Hb A_1c Determination by Capillary Electrophoresis is an Efficient Method for Detecting β-Thalassemias and Hemoglobin...

Glycated hemoglobin (Hb A_1c) determination by multicapillary zone electrophoresis (MZE) can additionally be used to detect Hb A₂, Hb F and most common hemoglobin (Hb) variants. We assessed the effectiveness of this method for detecting β-thalassemia (β-thal), δβ-thalassemia (δβ-thal) and most common Hb variants. Moreover, Hb F/Hb A₂ is evaluated as an index for discriminating between β- and δβ-thal traits. The theoretical β-thalassemia major (β-TM) birth rate in our healthcare area is calculated and contrasted with real data. A MZE technique was used for Hb A_1c measurements in 27,724 patients. Previous criteria for carrier detection were established and subsequently confirmed by molecular biology techniques. Positive predictive value (PPV) was 100.0%. The prevalence of β-thal trait (including δβ-thal) was 0.34%. The most prevalent mutations (estimated per 100,000 population) were HBB: c.118C > T (57.7%), HBB: c.93-21G>A (50.5%), HBB: c.92 + 1G > A (43.3%), HBB: c.92 + 6T > C (32.5%) and HBB: c.20delA (18.0%) for β-thalassemias, and Hb S (HBB: c.20A > T) (32.5%) and Hb J-Baltimore (HBB:c.3880T>A) (28.9%) for Hb variants. We found a paradoxical result between the theoretical β-TM birth rate and real data. We calculated an optimal Hb F/Hb A₂ index cutoff of 0.71 for discriminating between β- and δβ-thal traits. This method is highly cost-effective for detecting β-thalassemias and common Hb variants. Prevalence results match previous data for the Spanish population. Heterogeneity of mutations in Spain has markedly increased as a consequence of migration. The Hb F/Hb A₂ index cutoff could be used to predict δβ-thal trait.