTERVENTIONS--Treatment of symptomatic anemia and complications. MEASUREMENTS/MAIN RESULTS--Hereditary pyropoikilocytosis was responsible for a very characteristic perinatal course in our patient cohort. All patients had hyperbilirubinemia requiring either exchange transfusions or phototherapy. Peripheral blood smears at birth revealed nucleated red blood cells, marked poikilocytosis, microcytosis, and reticulocytosis. All other pertinent laboratory studies (eg, immune hemolysis, sepsis, hereditary spherocytosis, etc) were noncontributory. Specific red blood cell membrane analysis clearly identified these patients as having hereditary pyropoikilocytosis. Follow-up evaluation of these patients (in one instance spanning 12 years) determined that this disorder is associated with a clinically apparent anemia but an excellent prognosis. CONCLUSIONS--Red blood cell membrane analysis should be performed in neonates with a hemolytic anemia requiring therapy in which no identifiable cause can be ascertained with a conventional diagnostic examination.