Categorized depending on globin chain affected or the abnormal Hb produced
β-globin gene mutations cause β-thalassemia; ɑ-globin mutations cause ɑ-thalassema
β-globin gene mutations cause β-thalassemia; ɑ-globin mutations cause ɑ-thalassema
No clinical symptoms or physical findings
Microcytic RBCs and normal Hb level
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
Transfusions may be necessary in setting of increased oxidative stress or infection which may precipitate hemolysis
Note that alpha<unk>  major (Hb Bart) results in hydrops fetalis, and thus is not an adult disease process
Heterozygous for β-globin mutation
Mild microcytic anemia
Splenomegaly uncommon
Microcytosis, hypochromia, basophilic stippling on blood smear
Co clinical symptoms
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
Iron overload secondary to frequent transfusions is etiology of most of morbidity and mortality
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
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
Thalassemia
Hemorrhage
Myelophthistic anemia
Hereditary
Hereditary spherocytosis
Sickle cell disease
Paroxysmal nocturnal hemoglobinuria
Glucose-6-phosphate deficiency