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Beta Thalassemia
Aka: Beta Thalassemia, Cooley's Anemia
- See Also
- Thalassemia
- Epidemiology: Ethnicity
- Southern Italy and Mediterranean islands (0.1% Incidence)
- Central Africa
- Southeast Asia
- Pathophysiology
- See Hemoglobin Production
- Autosomal Recessive trait affecting single gene on each of the two Chromosome 11
- Results in decrease of absence of Hemoglobin beta chains and excess of alpha chains
- Types
- Beta Thalassemia Trait
- One gene defect on Chromosome 11 (Heterozygote)
- Typically asymptomatic
- Beta Thalassemia Intermedia
- Two gene defect on Chromosome 11
- Mild to moderate decrease in beta globin synthesis
- Moderate symptoms (less than in Beta Thalassemia Major) - see below
- Beta Thalassemia Major (Cooley's Anemia)
- Two gene defect on Chromosome 11
- Severe decrease in beta globin synthesis
- Severe symptoms (see below)
- Onset of symptoms by 6 months of age after Hemoglobin F (fetal Hemoglobin) levels fall
- Symptoms
- Irritability
- Signs
- Abdominal Distention
- Pallor
- Splenomegaly
- Impaired Growth
- Labs
- See Thalassemia
- Hemolytic Anemia
- Typically more severe Anemia than with Alpha Thalassemia
- Diagnosis
- Hemoglobin Electrophoresis
- Management: Beta Thalassemia Major
- Periodic Blood Transfusions to keep Hemoglobin >9.5 g/dl
- May be required as young as 6 months
- Concurrent use of an iron chelator starting at 5 to 8 years old
- Deferoxamine (Desferal) SQ/IV
- Deferasirox (Exjade) Orally
- Bone Marrow Transplantation
- Curative of Beta Thalassemia when performed in childhood in low risk patients
- Splenectomy in cases of hypersplenism
- Indicated after age 4
- Management: General
- Folic Acid 1 gram orally daily
- Complications
- Untreated infants
- Growth Delay
- Skeletal disorders
- Jaundice
- Hypersplenism (requires splenectomy)
- High Cardiac Risk Factor
- Increased survival when Serum Ferritin <2500 ng/ml (assumes normal liver function)
- Hypercoagulable state (especially after splenectomy)
- Consider Perioperative Anticoagulation
- Avoid exacerbating Hypercoagulable state (e.g. avoid OCPs in women)
- Osteoporosis
- Treatment complications
- Iron overload (Hemochromatosis) related to frequent transfusions
- Prevention
- Preconception Genetic Counseling for parents with Thalassemia
- Chorionic Villus Sampling can diagnose Beta Thalassemia in first trimester
- Preimplantation Genetic Testing can predict Beta Thalassemia prior to in vitro fertilization
- Prognosis: Life Expectancy
- Beta Thalassemia Trait: Normal Life Expectancy
- Beta Thalassemia Major: 17-30 years (due to iron overload complications)
- References
- Muncie (2009) Am Fam Physician 80(4): 339-44 [PubMed]
- Rund (2005) N Engl J Med 353(11):1135-46 [PubMed]