Synopsis
Recognise thalassaemia carrier states and clinically significant disease, interpret microcytosis and haemoglobin studies without reflex iron treatment, identify transfusion-related complications, and provide accurate family and reproductive counselling through specialist services.
- Thalassaemias reduce alpha- or beta-globin production; severity ranges from an asymptomatic carrier state to lifelong transfusion-dependent anaemia.
- Think of trait when microcytosis and low MCH are disproportionate to the anaemia, the red-cell count is relatively preserved and ferritin is not low.
- First-line tests are FBC with indices, reticulocytes, ferritin with inflammatory context, blood film and specialist haemoglobin analysis.
- Raised HbA2 commonly supports beta thalassaemia carrier status, but infancy, recent transfusion and coexisting iron deficiency complicate interpretation.
- Alpha thalassaemia carrier status can have normal routine haemoglobin fractions; definitive diagnosis may require DNA analysis when it changes reproductive or clinical decisions.
- Do not prescribe iron for thalassaemic microcytosis unless iron deficiency is independently demonstrated.
- Reference-standard subtype confirmation combines specialist haemoglobin analysis with molecular testing where required; no single screening result defines every alpha and beta genotype.
- Transfusion-dependent disease needs protocolised phenotype-matched red-cell transfusions, chelation and surveillance of liver, heart, endocrine function, growth, puberty and bone health.
- Carrier status is usually clinically benign but reproductively important; offer clear inheritance counselling and partner testing at the appropriate life stage.
- Document the exact genotype or laboratory conclusion rather than writing only 'thalassaemia', because management implications differ greatly.
Key red flags
Profound pallor, tachycardia, poor feeding, growth failure, abdominal distension or hepatosplenomegaly in later infancy may indicate transfusion-dependent beta thalassaemia.
Fever, rigors, urticaria, wheeze, hypotension, loin pain or haemoglobinuria during transfusion signals an acute reaction and the transfusion must be stopped immediately.
New dyspnoea, oedema, exercise intolerance, palpitations or syncope in a regularly transfused child raises concern for cardiac iron overload or anaemia.
Delayed puberty, faltering height, diabetes symptoms or bone pain can reflect endocrine and skeletal consequences of iron overload.
A child with splenectomy or functional hyposplenism and fever needs urgent sepsis assessment despite antibiotics and immunisation.
Microcytosis with additional cytopenias, blasts, systemic illness, jaundice or an unexpectedly low haemoglobin needs a wider diagnosis rather than automatic attribution to trait.
Investigation priorities
Define anaemia severity, microcytosis and marrow response using age-appropriate reference ranges.
Management branches
A well child has low MCV or MCH without severe anaemia.
- Check ferritin with inflammation and review diet, bleeding and family history.
- Arrange specialist haemoglobin analysis when stores are adequate or microcytosis is disproportionate.
- Avoid continued iron when deficiency is absent and record the confirmed carrier result clearly.
- Provide written information and future reproductive-counselling advice.