High Performance Liquid Chromatography was used for quantization of HbA2 because of the simplicity of sample preparation, superior resolution, and accuracy, combined with complete automation of the method.[22] Diagnosis of BTT was based on levels of HbA2 greater than 3.5 %.[23] Reduction of HbA2 because of coincident iron deficiency did not preclude detection of BTT.[24]. Here, HBA2 is linked to Iron deficiency anemia.