Hemoglobin electrophoresis pattern in beta-thalassemia trait is best described by which pattern?

Hemoglobin electrophoresis pattern in beta-thalassemia trait is best described by which pattern?

• A. High HbA, Low HbA2, Low HbF
• B. Normal HbA, Normal HbA2
• C. No HbA, High HbA2
• D. Low HbA, High HbA2, High HbF

Answer: (D)

In beta-thalassemia trait, there is reduced production of beta-globin chains, so HbA (the normal adult hemoglobin, alpha2beta2) falls. The body compensates by increasing the production of other hemoglobins containing alpha chains paired with delta or gamma chains, namely HbA2 (alpha2delta2) and HbF (alpha2gamma2). This leads to an electrophoresis pattern of low HbA with elevated HbA2 and elevated HbF. The HbA2 increase is a hallmark of beta-thalassemia trait, while HbF is often modestly increased as well. So the best description is a pattern with decreased HbA and increased HbA2 and HbF. The normal pattern would have normal HbA and HbA2; absence of HbA points toward major disease; a pattern with high HbA and low HbA2 wouldn’t fit the compensatory shift seen in beta-thalassemia trait.

In beta-thalassemia trait, there is reduced production of beta-globin chains, so HbA (the normal adult hemoglobin, alpha2beta2) falls. The body compensates by increasing the production of other hemoglobins containing alpha chains paired with delta or gamma chains, namely HbA2 (alpha2delta2) and HbF (alpha2gamma2). This leads to an electrophoresis pattern of low HbA with elevated HbA2 and elevated HbF. The HbA2 increase is a hallmark of beta-thalassemia trait, while HbF is often modestly increased as well.

So the best description is a pattern with decreased HbA and increased HbA2 and HbF. The normal pattern would have normal HbA and HbA2; absence of HbA points toward major disease; a pattern with high HbA and low HbA2 wouldn’t fit the compensatory shift seen in beta-thalassemia trait.