title: 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.
authors.affiliation: Department of Laboratory Medicine, Yuan's General Hospital, Taiwan.
authors.forename: Chi-Fen
authors.initials: CF
authors.lastname: Chen
authors.forename: Chih-Ming
authors.initials: CM
authors.lastname: Chien
authors.forename: Su-Ching
authors.initials: SC
authors.lastname: Liu
authors.forename: Yen-Kuang
authors.initials: YK
authors.lastname: Tai
mesh_terms: D019943:Amino Acid Substitution; D001483:Base Sequence; D001774:Blood Chemical Analysis; D004247:DNA / Q000235:genetics; D004252:DNA Mutational Analysis; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D006442:Glycated Hemoglobin / Q000032:analysis*; D006455:Hemoglobins, Abnormal / Q000032:analysis* / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D013624:Taiwan
chemical_list: D004247:DNA; D006442:Glycated Hemoglobin; D006455:Hemoglobins, Abnormal; C120162:hemoglobin Iraq-halabja