Increased levels of HBA2 are characteristic of?
Increased levels of hemoglobin A2 (Hb d) are characteristic of b Thalassemia trait. Thalassemia syndromes are genetic disorders characterized by diminished synthesis of globin chains due to globin gene defects. Thalassemias are named according to the deficient chain. Thus, b thalassemia is characterized by deficient synthesis of the b chain, which is a component of hemoglobin A (Hb A). In an attempt to compensate, non Hb A hemoglobins are increased (e.g., Hb A2, which is composed of a and globins, concentration increases). The presence of such hemoglobins in increased amounts aids in the diagnosis of b-thalassemia trait. Because all chains have a components, there is no excess of minor hemoglobins in a-thalassemia trait. In sickle cell states, mutated hemoglobins are present, rather than increased quantities of normal minor hemoglobins. In G6PD deficiency and unstable HB disease, HB becomes oxidized and precipitates as Heinz bodies.
Sickle cell trait
b- Thalassemia trait
G6PD deficiency
Unstable hemoglobin disease