Hereditary spherocytosis

A congenital RBC structural membrane disorder that is usually Autosomal Dominant and leads to increased numbers of RBCs with spherical shape (round with no central pallor). The defect is usually associated with a cytoskeletal scaffold of the RBC membrane. Mutations in the Spectrin genes (Spectrin protein is a strcutural protein), Ankyrin gene, Band 3 or Band 4.2 are the most common findings. Severe cases can lead to a hemolytic anemia. Usually there is an increase in MCHC. Additionally, the cells are more fragile and will give a positive osmotic fragility test result.