False hemoglobin A1c value as a result of compound heterozygotes of hemoglobin E and hemoglobin New York

Abstract

Abstract The presence of hemoglobin (Hb) variants might interfere with some glycated hemoglobin (HbA1c) measurements. There have been a few reports of compound Hb variants affecting HbA1c testing. Here, we report a case of the coinheritance of two Hb variants in the β‐globin gene. High‐performance liquid chromatography with the Hb program showed a high HbA2 level. Similarly, an E‐window peak was separated on the high‐performance liquid chromatography with a glycated Hb program. However, capillary electrophoresis showed two abnormal peaks and no HbA peak. Sanger sequencing confirmed the presence of Hb New York and HbE. This is the first report of a compound heterozygote for HbE and Hb New York. The double heterozygote caused erroneous results for HbA1c on high‐performance liquid chromatography and enzyme assay.

Keywords

• HbA1c
• HbE
• Hb New York