**Question:** A 12 months old girl of Punjabi parents developed pallor since 3 months of age. One unit of blood transfusion was done at 5 months of age. Now presents with pallor, on examination hepatosplenomegaly. Hemoglobin was 3.8 gm/dl, MCV= 68, MCH = 19. Peripheral smear showed schistocytes. Bone marrow examination show erythroid hyperplasia. Diagnosis is:

A. Sickle cell disease
B. Thalassemia
C. Diamond Blackfan anemia
D. Pyruvate kinase deficiency

**Core Concept:** Diamond Blackfan Anemia (DBA) is a rare congenital bone marrow failure disorder characterized by red blood cell (RBC) hypoplasia and mild to severe anemia. It is typically diagnosed in infants or young children.

**Why the Correct Answer is Right:** The correct answer is C. Diamond Blackfan Anemia (DBA), as it fits all the clinical and laboratory findings mentioned:

- The patient presents with pallor since 3 months of age, followed by a blood transfusion at 5 months of age, and now has hepatosplenomegaly, low hemoglobin levels, low mean corpuscular volume (MCV), low mean corpuscular hemoglobin (MCH), and schistocytes on peripheral smear.
- The bone marrow examination shows erythroid hyperplasia, which is a hallmark feature of DBA.

**Why Each Wrong Option is Incorrect:**

A. Sickle cell disease: This is a separate genetic disorder characterized by hemoglobin S, causing red blood cell (RBC) abnormality, not related to bone marrow failure or RBC hypoplasia.

B. Thalassemia: This is a group of inherited disorders characterized by reduced production of hemoglobin A, causing microcytic hypochromic RBCs, not bone marrow failure or RBC hypoplasia.

D. Pyruvate kinase deficiency: This is a genetic disorder affecting RBC glycolytic enzyme, causing hemolysis, not bone marrow failure or RBC hypoplasia.

**Clinical Pearl:** Diamond Blackfan anemia is a rare congenital bone marrow failure disorder that affects predominantly infants and children. It is characterized by normochromic macrocytic anemia, bone marrow hypoplasia, and increased erythroid precursors. The disease is often associated with ribosomal mutations affecting ribosomal biogenesis, leading to abnormal RBC development and ineffective erythropoiesis.