Hemoglobin

Beta Thalassemia

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Beta Thalassemia, Cooley's Anemia

  • See Also
  • Epidemiology
  • Ethnicity
  1. Southern Italy and Mediterranean islands (0.1% Incidence)
  2. Central Africa
  3. Southeast Asia
  • Pathophysiology
  1. See Hemoglobin Production
  2. Autosomal Recessive trait affecting single gene on each of the two Chromosome 11
  3. Results in decrease of absence of Hemoglobin beta chains and excess of alpha chains
  • Types
  1. Beta Thalassemia Trait
    1. One gene defect on Chromosome 11 (Heterozygote)
    2. Typically asymptomatic
  2. Beta Thalassemia Intermedia
    1. Two gene defect on Chromosome 11
    2. Mild to moderate decrease in beta globin synthesis
    3. Moderate symptoms (less than in Beta Thalassemia Major) - see below
  3. Beta Thalassemia Major (Cooley's Anemia)
    1. Two gene defect on Chromosome 11
    2. Severe decrease in beta globin synthesis
    3. Severe symptoms (see below)
    4. Onset of symptoms by 6 months of age after Hemoglobin F (fetal Hemoglobin) levels fall
  • Symptoms
  1. Irritability
  • Signs
  1. Abdominal Distention
  2. Pallor
  3. Splenomegaly
  4. Impaired Growth
  • Labs
  1. See Thalassemia
  2. Hemolytic Anemia
    1. Typically more severe Anemia than with Alpha Thalassemia
  • Diagnosis
  1. Hemoglobin Electrophoresis
  • Management
  • Beta Thalassemia Major
  1. Periodic Blood Transfusions to keep Hemoglobin >9.5 g/dl
    1. May be required as young as 6 months
    2. Concurrent use of an iron chelator starting at 5 to 8 years old
      1. Deferoxamine (Desferal) SQ/IV
      2. Deferasirox (Exjade) Orally
  2. Bone Marrow Transplantation
    1. Curative of Beta Thalassemia when performed in childhood in low risk patients
  3. Splenectomy in cases of hypersplenism
    1. Indicated after age 4
  • Management
  • General
  1. Folic Acid 1 gram orally daily
  • Complications
  1. Untreated infants
    1. Growth Delay
    2. Skeletal disorders
    3. Jaundice
  2. Hypersplenism (requires splenectomy)
  3. High Cardiac Risk Factor
    1. Increased survival when Serum Ferritin <2500 ng/ml (assumes normal liver function)
  4. Hypercoagulable state (especially after splenectomy)
    1. Consider Perioperative Anticoagulation
    2. Avoid exacerbating Hypercoagulable state (e.g. avoid OCPs in women)
  5. Osteoporosis
  6. Treatment complications
    1. Iron overload (Hemochromatosis) related to frequent transfusions
  • Prevention
  1. Preconception Genetic Counseling for parents with Thalassemia
  2. Chorionic Villus Sampling can diagnose Beta Thalassemia in first trimester
  3. Preimplantation Genetic Testing can predict Beta Thalassemia prior to in vitro fertilization
  1. Beta Thalassemia Trait: Normal Life Expectancy
  2. Beta Thalassemia Major: 17-30 years (due to iron overload complications)