Measurement of Hemoglobin Variants in Hemoglobinopathies
Keywords:Hemoglobinopathies, sickle cell, hemoglobin patterns, electrophoresis, complete blood count
Background: Hemoglobinopathies are a group of inherited disorders triggered by defects in globin genes which lead to abnormal hemoglobin (Hb) level and structure with reduced oxygen-carrying capacity. Qualitative and quantitative laboratory measurements are routinely used to diagnose and differentiate various types of hemoglobinopathies. However, these measurements vary across diseases and populations.
Aims: To report the measurement of Hb variants in a Saudi cohort of patients with hemoglobinopathies and hemoglobinopathy traits (sickle-cell and thalassemia traits).
Methods: This was a retrospective study on patients with hemoglobinopathies who attended King Abdulaziz Medical City (Jeddah city, Western Saudi Arabia) in 2019. The data comprised patient diagnosis, age, gender, complete blood count and Hb electrophoresis.
Results: The study included 184 patients (52% females, 48% males) of which 70% were aged >12 years, 28% aged >1-12 years and 2% aged <1 year. Maximum patients were diagnosed with sickle cell disease (61%) followed by hemoglobinopathy trait (19%). Hb concentration, red blood cell (RBC) count and packed cell volume (PCV) were significantly reduced in children and adolescent and above age group patients whereas in infants, no significant difference was found in RBC count and PCV. The mean HbA% was highest in alpha-thalassemia trait (97%) followed by beta-thalassemia minor (92.8%). Moreover, HbD disease was found in 82.8%, HbC disease in 67.6%, beta-thalassemia intermediate in 51.8%, sickle cell trait in 47.5% and HbE disease in only 12%. In addition, HbF and HbA2 were present in all detected hemoglobinopathies and traits at varying levels.
Conclusion: Hemoglobinopathies and hemoglobinopathy traits require comprehensive laboratory examination using CBC, blood cell morphology, qualitative and quantitative electrophoresis. The results indicate the importance of quantifying HbA, HbF and HbA2 to aid in the differential diagnosis of different types of hemoglobinopathies.