Updated: 2/7/2020

Diamond-Blackfan Anemia

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Snapshot
  • A 2-month-old girl presents to the emergency department with lethargy. She was born to a 28-year-old mother at 37 weeks gestation via an uncomplicated spontaneous vaginal delivery. Physical examination is notable for conjunctival pallor and triphalangeal thumbs. Laboratory testing is remarkable for a macrocytic anemia, reticulocytopenia, and elevated erythrocyte adenosine deaminase activity.
Introduction
  • Overview
    • a congenital impairment in erythrocyte formation that usually presents in infancy
      • results in a pure red cell aplasia, which is an isolated anemia with reticulocytopenia
    • characteristic findings include
      • normochromic and usually macrocytic anemia
      • reticulocytopenia
      • decreased or absent erythroid precursors in the bone marrow
      • elevated erythrocyte adenosine deaminase
      • increased hemoglobin F
      • presence of red blood cell i antigen
  • Epidemiology
    • demographics
      • ~90% of patients are diagnosed within the first year of life
      • ~35% of patients are diagnosed within the first month of life
  • Pathophysiology
    • believed to be due to genetic mutations impairing ribosome synthesis
      • through unclear mechanisms, this results in activation of tumor protein p53, which impairs erythropoiesis
  • Genetics
    • inheritence pattern
      • usually autosomal dominant
    • mutations
      • impaired ribosome synthesis
  • Associated conditions
    • increased risk for malignancies
      • acute myelogenous leukemia
      • myelodysplastic syndrome
      • solid tumors (e.g., colon cancer)
  • Prognosis
    • 40% of patients become steroid dependent
    • 40% of patients are blood transfusion dependent
    • spontaneous remission has been reports in ~25% of patients
Presentation
  • Symptoms
    • fatigue or lethargy
    • poor feeding
  • Physical exam
    • congenital abnormalities (30-50% of patients)
      • craniofacial abnormalities
        • hypertelorism
        • microcephaly
      • ophthalmic abnormalities
        • congenital cataracts or glaucoma
      • neck anomalies
        • scapular elevation
        • Turner-like appearance
          • vertebral fusion with flaring of the trapezius muscles
      • cardiac and pulmonary anomalies
        • atrial and ventricular septal defects
      • thumb abrnormalities
        • triphalangeal thumb
Studies
  • Serum labs
    • isolated macrocytic anemia
      • white blood cells and platelets are typically normal
    • reticulocytopenia
    • elevated hemoglobin F
    • elevated erythrocyte adenosine deaminase activity
  • Invasive studies
    • bone marrow examination
      • normal overall cellularity
      • decreased or absent erythroid precursors
Differential
  • Transient erythroblastopenia of childhood
    • differentiating factors
      • an acquired anemia typically secondary to a viral illness
      • absent congenital anomalies
      • normal erythrocyte adenosine deaminase activity
      • absent red blood cell I antigen
Treatment
  • Medical
    • corticosteroids
      • indication
        • first-line treatment option that is preferably given in infants at least 6-12 months of age
      • comments
        • reticulocytes typically begin to appear and increase within 1-2 weeks
    • blood transfusion
      • indication
        • first-line treatment in patients who are not responding to corticosteroids or are not candidates for corticosteroids
Complications
  • Iron overload from blood transfusions
  • Hyperglycemia from corticosteroids
  • Anemia
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