In which condition is Hgb A2 typically elevated?

Hgb A2 is typically elevated in β-Thalassemia minor due to the underlying genetic defect affecting hemoglobin production. In this condition, the production of beta chains is decreased, leading to an imbalance in the hemoglobin composition. As a compensatory mechanism, the production of delta chains—resulting in Hgb A2—increases to maintain effective oxygen delivery and red blood cell integrity.

In β-Thalassemia minor, Hgb A2 levels can rise above the normal range (usually around 2.5% to 3.5%) and serve as a key diagnostic marker for this condition. The elevation of Hgb A2 is significant in distinguishing β-Thalassemia minor from other types of anemia, where Hgb A2 levels remain normal.

Recognizing this indicator is crucial for accurate diagnosis and helps in identifying individuals who may be carriers of the β-Thalassemia trait, allowing for appropriate genetic counseling and management.