Haematologt

Question 1

What is the inheritance of hereditary spherocytosis?

Answer 1

AD (usually chromosome 8) leads to a defect in the gene coding for the RBC membrane proteins.

Question 2

How does hereditary spherocytosis present?

Answer 2

Anaemia, jaundice, splenomegaly

Though screening programs of first degree relatives

Question 3

What are the complications of hereditary spherocytosis ? (3)

Answer 3

Anaemia
Aplastic crisis (secondary to infection).
Pigment Gallstones

Question 4

What investigations would you do in suspected hereditary spherocytosis?

Answer 4

FBC, MCV, blood film (spherocytes and haemolysis)
Haemolytic screen - LDH (high) unconj bill (high), haptoglobin (decreased of absent) reticulocyte count (high) DCT (to rule out immune haemolysis)
EMA binding or Osmotic fragility test (if EMA not available)

Question 5

Treatments for hereditary spherocytosis?

Answer 5

Folic acid supplementation

Splenectomy if mod to severe (then require prophylactic antibiotics and keep up to date with vaccinations)

Question 6

Why are splenectomies performed in hereditary spherocytosis?

Answer 6

Abnormal RBCs are spherocyte shaped instead of biconcave. The abnormal RBCs are broken down in the spleen (shorter life span). A splenectomy essentially removes haemolysis in these patients.