Synopsis
Differentiate alpha- from beta-globin underproduction, distinguish carrier states from iron deficiency, recognise clinically significant genotypes, and coordinate molecular diagnosis, reproductive counselling and complication surveillance.
- Thalassaemias are inherited reductions in alpha- or beta-globin synthesis, causing microcytosis, globin-chain imbalance and ineffective erythropoiesis of variable severity.
- Trait commonly produces a low MCV and MCH out of proportion to mild or absent anaemia, with a relatively preserved red-cell count.
- Check ferritin before attributing microcytosis to carrier status; iron deficiency and thalassaemia can coexist and only documented deficiency should receive iron.
Key red flags
Both partners carrying alpha-zero deletions in cis creates a pregnancy at risk of alpha-thalassaemia major requiring urgent fetal referral.
Investigation priorities
Define microcytosis, red-cell number and haemolytic morphology.
Management branches
A low MCV or MCH persists with mild or no anaemia.
- Obtain ferritin with inflammatory context and review diet, bleeding, pregnancy, transfusion, ancestry and family blood-count history.
- Perform accredited haemoglobin analysis before iron treatment when deficiency is not established, recognising the limitations for alpha trait.
Key medicines
Folic acid in significant haemolysisSpecialists commonly prescribe 5 mg orally once daily during pregnancy or sustained HbH or intermedia haemolysis when erythropoietic demand makes folate depletion plausible.
Iron replacement for proven deficiencyUse the NICE or BNF oral elemental-iron regimen and duration only after deficiency is demonstrated, adjusting frequency for tolerance and expected absorption.