Beta thalassemia

Beta-thalassemia
Other names	Microcytemia, beta type[1]
Beta thalassemia genetics, the picture shows one example of how beta thalassemia is inherited. The beta globin gene is located on chromosome 11. A child inherits two beta globin genes (one from each parent).
Specialty	Hematology
Types	Thalassemia minor, intermediate and major[2]
Causes	Mutations in the HBB gene[1]
Diagnostic method	DNA analysis[3]
Treatment	Depends on type (see types)

Beta thalassemias (β thalassemias) are a group of inherited blood disorders. They are forms of thalassemia caused by reduced or absent synthesis of the beta chains of hemoglobin that result in variable outcomes ranging from severe anemia to clinically asymptomatic individuals. Global annual incidence is estimated at one in 100,000.^[4] Beta thalassemias occur due to malfunctions in the hemoglobin subunit beta or HBB. The severity of the disease depends on the nature of the mutation.^[5]

The body's inability to construct new beta-chains leads to the underproduction of HbA (adult hemoglobin).^[6] The imbalance of alpha to beta globin chains leads to ineffective erythropoiesis, increased hemolysis, and deranged iron homeostasis.^[7] Patients requiring repeated blood transfusions may develop severe problems associated with iron overload.^[8]