A rare hemoglobin variant (Hb Iraq-Halabja) causing spuriously low hemoglobin A1c values

Abstract

Various laboratory and patient-related factors can affect the measurement of hemoglobin A1c (HbA1c). We herein present the case of a diabetic patient with spuriously low HbA1c values on ion-exchange high-performance liquid chromatography (HPLC). Further investigations revealed that the patient was heterozygous for a rare Hb variant, namely Hb Iraq-Halabja (β10 Ala→Val). This is the second report of this variant published in the literature. Clinicians should be aware of the limitations of HbA1c assays because inaccurate values may lead to the inappropriate management of diabetes. Unusual or discrepant HbA1c test results should prompt further investigations for potentially interfering factors, including rare Hb variants. © 2013 by The Japanese Society of Internal Medicine.