title: Unreliable estimation of HbA due to the presence of Camperdown haemoglobin [beta 104 (G6) Arg --> Ser].
abstract: OBJECTIVE
  To suggest the possible unreliability of HbA(1c) determination in presence of haemoglobin variants during routine metabolic evaluation.
  
  
  METHODS
  We present a case of Camperdown haemoglobin, accidentally detected in a middle-aged Italian man during routine metabolic evaluation for newly diagnosed diabetes. The haemoglobin variant has been identified by exchange high performance liquid chromatography (CE-HPLC) (VARIANT trade mark HbA(1c) Program, Bio-Rad Laboratories, Hercules, CA, USA), and characterized at molecular level by direct sequencing.
  
  
  RESULTS
  A 56-year-old male of Northern Italian origin, presented to our centre for a Type 2 diabetes mellitus of recent diagnosis. HbA(1c) determination was routinely determinated. The patient's chromatogram showed an inappropriate peak of 38.5% in the HbA(1c) position suggestive for the presence of abnormal haemoglobin. Further evaluation identified an abnormal haemoglobin peak even higher (49.5%) eluting at 1.34 minutes in P2-window. Molecular characterization of the mutation showed a nucleotide replacement, AGG --> AGC at codon 104, causing the amino acid replacement Arg --> Ser at position 104 (G6) that give rise to Hb Camperdown.
  
  
  CONCLUSIONS
  Haemoglobinopathies can lead to inaccurate glycated haemoglobin level determination. In patients carrying haemoglobin variants, the different methods for determinations of glycated haemoglobin could result in different errors, showing either higher or lower values than expected.
authors.affiliation: U. O. di Medicina d'Urgenza e Pronto Soccorso Ospedale Maggiore Policlinico IRCCS, Milan, Italy. Castelli39@interfree.it
authors.forename: R
authors.initials: R
authors.lastname: Castelli
authors.forename: A
authors.initials: A
authors.lastname: Tempesta
authors.forename: A
authors.initials: A
authors.lastname: Bianchi
authors.forename: T
authors.initials: T
authors.lastname: Porro
authors.forename: G
authors.initials: G
authors.lastname: Ivaldi
authors.forename: M D
authors.initials: MD
authors.lastname: Cappellini
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003920:Diabetes Mellitus / Q000097:blood* / Q000235:genetics; D006442:Glycated Hemoglobin / Q000032:analysis*; D006455:Hemoglobins, Abnormal / Q000032:analysis* / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D015203:Reproducibility of Results
chemical_list: D006442:Glycated Hemoglobin; D006455:Hemoglobins, Abnormal; C044399:hemoglobin Camperdown