This document discusses hereditary spherocytosis (HS), an inherited disorder caused by defects in the red blood cell membrane skeleton. HS is characterized by spherical red blood cells that are less deformable and vulnerable to splenic sequestration and destruction. The defects are primarily in proteins like ankyrin, band 3, spectrin or band 4.2 that make up the membrane skeleton. This leads to a reduced red blood cell life span of 10-20 days instead of the normal 120 days. Clinical features include anemia, splenomegaly, jaundice, and hemolytic crises from infections. Diagnosis involves tests like peripheral smear, bone marrow examination, and osmotic fragility testing. Treatment

1. HEREDITARY
SPHEROCYTOSIS
Dr.T.Arivazhagan
Department of
Pathology

2. Definition
• HS is an inherited disorder caused by
intrinsic defects in the red cell membrane
skeleton that render red cells spheroid, less
deformable, and vulnerable to splenic
sequestration and destruction.

3. Introduction
1.Autosomal dominate
2.Highest prevalence in northern
Europe.

4. Pathogenesis
1. Deformability & durability of the red cell
membrane depends on the physico chemical
properties of the specialized membrane skeleton
2. Chief protein called spectrin
3. Consists of 2 polypeptide chains (α &β)
4. Head & Tail regions

7. • Mutations that lead to an insufficiency of the
membrane skeletal components.
• Affect the red cell life span 10 to 20 days from 120
days.
• Mutations mainly occurs in the ANKYRIN, BAND 3,
SPECTRIN or BAND 4.2.

8. Primary
membrane
skeletal
defects
Decreased
membrane
stability
Membrane
loss
Decreased
surface to
volume ratio
SpherocytosisReduced
deformability
Splenic
trapping
Erythrocytosis
Reduced
glucose &
PH
Phagocytosis
Extra
vascular
hemolysis

9. Morphology
1. Spherocytosis
2. Small , dark staining red cells lacking the central
zone of pallor
3. Reticulocytosis
4. Marrow erythroid hyperplasia
5. Hemosiderosis
6. Pigmented stones
7. Moderate splenomegaly

10. Clinical features
1. Anemia
2. Splenomegaly
3. Jaundice
4. Aplastic crisis – Parvo virus
5. Hemolytic crisis – Infective mononucleosis

11. Investigations
1. Peripheral smear – Spherocytes
2. Bone marrow – Erythroid hyperplasia
3. Osmotic fragility Test- Hemolysis starts at higher
concentration itself
4. Auto hemolysis test
5. Acidified glycerol hemolysis test
6. Eosin 5 maleimide test

16. Treatment
1.Blood transfusion
2.Splenectomy