A 6-year-old boy presents with intermittent jaundice and splenomegaly. His father had a splenectomy in childhood for a similar problem. Smear shows spherocytes without Coombs positive hemolysis. Reticulocyte count is 6%. Which test best confirms the diagnosis?

• A Ham acidified serum lysis test
• B Osmotic fragility test showing increased fragility ✓
• C Sucrose hemolysis test
• D Schilling test

Explanation

Hereditary spherocytosis is the commonest inherited hemolytic anemia in northern Europeans and shows autosomal dominant inheritance in most families. Spherocytes have reduced surface area to volume ratio and lyse in hypotonic saline sooner than normal cells, so increased osmotic fragility confirms the diagnosis. The Ham and sucrose tests diagnose paroxysmal nocturnal hemoglobinuria, and the Schilling test assesses vitamin A12 absorption.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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