We report a clinically silent hemoglobin (Hb) variant, Hb Broomhill [α1 or α2 114(GH2) Pro > Ala;HBA1 or HBA2:c.343C > G] in a diabetic Chinese man. The Hb fractions of the subject were analyzed using various chromatographic and electrophoretic techniques. The glycated hemoglobin (HbA1c) levels measured using cation-exchange high-performance liquid chromatography (CE-HPLC) and the boronate affinity method showed nearly identical results. Analysis of the chromatogram of the CE-HPLC revealed an abnormal shoulder peak that appeared towards the end of the elution profile. Though the capillary electrophoresis method did not interpret the results, a manual examination revealed an abnormal shoulder on the HbA0 peak. Similarly, the electropherogram of the capillary zone electrophoresis also had an abnormal shoulder on the HbA peak. A missense mutation specific to the Hb Broomhill variant was found using Sanger sequencing.
Keywords: Hb Broomhill; HbA1c; capillary electrophoresis; cation-exchange high-performance liquid chromatography; hemoglobin variant.