A 4-year-old girl from Kerala presents with mild jaundice, splenomegaly, and a hemoglobin of 9.2 g/dL. Her parents are consanguineous. Peripheral blood smear shows target cells and hypochromic microcytic RBCs. Hemoglobin electrophoresis reveals HbA (60%), HbA2 (4%), and HbF (36%). Osmotic fragility test is normal. What is the most likely diagnosis?

Explanation

## Diagnosis: Beta-Thalassemia Intermedia ### Clinical Presentation **Key Point:** Beta-thalassemia intermedia presents with **moderate anemia (Hb 7–10 g/dL)**, **splenomegaly**, and **jaundice** without requiring regular transfusions. It is clinically intermediate between trait and major forms. ### Diagnostic Criteria | Feature | Beta-Thalassemia Intermedia | Beta-Thalassemia Trait | Beta-Thalassemia Major | | --- | --- | --- | --- | | **Hemoglobin level** | 7–10 g/dL | 10–12 g/dL | <7 g/dL | | **Transfusion requirement** | Occasional or none | None | Regular (monthly) | | **HbA percentage** | 5–30% | 80–95% | Absent (0%) | | **HbA2 percentage** | 2–5% | 3–5% | 2–7% | | **HbF percentage** | 10–50% | <1% | 70–90% | | **Splenomegaly** | Present | Absent | Present | | **Jaundice** | May be present | Absent | Present | | **Skeletal deformities** | Absent or mild | Absent | Present | ### Hemoglobin Electrophoresis Interpretation **High-Yield:** The pattern of **HbA 60%, HbA2 4%, HbF 36%** is characteristic of beta-thalassemia intermedia. The presence of significant HbA (not absent as in major) combined with elevated HbF distinguishes it from trait form. ### Pathophysiology 1. Compound heterozygous or homozygous mutations with some residual β-globin production 2. Moderate imbalance of α and β chains → some hemolysis but less severe than major 3. Splenomegaly from extramedullary hematopoiesis and hemolysis 4. Jaundice from chronic hemolysis 5. **Normal osmotic fragility** excludes hereditary spherocytosis ### Clinical Pearl **Consanguineous parents** increase the likelihood of autosomal recessive disorders like thalassemia. The **normal osmotic fragility test** is crucial to exclude hereditary spherocytosis, which also presents with jaundice and splenomegaly but has a different RBC morphology and electrophoresis pattern. ### Differential Diagnosis **Warning:** Do not confuse with beta-thalassemia trait (heterozygous), which has: - Mild or no anemia (Hb 10–12 g/dL) - Minimal or absent symptoms - HbA2 elevated but HbF normal or minimally elevated - No transfusion requirement [cite:Robbins 10e Ch 13]