Thalassaemia

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management

Definition

Thalassaemia is an inherited haemoglobinopathy characterised by defective synthesis of globin chains, leading to microcytic anaemia and haemolysis.

Aetiology

  • Alpha thalassaemia: deletion or mutation of alpha-globin genes.
  • Beta thalassaemia: mutations in beta-globin genes causing reduced or absent beta-chain production.
  • Carrier state: asymptomatic individuals with one affected gene.
  • Thalassaemia intermedia: moderate anaemia with occasional transfusion need.
  • Thalassaemia major: severe anaemia requiring lifelong transfusions.

Pathophysiology

  • Imbalanced globin chain production leads to ineffective erythropoiesis.
  • Excess unpaired globin chains precipitate, causing red cell destruction.
  • Chronic haemolysis and extramedullary haematopoiesis result in skeletal deformities and hepatosplenomegaly.

Risk Factors

  • Family history of thalassaemia.
  • Ethnic background (higher prevalence in Mediterranean, African, Middle Eastern, and South Asian populations).
  • Consanguinity.

Signs and Symptoms

  • Thalassaemia minor: asymptomatic or mild anaemia.
  • Thalassaemia major: pallor, growth retardation, jaundice.
  • Hepatosplenomegaly due to extramedullary haematopoiesis.
  • Iron overload from frequent transfusions leading to endocrinopathies and cardiomyopathy.
  • Characteristic facial changes in severe cases (frontal bossing, maxillary overgrowth).

Investigations

  • Full blood count (FBC): microcytic hypochromic anaemia.
  • Haemoglobin electrophoresis: confirms abnormal haemoglobin pattern.
  • Iron studies: differentiates from iron deficiency anaemia.
  • Genetic testing: identifies specific mutations.
  • Liver function tests (LFTs) and ferritin: assess iron overload.

Management

1. Supportive Care:

  • Folic acid supplementation.
  • Regular transfusions in thalassaemia major to maintain haemoglobin >9 g/dL.

2. Iron Overload Management:

  • Iron chelation therapy (deferasirox, deferoxamine) to prevent organ damage.

3. Curative Treatment:

  • Allogeneic stem cell transplantation in selected cases.

4. Referral:

  • Haematology: all confirmed cases for long-term management.
  • Genetics: counselling for affected families.
  • Endocrinology/cardiology: for iron overload complications.
HaematologymypanotesThalassaemia