Abstract
A new β−hemoglobin (Hb) variant, Hb Stockholm [β7(A4)Glu→Asp], is described. The variant was characterized by mass spectrometry and DNA sequencing. The new variant is clinically silent but interferes with Hb A1c quantification using ion exchange chromatography, causing a falsely low Hb A1c level when using the Bio-Rad VARIANT II™ System.