Which statement about HbA2 in beta-thalassemia trait is true?

Which statement about HbA2 in beta-thalassemia trait is true?

• A. HbA2 Is Elevated
• B. HbA2 Is Decreased
• C. HbA2 Unchanged
• D. HbA2 Absent

Answer: (A)

In beta-thalassemia trait, reduced synthesis of beta-globin chains prompts the body to compensate by increasing delta-chain production, which raises the amount of HbA2 (alpha2 delta2) in the blood. HbA2 normally makes up about 2-3% of total hemoglobin, but it commonly rises above 3.5% in beta-thalassemia trait. This elevation helps distinguish the trait from iron deficiency anemia, where HbA2 is not typically elevated. So the true statement is that HbA2 is elevated. HbA2 is not decreased, unchanged, or absent in this condition because the delta-chain contribution increases in response to the beta-chain deficiency.

In beta-thalassemia trait, reduced synthesis of beta-globin chains prompts the body to compensate by increasing delta-chain production, which raises the amount of HbA2 (alpha2 delta2) in the blood. HbA2 normally makes up about 2-3% of total hemoglobin, but it commonly rises above 3.5% in beta-thalassemia trait. This elevation helps distinguish the trait from iron deficiency anemia, where HbA2 is not typically elevated. So the true statement is that HbA2 is elevated. HbA2 is not decreased, unchanged, or absent in this condition because the delta-chain contribution increases in response to the beta-chain deficiency.