Anaemia - Beta Thalassemia (Microcytic)

Question 1

Epidemiology

Answer 1

Sub Saharan Africa
Middle East
Northern Africa
South East Asia

Question 2

Pathophysiology

Answer 2

Defects in beta-globin chains - the gene coding for this protein is on chromosome 11
Single point mutation = autosomal recessive condition
Beta thalaesaemia minor = asymptomatic
Beta thalaesaemia intermedia = inheriting 2 partially defective genes = symptomatic, moderate anaemia, DO NOT require regular transfusions.
Beta thalassaemia major = complete absence of beta globin = not diagnosed immediately due to HbF, life long transfusion needed.

Question 3

Signs

Answer 3

Skeletal deformities
Growth retardation
Osteopenia
Hepatosplenomegaly
BT Major: presents in first year
- Chipmunk face
- Hair on end appearance on skull x-ray (due to increased marrow activity)
- extra medullary haematopoiesis = characteristic head shape = head bossing

Question 4

Symptoms

Answer 4

Symptoms of anaemia
- fatigue
- weakness
- SOB
- Palpitations

Question 5

Diagnosis

Answer 5

FIRST LINE = Blood film, FBC,
GOLD STANDARD = Hb electrophoresis (diagnostic = shows Hb proportions)
SKULL X-RAY - hair on end appearance

Question 6

Treatment

Answer 6

Regular transfusion
Iron chelation (prevent Fe transfusion overload) - desferrioxamine
- side effects = deafness, cataracts
Splenectomy
- wait till after 6 year old as spleen plays defective role vs encapsulated bacteria
Folate supposed - haemolytic anaemia
GOLD STANDARD = BM stem cell transplant