DiamondBlackfan

Diamond-Blackfan anemia (DBA) is a rare congenital disorder characterized by failure of erythroid progenitors in the bone marrow, leading to macrocytic anemia that typically presents in infancy or early childhood. Reticulocytopenia is common, while white blood cell and platelet counts are usually normal. Many patients have elevated fetal hemoglobin, and some exhibit growth retardation or craniofacial and limb anomalies, though these features are not universal.

Genetics play a major role in DBA. Most cases are autosomal dominant with variable penetrance, and a substantial portion arise de novo. Mutations in genes encoding ribosomal proteins are responsible for many instances; the most frequently affected gene is RPS19, followed by RPS24, RPS17, RPS7, RPS10, RPS26, RPL5, RPL11, RPL35A and other ribosomal protein genes. In some patients, mutations in other ribosome biogenesis or regulatory genes are identified. Genetic testing confirms the diagnosis in a significant subset of cases and aids family counseling.

Pathophysiology involves defective ribosome biogenesis due to mutant ribosomal proteins, which impairs erythropoiesis and may activate p53-mediated apoptosis of erythroid progenitors. DBA is considered a ribosomopathy and shares features with other disorders caused by impaired ribosome production.

Diagnosis is based on clinical presentation, hematologic findings, and bone marrow analysis showing erythroid hypoplasia with preserved myeloid and megakaryocytic lines. Macrocytosis and low reticulocyte counts are typical, and fetal hemoglobin levels are often elevated. Genetic testing supports diagnostic confirmation and informs inheritance patterns.

Treatment and prognosis: First-line therapy is corticosteroids, which induce hematologic responses in a substantial portion of patients and can reduce transfusion needs. Nonresponders or relapsed cases may require chronic red blood cell transfusions with iron chelation. Hematopoietic stem cell transplantation offers a potential cure for severe, transfusion-dependent DBA. Long-term risks include iron overload and an increased risk of myelodysplastic syndrome or leukemia, necessitating ongoing monitoring.

History: The condition is named after Louis K. Diamond and Louise T. Blackfan, who first described the syndrome in the 1930s.