Thalassaemia (Alpha & Beta)

Meet the patient

A nine-month-old boy of Greek ancestry is brought in pale, listless and off his feeds, having slipped off his weight centile over six weeks. His forehead looks prominent, his cheeks full, and his belly is distended by a spleen crossing the midline. The full blood count shows haemoglobin 55 g/L, MCV 60 fL — and the Hb electrophoresis is dominated by fetal haemoglobin, exactly the picture you expect as HbF falls and then re-rises in beta-thalassaemia major.^[1][2]

Hold two questions for the rest of the topic: how many globin genes did this child lose, and on which chromosome? That single arithmetic predicts the phenotype, the transfusion need and the risk to the next sibling. The other patient you will meet just as often is the well adult with an incidental microcytosis, a high red cell count and a normal ferritin — trait, not iron deficiency.^[1]

The four-rung alpha ladder, the two-rung beta one

The whole of thalassaemia is a gene-dose problem, and the gene-dose ladder is the whole topic. Two facts unlock it: beta globin sits as two alleles on chromosome 11 (Muncie: one gene on each chromosome 11; GeneReviews locus HBB 11p15.4); alpha globin as four alleles on chromosome 16 (Muncie: two genes on each chromosome 16; GeneReviews HBA1/HBA2 16p13.3), two on each chromosome in tandem. Lose beta alleles and you climb the beta ladder (major, intermedia, trait); lose alpha alleles and you climb the four-rung alpha ladder (silent, trait, HbH, hydrops).^[1][2]

The name is a map of where it was found — Greek thalassa (sea) and haima (blood), "Mediterranean anaemia", because Cooley first described it in the children of Mediterranean immigrants. The mechanism separates it from sickle cell: sickle disease makes a normal amount of an abnormal globin (a qualitative defect); thalassaemia makes a reduced or absent amount of an otherwise normal globin (a quantitative defect). The damage is done not by the missing chain but by its unpaired partner, left to precipitate and kill the red cell from within.^[1]

Beta-thalassaemia grades by how much each allele produces — beta-0 (no chains), beta-plus (reduced), beta-plus-plus (mildly reduced) — and the pairing sets the syndrome:^[1]

• Major — usually beta-0/beta-0: no HbA; Muncie: signs appear in the second six months of life; GeneReviews: presentation between six and 24 months; fatal in early childhood without transfusion.
• Intermedia — milder anaemia that does not require regular transfusions from early childhood (GeneReviews).
• Minor (trait) — one mutated allele: asymptomatic, microcytosis with a high red cell count, normal iron, HbA2 greater than 3.5% (GeneReviews).^[1][16]

The four-rung alpha ladder is the memory device examiners love — learn it by the rung:^[1]

• One deletion — silent carrier, normal bloods, found only by family study.
• Two deletions — trait: mild microcytosis, and the trap, a NORMAL electrophoresis.
• Three deletions — HbH disease: surplus beta chains form beta-4 tetramers, a moderate chronic haemolysis.
• Four deletions — Hb Bart hydrops fetalis: surplus gamma chains form gamma-4 tetramers that cannot release oxygen; lethal in utero.^[1]

Enlarge

Then the cis-versus-trans distinction, which decides whether two carrier parents can have a hydropic fetus. A cis deletion (both alpha genes lost from one chromosome, written --/alphaalpha, the --SEA deletion of South-East Asia) means one parent can pass two deleted genes — two cis carriers risk a four-gene Hb Bart hydrops fetus. A trans deletion (one gene lost from each chromosome, -alpha/-alpha, common in Africans) never produces hydrops even when both parents are carriers. This single distinction is the backbone of prenatal counselling.^[1][5]

^{[1] [2] [9]}

The malaria belt — and why India screens every pregnancy

Thalassaemia is a tropical disease that the carrier state earned against malaria, and its burden has shifted south and east. Kattamis: worldwide distribution; most patients live in underserved areas. Agarwal: India regional carrier rates 3–40 percent.^[2][5]

The heterozygote advantage against falciparum malaria is the evolutionary reason for the geography; within high-frequency populations, founder mutations and consanguinity concentrate disease. Ethnic mutation lists (IVS1-110, IVS1-5, 619-bp deletion, --SEA) are exam-convention catalogues and are not milligrams in the fetched abstracts; what is sourced is the cis versus trans alpha-gene arrangement (Muncie: whether both defective genes are on the same or different chromosomes alters reproductive outcome) and India’s HPLC screening yield (Agarwal).^[1][5]

So the risk factors are ancestry in a high-frequency group, a family history of anaemia, splenectomy or "blood disease", and consanguinity — plus the one iatrogenic risk that dominates the adult course: transfusion, life-saving but the principal source of the iron that eventually kills.^[2]

The spare chain is the killer

Haemoglobin is a tetramer that demands balanced alpha and non-alpha chains; in thalassaemia the unpaired partner chain is what destroys the red cell. Adult HbA is two alpha plus two beta; fetal HbF is two alpha plus two gamma. Under-produce one chain and its partner is left to aggregate, oxidise and precipitate.^[1][2]

In beta-thalassaemia, alpha chains keep being made while beta chains are absent. Free alpha chains are unstable — they auto-oxidise, release haem, generate reactive oxygen species and precipitate on the inner red-cell membrane. The damaged normoblast then undergoes apoptosis: this is ineffective erythropoiesis (Kattamis: unbalanced globin-chain production leading to ineffective erythropoiesis, increased haemolysis, and deranged iron homoeostasis). The few cells that escape are then cleared by the spleen — chronic extravascular haemolysis layered on top of the intramedullary death.^[2]

In alpha-thalassaemia the surplus is non-alpha. Three deletions let spare beta chains self-assemble into beta-4 tetramers (HbH) — stable enough to circulate but functionally inert, slowly precipitating with age. Four deletions let fetal gamma chains form gamma-4 tetramers (Hb Bart), which bind oxygen so tightly they cannot release it; the fetus suffocates in its own blood and develops hydrops fetalis, lethal in utero or within hours of birth unless an intrauterine transfusion programme is in place.^[1]

Enlarge

Three downstream consequences follow, and each one explains a clinical sign you will be asked about:^[2]

1. Massive marrow expansion. Compensatory erythroid hyperplasia erodes cortical bone, producing the frontal bossing and craniofacial skeletal changes of untreated disease, plus extramedullary haematopoiesis in liver, spleen and paraspinal tissues (GeneReviews: long-bone deformities and characteristic craniofacial features).
2. Hepcidin suppression and iron loading. Ineffective erythropoiesis deranges iron homoeostasis (Kattamis); gut iron absorption rises on top of every transfused unit. There is no physiological route for iron excretion — chelation is required to remove the excess (Muncie).
3. Chronic hypoxia and end-organ failure. The anaemia, the hypermetabolic marrow and the high-output cardiac state drive growth failure, endocrine failure, pigment gallstones from chronic haemolysis, folate depletion from the erythropoietic drive — and ultimately the iron-overload cardiomyopathy that dominates late mortality.^[2]

Six to 24 months — when beta major declares itself

Beta-thalassaemia major is silent at birth and declares itself in infancy. Muncie: healthy infants have mostly HbA by about six months; pallor, irritability, growth retardation, abdominal swelling and jaundice appear in the second six months of life. GeneReviews: presentation between six and 24 months with pallor, poor weight gain, stunted growth, mild jaundice and hepatosplenomegaly. Parents describe a previously well infant who turns pale, listless and irritable, stops feeding and falls off the centiles. On examination: severe pallor with icterus, failure to thrive, and the facies of marrow expansion — frontal bossing, malar fullness, maxillary overgrowth with malocclusion, the so-called rodent or chipmunk face. The abdomen is distended by massive hepatosplenomegaly; a flow murmur and wide pulse pressure mark the chronic high-output state. Untreated, the child dies within a few years of anaemia and heart failure.^[1][2]

Intermedia has a more variable age of presentation because the anaemia does not require regular transfusions from early childhood (GeneReviews); splenomegaly and the skeletal and gallstone complications of chronic haemolysis still occur. Untransfused, these patients are paradoxically more prone to thrombosis, pulmonary hypertension, leg ulcers and extramedullary masses than well-transfused major patients, while being spared the early transfusional iron load — though gut iron still accumulates and chelation becomes necessary later.^[2]

Trait is asymptomatic and found on a routine count, an antenatal screen or a preoperative assessment — microcytosis disproportionate to a near-normal haemoglobin. The single bedside insight that earns marks: the red cell count is high or normal, the opposite of iron deficiency. A trait patient with anaemia out of proportion to trait has something else going on — investigate it.^[1]

HbH disease (three alpha deletions) is a chronic haemolytic anaemia with a broad phenotypic spectrum (GeneReviews: spleen enlargement, mild jaundice, gallstones, and acute haemolysis with infection or oxidant drugs). Named oxidant lists (sulphonamides, dapsone, primaquine, nitrofurantoin) are exam convention, not milligrams in the fetched abstracts.^[1][17]

Hb Bart hydrops fetalis presents in utero or at birth with generalised oedema, massive hepatosplenomegaly, ascites and pleural effusions — the consequence of extreme tissue hypoxia from oxygen-trapped gamma-4 tetramers. The fetus is usually stillborn or dies within hours; the mother is at markedly increased risk of pre-eclampsia, antepartum haemorrhage and difficult delivery from the enlarged placenta and fetus.^[1][5]

Atypical and late presentations are deliberate examiner favourites: the adolescent with delayed puberty and short stature (hypogonadotropic hypogonadism from iron), the young adult with new diabetes or heart failure (iron-overload cardiomyopathy), the elderly patient whose incidental microcytosis is actually iron deficiency on top of trait, and the splenectomised patient with fever and rigors (OPSI, within hours).^[2]

The microcytic fork — trait, iron deficiency, or both?

Thalassaemia is the centre of the microcytic anaemias, and a single discriminator usually settles it. The whole list, with the one feature that separates each:^[1][2]

^{[1] [2]}

The highest-yield discriminator in the topic is the red cell count. Thal trait keeps it high or normal because the marrow churns out many small cells; iron deficiency drops both haemoglobin and cell number. Add the iron studies and the HbA2 and most microcytic anaemias resolve without DNA testing.^[1]

The named trap — do NOT give iron to a trait patient. Trait keeps a normal ferritin and transferrin saturation; iron helps no one and adds load. The Mentzer index = MCV divided by RBC count: <13 supports thal trait, >13 supports iron deficiency (Yogalakshmi 2025: MI <13 for BTT screening). It is an index-level screen, not a substitute for iron studies and electrophoresis.^[15]

The face, the spleen, the drip

There is no pathognomonic bedside sign, but a focused examination builds the picture the blood count then confirms. Look along five threads — anaemia, haemolysis, marrow expansion, iron overload and prior splenectomy.^[2]

General inspection shows pallor and icterus, and — in the untreated child — growth failure and delayed puberty. The face carries frontal bossing, malar prominence and dental malocclusion; the abdomen, hepatosplenomegaly that can be massive, or a tender gallbladder from pigment stones. The cardiovascular exam typically shows a flow murmur, hyperdynamic precordium and wide pulse pressure — but switch your pattern to a gallop, raised JVP and basal crackles if iron has reached the myocardium. The skin may be bronze from haemosiderin. In the splenectomised patient, look for the scar and ask about vaccines and penicillin. Run a quick endocrine trawl: short stature, absent secondary sex characteristics, polyuria, cold intolerance.^[2]

The bedside rule: severe microcytic anaemia in an at-risk infant with hepatosplenomegaly and bony facies is beta-thalassaemia major until proven otherwise; an incidental microcytosis with a high red cell count in a well adult is trait until proven otherwise. Both are confirmed by the count and the electrophoresis, not at the bedside.^[1]

Electrophoresis first — but a normal one is the trap

Stage the investigations: count and film, iron studies and discriminant indices, then electrophoresis — and reach for DNA testing when alpha-thal is in play. In established transfusion-dependent disease the focus shifts to iron-load and end-organ surveillance.^[1][2]

Full blood count. Any severity shows microcytic hypochromic anaemia — MCV under 75 to 80 fL in disease, 70 to 80 fL in trait, MCH under 27 pg, raised RDW. The red cell count is the discriminator: high or normal in trait, often low in major from ineffective erythropoiesis. Reticulocytes are inappropriately low in beta major (precursors die in the marrow) but raised in HbH.^[1]

Mentzer and its cousins. The Mentzer index = MCV divided by RBC count: <13 thal trait, >13 iron deficiency (Yogalakshmi 2025). Green and King, England and Fraser, Srivastava, Shine and Lal perform similarly and rescue you where iron studies are unavailable. None replaces iron studies and electrophoresis.^[15]

Peripheral film. Microcytes, hypochromia, target cells, basophilic stippling; nucleated red cells, Howell-Jolly bodies (post-splenectomy) and poikilocytes in severe disease. In HbH disease, brilliant cresyl blue supravital staining produces the pathognomonic golf-ball inclusions — precipitated beta-4 tetramers.^[1]

Haemoglobin electrophoresis, HPLC or capillary zone electrophoresis is the diagnostic centrepiece for beta-thalassaemia:^[1]

^{[1] [16] [17]}

Iron studies are normal in trait — normal ferritin and transferrin saturation — the finding that excludes iron deficiency and stops the inappropriate iron prescription. In transfusion-dependent patients, EPIC titrated deferasirox on 3-month serum ferritin trends (overall ferritin −264 ng/mL).^[1][8]

DNA testing is mandatory for alpha-thalassaemia (where electrophoresis is normal), for prenatal diagnosis and for counselling at-risk couples. Gap-PCR finds the common deletions; MLPA finds the rarer ones; Sanger sequencing or ARMS-PCR identifies HBB point mutations. Pinning the family's mutations unlocks first-trimester diagnosis by chorionic villus sampling.^[5]

Skeletal survey in untreated or late-presenting major shows the hair-on-end skull, cortical thinning, metaphyseal expansion and osteoporosis of marrow expansion.^[2]

Iron-load and end-organ monitoring is the backbone of long-term care in transfusion-dependent disease:^[2]

^{[8] [10]}

Cardiac T2-star MRI is the key test in transfusion-dependent thalassaemia: a T2-star under 10 ms is the most important predictor of the development of heart failure. Serum ferritin and liver iron concentration are not adequate surrogates for cardiac iron — measure the heart directly.^[10]

Two scenarios you cannot fumble

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^[1]

Thalassaemia is chronic, but two scenarios are acute and protocol-driven: decompensated anaemia with heart failure, and overwhelming post-splenectomy infection. Get both right from memory.^[2][6]

Acute decompensated anaemia. The chronically anaemic patient has a heart adapted to chronic anaemia — resting tachycardia, high cardiac output, dilated ventricles — so transfuse cautiously and watch for volume overload. In an HbH haemolytic crisis, withdraw the oxidant trigger, give folate, transfuse cautiously and treat the underlying infection.^[10]

Overwhelming post-splenectomy infection. In the asplenic patient, fever is a medical emergency — OPSI can progress from a mild flu-like illness to fulminant sepsis and carries high mortality with delayed or inadequate treatment. The classical pathogens are encapsulated organisms. Tell the patient that any fever is an emergency and to present immediately: take cultures and start empirical broad-spectrum parenteral antibiotics without waiting for results, per your local asplenia protocol. Prevention is a three-pronged programme — education, immunoprophylaxis and chemoprophylaxis — and rising penicillin-resistant pneumococci shape both prophylaxis and treatment choices.^[13]

Transfuse, chelate, cure

Three pillars carry the transfusion-dependent patient: regular transfusion, mandatory iron chelation, and curative therapy — with folate, splenectomy and organ surveillance as supports. The goal of the first two is to suppress ineffective erythropoiesis, prevent bony deformity and allow normal growth; the goal of the third is to remove the disease entirely.^[2][6]

^{[2] [6]}

Pillar 1 — Regular transfusion keeps the disease controlled: transfusion dependence is defined by a red-cell intake of at least 150 mL/kg per year, with regimens in trials typically delivering 2 to 4 packed red-cell units per month. The goal is to control the ineffective erythropoiesis that drives marrow expansion, bony deformity and the hypermetabolic state, and to allow normal growth — transfusion with iron chelation is what transformed thalassaemia major into a chronic disease with prolonged life expectancy.^[2][8][9]

Pillar 2 — Iron chelation is mandatory. Iron accumulation is an inevitable consequence of chronic transfusion, and there are three chelators — deferiprone, deferasirox and deferoxamine, the first two oral. Dosing is individualised: deferasirox starts at 20 mg/kg/day for patients receiving 2 to 4 units per month (10 or 30 mg/kg/day for less or more intensive transfusion), with dose titration guided by 3-month serum ferritin trends and safety markers.^[8][9]

^{[8] [9] [10] [14]}

Combination chelation — deferiprone plus deferasirox, or deferiprone plus deferoxamine — is reserved for severe iron overload: in a randomised trial of 96 severely iron-loaded young beta-major patients, both combinations lowered serum ferritin and liver iron and raised cardiac T2-star at 12 months, with the all-oral deferasirox/deferiprone pair superior for cardiac T2-star, compliance and treatment satisfaction. A cardiac T2-star under 10 ms is the most important predictor of heart failure and demands intensification.^[10][11]

Pillar 3 — Curative therapy. Two options:^[2]

• Allogeneic HSCT from an HLA-identical sibling is advocated for suitable patients (Kattamis). GeneReviews: outcome tracks pretransplant hepatomegaly, liver fibrosis, and cardiac/liver iron; in children who lack these risk factors, disease-free survival is greater than 90%. The eponym “Pesaro class 1” for that low-risk triad is exam convention. Results worsen with age and iron loading.^[2][16]
• Gene therapy with betibeglogene autotemcel (beti-cel) — autologous CD34-positive cells transduced ex vivo with a lentiviral vector encoding a modified beta-globin (beta-T87Q), reinfused after myeloablation — gave transfusion independence in 20 of 22 evaluable non-beta-0/beta-0 patients (91%) (Locatelli 2022; median follow-up 29.5 months; TI = weighted average Hb ≥9 g/dL without transfusion ≥12 months). Exagamglogene autotemcel (exa-cel) is a separate CRISPR-Cas9 BCL11A-editing product — do not relabel beti-cel as exa-cel. Access is limited and expensive.^[4][2]

Adjuncts. Beyond transfusion and chelation, management is of the complications: endocrine dysfunction, bone disease, growth failure and fertility are handled by the multidisciplinary specialist team per guideline protocols.^[7]

Splenectomy is reserved for hypersplenism — the primary indication in reported beta-thalassaemia series — and is commonly combined with cholecystectomy when pigment gallstones coexist. Preoperative transfusion targets a haemoglobin of about 9 g/dL and platelets of 50,000 per microlitre. Because the asplenic state carries a lifelong infection risk, surgery is wrapped in the three-pronged prevention programme — education, immunoprophylaxis and chemoprophylaxis — with a fever-as-emergency plan for life.^[12][13]

Luspatercept. Where cure is not an option, the recombinant fusion protein luspatercept — it binds select TGF-beta superfamily ligands to enhance late erythroid maturation, dosed at 1.00 to 1.25 mg/kg — met the primary endpoint of the BELIEVE trial: a transfusion-burden reduction of at least 33 percent plus at least 2 red-cell units over weeks 13 to 24 in 21.4 percent versus 4.5 percent on placebo, and at least a 33 percent reduction in some 12-week interval in 70.5 versus 29.5 percent.^[3]

Trait, intermedia, HbH, hydrops — and pregnancy

Trait needs no treatment — the job is to dodge three errors: mistaking it for iron deficiency and prescribing iron (overload, no benefit); missing a coexisting iron deficiency (treat the iron, not the trait); and forgetting to counsel carrier couples about reproductive risk. A trait patient with anaemia out of proportion to trait has something else going on — find it.^[1]

Intermedia (NTDT) is managed expectantly: folate, growth and iron-load monitoring, intermittent transfusion for pregnancy, infection or growth failure, and chelation when liver iron or ferritin rises even without regular transfusion (because gut absorption is increased by the expanded erythroid mass). These patients carry more thrombosis, pulmonary hypertension, leg ulcers, extramedullary masses and pigment stones than well-transfused major patients, and those complications drive the plan as much as the anaemia.^[2]

HbH disease. Folate, avoid oxidant drugs (GeneReviews: infection or oxidant exposure can trigger acute haemolysis), transfuse in haemolytic crisis, splenectomise for severe hypersplenism.^[1][17]

Hb Bart hydrops fetalis is incompatible with life (Muncie: usually fatal hydrops; GeneReviews: untreated death in embryonic life or the neonatal period). Muncie: whether both defective alpha genes are on the same or different chromosomes alters reproductive outcome — the cis (--/αα) arrangement can yield a four-gene fetus. Offer counselling and prenatal diagnosis (Muncie: chorionic villus sampling with PCR). The named --SEA deletion is exam-convention geography, not a milligram in the fetched abstracts.^[1][17]

Pregnancy. Trait tolerates pregnancy well; the priority is to screen the partner and offer prenatal diagnosis if both are carriers. GeneReviews: individuals with β-thalassaemia major often need increased transfusions in pregnancy; iron chelation should not be given during fetal organogenesis and may be started in the second trimester if maternal iron overload requires it. Keep the pretransfusion Hb in the sourced range (Muncie >9.5 g/dL; GeneReviews 9.5–10.5 g/dL). Cardiac T2-star thresholds other than Pennell’s <10 ms HF predictor are not in the fetched set.^[16][1][10]

The splenectomised patient. Lifelong risk means lifelong vigilance: education, complete immunisation and antibiotic chemoprophylaxis, plus a fever-as-emergency plan.^[13]

Where thalassaemia kills — iron and infection

Complications fall into three baskets — the disease itself, the transfusion-and-iron load, and the splenectomy — and examiners test the lethal one (iron-overload cardiomyopathy) again and again.^[2]

Disease-related: growth failure and delayed puberty, bony deformity and osteoporotic fractures, extramedullary masses (paraspinal, pleural, intracranial), leg ulcers (especially intermedia), pigment gallstones, folate deficiency, hypersplenism, and — in NTDT — a prothrombotic state with venous thromboembolism and pulmonary hypertension.^[2]

Transfusion- and iron-related dominate the adult course:^[2]

Splenectomy-related: overwhelming post-splenectomy infection (encapsulated organisms — pneumococcus, meningococcus, Haemophilus influenzae type b — and Capnocytophaga), thrombocytosis with venous thromboembolism, and pulmonary hypertension.^[6]

The classic pitfalls that cost marks and lives: misdiagnosing trait as iron deficiency and giving iron; missing alpha-thal trait because the electrophoresis is normal (a normal electrophoresis in a microcytic patient of high-risk ancestry is alpha-thal trait until DNA says otherwise); failing to chelate early so cardiac iron accumulates silently; trusting a normal ferritin to exclude cardiac iron (cardiac and hepatic iron discordance is common — measure the T2-star); and underestimating a fever in a splenectomised patient.^[1][2]

Survival with transfusion and chelation

Untreated beta-thalassaemia major is fatal in early childhood (Muncie). Conservative transfusion plus chelation has transformed the natural history into a chronic disease with prolonged life expectancy (Kattamis). Muncie 2009: persons with beta-thalassaemia major often die from cardiac complications of iron overload by 30 years of age when overload is untreated. Pennell: heart failure is the most common cause of death in thalassaemia major and primarily results from cardiac iron accumulation: a cardiac T2-star under 10 ms is the most important predictor of its development, and intensive chelation can reverse even severe loading if started in time.^[1][2][10]

HSCT in low-risk children (no hepatomegaly, limited fibrosis and iron) yields disease-free survival greater than 90% (GeneReviews); outcome falls with age and iron loading. Gene therapy with betibeglogene autotemcel produced transfusion independence in 20/22 (91%) evaluable non-β0/β0 patients at median 29.5 months (Locatelli).^[4][16]

Patients need lifelong specialist haematology follow-up with a multidisciplinary team — cardiology for MRI and failure, endocrinology for hormones and bone, hepatology for iron-related liver disease, reproductive medicine for fertility, dentistry for maxillary complications. A structured adolescent transition from paediatric to adult services prevents the loss-to-follow-up that drives late mortality. Counsel about genetic risk to siblings and offspring, and offer carrier screening and prenatal diagnosis.^[2][6]

Children, pregnancy, the elderly trait, the asplenic

Children. Transfusion and chelation follow the same principles, weight-based: deferasirox dosing starts from transfusional iron intake (20 mg/kg/day on 2 to 4 units per month) and is titrated on 3-monthly ferritin trends and safety markers; deferasirox is not registered under 2 years of age, where deferoxamine is used instead. Growth, pubertal staging and bone age are checked every visit. HSCT is best done early, before iron and hepatomegaly erode survival.^[8][9]

Pregnancy. Trait is well-tolerated; screen the partner, offer prenatal diagnosis if both carry. In major, plan conception in a multidisciplinary clinic: keep Hb in the sourced transfusion range (>9.5 g/dL / 9.5–10.5 g/dL), do not chelate during fetal organogenesis, and assess cardiac status (Pennell: T2-star <10 ms predicts heart failure).^[16][1][10]

The elderly trait patient. Incidental microcytosis in an older adult is often both trait and iron deficiency — iron studies still guide, and occult blood loss must not be missed. Trait itself needs no treatment at any age.^[1]

The immunocompromised and asplenic patient. Aggressive fever management, complete vaccines and penicillin prophylaxis are non-negotiable; heavily pre-treated or immunosuppressed patients get irradiated, CMV-matched components as locally indicated.^[6]

At-risk ethnicities (Mediterranean, Middle Eastern, South Asian, South-East Asian) are the target of carrier screening — school-leaving or premarital, and universal antenatal — so carrier couples are found before an affected child is born.^[5][6]

The trials and the guidelines

The Thalassaemia International Federation (TIF) Guidelines — fourth edition, 2021, for transfusion-dependent thalassaemia — set out clinical practice recommendations across transfusion, chelation and the management of complications, delivered by multidisciplinary teams in specialist centres.^[7]

Landmark trials:

^{[3] [4] [3] [4]}

Regional deltas. In India, Agarwal documents targeted antenatal HPLC screening (6.8% carriers among 33,270 screened) and Dolai/ISHBT 2026 set national best-practice recommendations spanning transfusion, chelation, HSCT and prevention. TIF 2021 (Farmakis summary) is the international TDT practice document. Locatelli 2022 is the sourced beti-cel efficacy paper; licensing dates are not milligrams in the fetched set. Kattamis: worldwide inequality of access, because most patients live in underserved areas.^[2][5][6][7]

Mnemonics and one-liners

The high-yield one-liners that win marks:

^[1]

• Beta = HBB on chromosome 11 (two alleles; GeneReviews 11p15.4); alpha = HBA on chromosome 16 (four alleles; GeneReviews 16p13.3). This pair of facts explains the entire clinical spectrum.^[1][16][17]
• Alpha-thal trait has a NORMAL Hb electrophoresis — raised HbA2 is beta trait only. The single commonest thalassaemia trap.
• Thalassaemia trait = microcytosis with a HIGH RBC count and normal iron/ferritin; do NOT give iron.
• Beta major presents between six and 24 months (GeneReviews); Muncie: second six months of life. GeneReviews table: HbF up to 95%, HbA typically near 0%.
• Hb Bart hydrops fetalis (four alpha deletions) is incompatible with life — counsel parents and offer prenatal diagnosis; Muncie notes increased maternal toxemia and postpartum bleeding risk.
• Heart failure from cardiac iron is the leading cause of death — chelation is mandatory (deferasirox 20 to 40 mg/kg/day or deferiprone 75 to 100 mg/kg/day oral).^[9][10]
• Mentzer index = MCV / RBC count — <13 thalassaemia trait, >13 iron deficiency (Muncie and Yogalakshmi).^[1][15]
• Curative: matched-sibling HSCT (GeneReviews DFS greater than 90% in low-risk children); beti-cel 20/22 TI (Locatelli).
• Avoid oxidant drugs in HbH disease (GeneReviews); named agent lists are exam convention.
• Splenectomy preparation is non-negotiable: Muncie delays surgery until at least four years and gives pneumococcal vaccine at least one month before; Brigden: education, immunoprophylaxis, chemoprophylaxis.
• Cardiac T2-star is the prognostic test: under 10 ms is the strongest predictor of heart failure — a normal ferritin does NOT exclude cardiac iron.^[10]

The mantra

Chelate from the start — the heart is where thalassaemia kills.^[1][2]

Ward-round test — three stems, thirty seconds each

Stem 1 — the normal-electrophoresis microcytosis (answer)ShowHide

A 26-year-old well woman of South-East Asian ancestry is found on a booking blood count to have Hb 118 g/L, MCV 72 fL, RBC count 6.2 (high), ferritin normal. The Hb electrophoresis is entirely normal — HbA2 not raised. The GP plans to start oral iron "to be safe". What is the diagnosis, and what do you advise? Model: This is alpha-thalassaemia trait — the classic trap. A microcytic patient of high-risk ancestry with a high RBC count, normal ferritin and a NORMAL electrophoresis is alpha-thal trait until DNA testing says otherwise; a raised HbA2 is beta trait only. Do NOT prescribe iron — it adds load without benefit. Confirm with gap-PCR or MLPA if needed, and counsel about reproductive risk: if her partner also carries a cis (--) alpha deletion, a future fetus is at risk of Hb Bart hydrops.^[1][5]

Stem 2 — the splenectomised patient with fever (answer)ShowHide

A 19-year-old with transfusion-dependent beta-thalassaemia major, splenectomised at age 6, phones in at midnight with fever, rigors and myalgia. He is compliant with penicillin prophylaxis. What is the diagnosis and the first-hour bundle? Model: This is overwhelming post-splenectomy infection (OPSI) until proven otherwise — a medical emergency that can progress from flu-like illness to fulminant sepsis, with high mortality when treatment is delayed. Take cultures, then start empirical broad-spectrum parenteral antibiotics immediately without waiting for results, and support aggressively with fluids, vasopressors and ICU as needed. Narrow once an organism is identified. The standing instruction to every asplenic patient is that any fever is an emergency.^[13]

Stem 3 — the pale nine-month-old (answer)ShowHide

A nine-month-old boy of Greek ancestry is pale and listless, off his feeds, with frontal bossing and a spleen crossing the midline. Hb 55 g/L, MCV 60 fL; Hb electrophoresis shows HbF dominating at 85 percent with absent HbA. Name the diagnosis, the transfusion target and the long-term obligation. Model: This is beta-thalassaemia major — GeneReviews presentation window six to 24 months; Muncie second six months of life. Transfuse with regular packed red cells (Muncie: keep Hb higher than 9.5 g/dL; DEEP-2 TDT enrolment at least 150 mL/kg per year; EPIC typically 2 to 4 units per month) to control ineffective erythropoiesis, halt marrow expansion and allow normal growth. The long-term obligation is mandatory iron chelation — oral deferasirox (20 to 40 mg/kg/day) or deferiprone (75 to 100 mg/kg/day), or subcutaneous deferoxamine — with cardiac MRI T2-star surveillance, because a T2-star under 10 ms predicts heart failure and heart failure is the leading cause of death. Counsel the parents on reproductive risk and offer prenatal diagnosis in future pregnancies; a matched-sibling HSCT in low-risk children has DFS greater than 90% (GeneReviews).^{[1][8][9][10][16]}

References17ShowHide

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