title: Identification of a rare variant haemoglobin (Hb Sinai-Baltimore) causing spuriously low haemoglobin A(1c) values on ion exchange chromatography.
abstract: Commonly used methods for assay of haemoglobin A(1c) (HbA(1c)) are susceptible to interference from the presence of haemoglobin variants. In many systems, the common variants can be identified but scientists and pathologists must remain vigilant for more subtle variants that may result in spuriously high or low HbA(1c) values. It is clearly important to recognize these events whether HbA(1c) is being used as a monitoring tool or, as is increasingly the case, for diagnostic purposes. We report a patient with a rare haemoglobin variant (Hb Sinai-Baltimore) that resulted in spuriously low values of HbA(1c) when assayed using ion exchange chromatography, and the steps taken to elucidate the nature of the variant.
authors.affiliation: Clinical Biochemistry Department, Southern Community Laboratories, 3rd Floor, Clinical Services Building, Dunedin Hospital, 201 Great King Street, Dunedin 9016, New Zealand. geoff.smith@sclabs.co.nz
authors.forename: Geoff
authors.initials: G
authors.lastname: Smith
authors.forename: Heather
authors.initials: H
authors.lastname: Murray
authors.forename: Stephen O
authors.initials: SO
authors.lastname: Brennan
mesh_terms: D000369:Aged, 80 and over; D019943:Amino Acid Substitution; D016477:Artifacts; D002852:Chromatography, Ion Exchange; D006442:Glycated Hemoglobin / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D006453:Hemoglobinopathies / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D006455:Hemoglobins, Abnormal / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D017422:Sequence Analysis, DNA
chemical_list: D006442:Glycated Hemoglobin; D006455:Hemoglobins, Abnormal; C517652:hemoglobin A1c protein, human; C086552:hemoglobin Sinai-Baltimore