Hereditary spherocytosis is the most common inherited red blood cell membrane disorder in individuals of northern European ancestry with an incidence of 1 case per 2000-5000 individuals. Deficiency or dysfunction of erythrocyte membrane proteins (ankyrin, band 3, α and β spectrins, protein 4.2) result in weakened interactions between the lipid bilayer and membrane skeleton leading to formation of spherocytes with decreased deformability and increased osmotic fragility. Premature splenic destruction of abnormal spherocytes is a primary cause of hemolysis in hereditary spherocytosis.
Sickle-cell anemia, also called sickle-cell disease, is a hereditary disorder in which abnormal hemoglobin (HbS) within the red blood cells causes the cells to take on abnormal sickle shapes.
