Thalassemia: Difference between revisions
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===ɑ-Thalassemia Carrier and Trait=== | ===ɑ-Thalassemia Carrier and Trait=== | ||
* | *No clinical symptoms or physical findings | ||
* | *Microcytic RBCs and normal Hb level | ||
===Hemoglobin H Disease (HbH disease)=== | ===Hemoglobin H Disease (HbH disease)=== | ||
* | *One ɑ-globin chain gene is still functional | ||
* | *Typically presents in neonatal period with severe hypochromic anemia | ||
* | *Hypochromic, microcytic anemia with jaundice and hepatosplenomegaly | ||
* | *May not require regular transfusions | ||
* | *Tranfusions may be necessary in setting of increased oxidative stress or infection which may precipitate hemolysis | ||
* | *Note that alpha thalassemia major (Hb Bart) results in hydrops fetalis, and thus is not an adult disease process | ||
===β-Thalassemia Minor (β-Thalassemia Trait)=== | ===β-Thalassemia Minor (β-Thalassemia Trait)=== | ||
* | *Heterozygous for β-globin mutation | ||
* | *Mild microcytic anemia | ||
* | *Splenomegaly uncommon | ||
* | *Microcytosis, hypochromia, basophilic stippling on blood smear | ||
* | *Co clinical symptoms | ||
===β-Thalassemia Major (Cooley Anemia)=== | ===β-Thalassemia Major (Cooley Anemia)=== | ||
* | *Both β-globin genes defective; β-globin chain production severely impaired | ||
* | *Typically presents >6mos of life (HbF production replaced with β-globin to form HbA) | ||
* | *Hepatosplenomegaly, jaundice, expansion of erythroid marrow causing bone changes and osteoporosis, susceptible to infection | ||
* | *Severe anemia requiring regular and lifelong blood transfusions | ||
** | **Iron overload secondary to frequent transfusions is etiology of most of morbidity and mortality | ||
* | *Low MCV with microcytic and hypochromic RBC | ||
===Sickle Cell-β-Thalassemia Disease=== | ===Sickle Cell-β-Thalassemia Disease=== | ||
* | *Gene for sickle Hb is inherited from one parent and gene for β-thalassemia is inherited from the other parent | ||
*1 per 1600 African American births | *1 per 1600 African American births | ||
* | *Severity depends on type of β-thalassemia gene inherited | ||
**80-90% inherit β-thalassemia gene that has some normal β-chain production; these patients have mild hemolytic anemia with near-normal Hb levels, few crises | **80-90% inherit β-thalassemia gene that has some normal β-chain production; these patients have mild hemolytic anemia with near-normal Hb levels, few crises | ||
**10-20% inherit β-thalassemia gene that produces no-chains; these patients have severe hemolytic anemia and vaso-occlusive symptoms | **10-20% inherit β-thalassemia gene that produces no-chains; these patients have severe hemolytic anemia and vaso-occlusive symptoms | ||
Revision as of 23:11, 22 September 2018
Background
- A group of hereditary disorders resulting in microcytic, hypochromic, hemolytic anemia
- Most common in Mediterranean, Middle Eastern, African and Southeast Asian population
Clinical Features
- Categorized depending on globin chain affected or the abnormal Hb produced
- β-globin gene mutations cause β-thalassemia; ɑ-globin mutations cause ɑ-thalassema
ɑ-Thalassemia Carrier and Trait
- No clinical symptoms or physical findings
- Microcytic RBCs and normal Hb level
Hemoglobin H Disease (HbH disease)
- One ɑ-globin chain gene is still functional
- Typically presents in neonatal period with severe hypochromic anemia
- Hypochromic, microcytic anemia with jaundice and hepatosplenomegaly
- May not require regular transfusions
- Tranfusions may be necessary in setting of increased oxidative stress or infection which may precipitate hemolysis
- Note that alpha thalassemia major (Hb Bart) results in hydrops fetalis, and thus is not an adult disease process
β-Thalassemia Minor (β-Thalassemia Trait)
- Heterozygous for β-globin mutation
- Mild microcytic anemia
- Splenomegaly uncommon
- Microcytosis, hypochromia, basophilic stippling on blood smear
- Co clinical symptoms
β-Thalassemia Major (Cooley Anemia)
- Both β-globin genes defective; β-globin chain production severely impaired
- Typically presents >6mos of life (HbF production replaced with β-globin to form HbA)
- Hepatosplenomegaly, jaundice, expansion of erythroid marrow causing bone changes and osteoporosis, susceptible to infection
- Severe anemia requiring regular and lifelong blood transfusions
- Iron overload secondary to frequent transfusions is etiology of most of morbidity and mortality
- Low MCV with microcytic and hypochromic RBC
Sickle Cell-β-Thalassemia Disease
- Gene for sickle Hb is inherited from one parent and gene for β-thalassemia is inherited from the other parent
- 1 per 1600 African American births
- Severity depends on type of β-thalassemia gene inherited
- 80-90% inherit β-thalassemia gene that has some normal β-chain production; these patients have mild hemolytic anemia with near-normal Hb levels, few crises
- 10-20% inherit β-thalassemia gene that produces no-chains; these patients have severe hemolytic anemia and vaso-occlusive symptoms
Differential Diagnosis
Anemia
RBC Loss
- Hemorrhage
RBC consumption (Destruction/hemolytic)
- Hereditary
- Acquired
- Microangiopathic Hemolytic Anemia (MAHA)
- Autoimmune hemolytic anemia
Impaired Production (Hypochromic/microcytic)
- Iron deficiency
- Anemia of chronic disease
- Thalassemia
- Sideroblastic anemia
Aplastic/myelodysplastic (normocytic)
Megaloblastic (macrocytic)
- Vitamin B12/folate deficiency
- Drugs (chemo)
- HIV
Evaluation
- CBC
- CMP
- Blood smear
- Reticulocyte count
- LDH
- Haptoglobin
Management
- Identify and discontinue precipitating agent
- Supportive care
- Blood transfusions for severe anemia
Disposition
See Also
External Links
References
- Tintinalli's Emergency Medicine 7th Edition, pg1486-7