Define Beta-Thalassaemia Major. Describe its pathophysiology, clinical features, investigations and management.

Definition

• Beta-thalassaemia major is an autosomal recessive disorder caused by defective (absent or reduced) synthesis of the beta-globin chains of haemoglobin.
• The resulting excess alpha chains precipitate in red-cell precursors, causing ineffective erythropoiesis and haemolysis, and a severe transfusion-dependent anaemia.

Pathophysiology

Absent/reduced β-chain synthesis → Excess α-chains precipitate in RBC precursors → Ineffective erythropoiesis + haemolysis → severe anaemia → Marrow hyperplasia (bone expansion) + extramedullary haematopoiesis → Increased iron absorption + transfusions → iron overload

Clinical Features

• Presents from 6 months of age onwards (as protective fetal haemoglobin declines).
• Severe progressive pallor, failure to thrive, lethargy and poor feeding.
• Hepatosplenomegaly (extramedullary haematopoiesis and haemolysis).
• Thalassaemic facies — frontal bossing, maxillary prominence ('chipmunk' face) and skull bossing from marrow expansion.
• Growth retardation and delayed puberty.

Investigations

• Haemogram — severe microcytic hypochromic anaemia.
• Peripheral smear — anisopoikilocytosis, target cells, nucleated RBCs and basophilic stippling.
• Haemoglobin HPLC/electrophoresis — markedly raised HbF, raised HbA2, and reduced/absent HbA (diagnostic).
• X-ray skull — 'hair-on-end' appearance; raised serum ferritin (iron overload); DNA analysis for mutations.

Management

• Regular blood transfusions — 'hypertransfusion' to maintain pre-transfusion Hb ~9–10.5 g/dL (suppresses marrow expansion and allows normal growth).
• Iron chelation therapy — deferasirox/deferiprone (oral) or desferrioxamine (subcutaneous) to prevent and treat transfusional iron overload.
• Folic acid supplementation; splenectomy for hypersplenism/rising transfusion needs (with pre-splenectomy vaccination and penicillin prophylaxis).
• Haematopoietic stem-cell (bone-marrow) transplantation — the only curative option.

Complications

• Iron overload (the major cause of morbidity/mortality) — cardiac (cardiomyopathy, arrhythmia), endocrine (diabetes, hypothyroidism, hypogonadism, growth failure), and liver disease.
• Transfusion-transmitted infections (hepatitis B, C, HIV); alloimmunisation.
• Hypersplenism; gallstones; chronic anaemia effects.

Prevention

• Carrier (trait) screening and genetic counselling — especially before marriage/pregnancy.
• Prenatal diagnosis (chorionic villus sampling) in at-risk couples.
• Community awareness and premarital/antenatal screening programmes.

The Thalassaemia Spectrum

Transfusion & Monitoring

• Regular packed-cell transfusions every 2–4 weeks to maintain growth and suppress marrow.
• Monitor serum ferritin and organ iron (cardiac/liver MRI) to guide chelation.
• Screen for endocrine complications, viral infections and alloantibodies.

Psychosocial & Supportive Care

Thalassaemia major is a lifelong, demanding illness; families need counselling, adherence support (chelation is burdensome) and social support, alongside management of complications.

Prognosis

• With good transfusion and chelation, survival into adulthood with reasonable quality of life is achievable; poor chelation adherence leads to fatal iron-overload cardiomyopathy.
• Stem-cell transplantation offers cure in suitable children with a matched donor.

Role of Splenectomy

• Considered for hypersplenism with rising transfusion requirements or symptomatic splenomegaly.
• Requires pre-operative vaccination (pneumococcus, Hib, meningococcus) and lifelong penicillin prophylaxis (post-splenectomy sepsis risk).

Complications BY System (iron Overload)

• Cardiac — cardiomyopathy and arrhythmia (leading cause of death).
• Endocrine — diabetes, hypothyroidism, hypoparathyroidism, delayed puberty, short stature.
• Hepatic — fibrosis/cirrhosis; and transfusion-transmitted hepatitis.