Haematology - Hereditary Spherocytosis

Question 1

What causes hereditary spherocytosis?

Answer 1

Autosomal dominant mutation in genes that code for RBC proteins
- Spectrin (alpha and beta)
- Ankyrin
- Band 3 protein
- Protein 4.2

Causing sphere shaped RBCs, making them fragile and easily destroyed when passing through spleen

Question 2

How does hereditary spherocytosis present?

Answer 2

Jaundice
Anaemia
Gallstones
Splenomegaly

Question 3

What is a haemolytic crisis?

Answer 3

Haemolysis, anaemia and jaundice are more significant

Triggered by infections

Question 4

What is an aplastic crisis?

Answer 4

In an aplastic crisis there is increased anaemia, haemolysis and jaundice without bone marrow producing new RBCs

Bone marrow usually responds to haemolysis by producing RBCs more quickly, causing reticulocytes in the blood

Can occur in hereditary spherocytosis

Question 5

What triggers an aplastic crisis in hereditary spherocytosis?

Answer 5

Parvovirus B19

Question 6

How is hereditary spherocytosis diagnosed?

Answer 6

Family history
Clinical features
Blood film - spherocytes
Raised MCV
Raised reticulocytes

Question 7

How is hereditary spherocytosis treated?

Answer 7

Folate supplementation
Splenectomy

Cholecystectomy if symptomatic gallstones
Transfusions may be needed in an acute crisis

Question 8

What is hereditary elliptocytosis?

Answer 8

Very similar presentation except RBCs are ellipse shaped

Also autosomal dominant