Red Cells 2

Question 1

4 types of Thalassaemia

Answer 1

• Homozygous alpha zero thalassaemia
• Thalassaemia major
• Thalassaemia intermedia
• Thalassaemia minor

Question 2

Describe homozygous alpha zero thalassaemia

Answer 2

• No alpha chains

- Incompatible with life (hydrops fetalis)

Question 3

Describe Thalassaemia major

Answer 3

• No beta chains
• Transfusion dependent anaemia
• Presents in 1st yr with severe anaemia + failure to thrive
• Extramedullary haematopoiesis (response to anaemia)
• Osteopenia +expansion of ineffective bone marrow

Question 4

Describe Thalassaemia intermedia

Answer 4

• Doesn’t require transfusions

- May be splenomegaly

Question 5

What is Thalassaemia

Answer 5

• Genetic disorder
• Unbalanced Hb synthesis, with under-production (or no production) of 1 globin chain
• Damages RBCs membranes causing haemolysis

Question 6

Describe thalassaemia minor

Answer 6

• Trait or carrier state
• Usually asymptomatic
• Mild, well tolerated anaemia
• May worsen with pregnancy

Question 7

What happens to the skull in thalassaemia major

Answer 7

Skull bossing (due to extramedullary haematopoiesis)

Question 8

What is extramedullary haematopoiesis

Answer 8

RBC production outside the bone marrow

Question 9

What is seen on a skull x-ray in thalassaemia major

Answer 9

“Hair on end” sign (due to bone marrow expansion

Question 10

Rx of thalassaemia major

Answer 10

• Transfusions, 4-6 weekly
• Careful of iron overloading
• Iron chelation therapy
• Bone marrow transplantaion = curative

Question 11

What is used in iron chelation therapy

Answer 11

Oral Deferiprone + Subcutaneous Desferrioxamine

Ascorbic acid increases urinary excretion of iron

Question 12

What causes sideroblastic anaemia

Answer 12

Defects in mitochondrial steps of haem synthesis (ALA synthase mutations)

Question 13

3 causes of inherited anaemias

Answer 13

Defects in:

• RBC membrane
• RBC metabolism (enzymes)
• Haemoglobin production