HPP results from mutations in the genes encoding alpha-spectrin, beta-spectrin, and protein 4.1R that affect RBC membrane stability and deformability, leading to shortened RBC survival.
Blood smear will show numerous fragmented RBCs, severe microcytosis, and pyropoikilocytes that resemble the blood smears of thermal burn victims.
Patients present in the neonatal period with jaundice and ongoing hemolytic anemia resulting in transfusion dependence, splenomegaly, and/or gallstones. Aplastic crisis can occur due to parvovirus B19 infection.
HPP and other types of HE are most common in people of African, Mediterranean, or Southeast Asian descent.
R71.8 – Other abnormality of red blood cells
9434008 – Hereditary pyropoikilocytosis
Differential Diagnosis & Pitfalls
- Hereditary elliptocytosis with neonatal poikilocytosis
- Iron deficiency anemia
- Thalassemias (see alpha thalassemia, beta thalassemia)
- Other inherited RBC disorders (eg, hereditary spherocytosis)
- Bone marrow disorders (eg, myelodysplastic syndrome, aplastic anemia)
- Hemolytic anemia due to warm or cold agglutinins
- Other hemolytic anemias (eg, glucose-6-phosphate dehydrogenase deficiency)