Overview
Hemoglobin H (HbH) disease is a form of α-thalassemia characterized by the presence of HbH and HbA, resulting from the inheritance of two α-globin gene deletions or mutations, typically leaving one functional α-globin gene per cell 2.Diagnosis
Hemoglobin Electrophoresis: Essential for identifying HbH and quantifying HbA, HbH, and other abnormal hemoglobins 2.
Molecular Analysis: Recommended for identifying specific α-thalassemia mutations such as -3.7α, -4.2α, and -SEA mutations 2.
Complete Blood Count (CBC): Often shows microcytic anemia with hypochromia 2.
Peripheral Blood Smear: May reveal target cells and nucleated red blood cells 2.Management
Supportive Care: Regular monitoring of hemoglobin levels and management of anemia with iron supplementation if iron deficiency coexists 2.
Blood Transfusions: Indicated for severe anemia or acute hemolytic crises 2.
Hydroxyurea: Not typically recommended for HbH disease but may be considered in specific cases of ineffective erythropoiesis 2.Special Populations
Pregnancy: Requires close monitoring of maternal and fetal well-being; may necessitate transfusions for severe anemia 2.
Pediatrics: Early diagnosis and management crucial to prevent developmental delays due to chronic anemia 2.
Elderly: Similar management principles apply, with emphasis on managing complications like cardiovascular strain from chronic anemia 2.Key Recommendations
Perform hemoglobin electrophoresis and molecular analysis for α-thalassemia mutations in patients with unexplained microcytic anemia 2 (Evidence: Strong).
Implement regular monitoring and supportive care including iron supplementation if indicated 2 (Evidence: Moderate).
Consider blood transfusions for managing severe anemia or acute hemolytic episodes 2 (Evidence: Moderate).References
1 Belton J, Hoens A, Scott A, Ardern CL. Patients as Partners in Research: It's the Right Thing to Do. The Journal of orthopaedic and sports physical therapy 2019. link
2 Dastidar R, Gajra B, De M. Molecular and hematological characterization of hemoglobin H disease in the Bengali population of Kolkata, India. Genetic testing and molecular biomarkers 2011. link