Co-inherited β-thalassemia trait and HbH disease: clinical characteristics and interference in diagnosis of thalassemia by high-performance liquid chromatography

Introduction: To identify the clinical and hematological characteristics in a large group of patients with combined HbH disease and β-thalassemia trait.

Methods: Hemoglobinopathy analysis and full genotyping identified a cohort of patients with HbH disease, β-thalassemia trait, or combined HbH disease and β-thalassemia trait.

Results: Co-inheritance of β-thalassemia trait and HbH disease significantly decreased the mean corpuscular volume (MCV) in 27 patients when compared to 287 patients with HbH disease alone. The combined condition also alleviated anemia in nondeletional HbH disease but not in the deletional cases. Beta-thalassemia trait also significantly decreased the expression of HbH, Hb Constant Spring when present, and HbA(2) , with levels as low as 3.6% on high-performance liquid chromatography (HPLC).

Conclusion: These cases, although relatively common in the South Chinese population, may be difficult do diagnose correctly when only examined on HPLC. Therefore, molecular analysis of the α and β globin genes should be done in all cases with hemolytic anemia and low MCV without clear HbH disease or β-thalassemia parameters.