Journal of Diabetes and Its Complications
Volume 25, Issue 1 , Pages 14-18 , January 2011

Hemoglobin Raleigh results in factitiously low hemoglobin A1c when evaluated via immunoassay analyzer

  • Nina Jain

      Affiliations

    • Division of Pediatric Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
    • Corresponding Author InformationCorresponding author. Division of Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, CB#7039, 3341 MBRB, Chapel Hill, NC 27599-7039, USA. Tel.: +1 919 966 4435x244; fax: +1 919 966 2423.
    • ,
  • Mehmet Kesimer

      Affiliations

    • Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
    • ,
  • James D. Hoyer

      Affiliations

    • Laboratory of Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
    • ,
  • Ali S. Calikoglu

      Affiliations

    • Division of Pediatric Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA

Received 3 June 2009 ,Revised 31 August 2009 ,Accepted 25 September 2009.

  • Image Result

    (A) Hb gel electrophoresis: denatured Hb protein analyzed by gel electrophoresis. Top lane representing ladder. Middle lane, control sample of hemoglobin. Bottom lane, patient sample, reveals the pres

    (A) Hb gel electrophoresis: denatured Hb protein analyzed by gel electrophoresis. Top lane representing ladder. Middle lane, control sample of hemoglobin. Bottom lane, patient sample, reveals the presence of a β-chain hemoglobin variant. (B) Hb HPLC analysis . HPLC revealed the presence of Hb Raleigh in the patient sample. (C) Hb ESI mass spectra analysis. ESI mass spectra of intact Hb reveals two β-chain peaks separated by 14.0 Da indicating the presence of a variant β-chain as heterozygote. (D) MS/MS spectra of N-terminal tryptic peptide of the variant Hb β-chain. Two different precursor ions were observed from the N-terminus: One 951.49 Da with sequence of VHLTPEEK (normal, not shown) and the other 965.45 Da with sequence of A*HLTPEEK (variant). The 14-Da mass difference was equal to Val→Ala substitution (−28 Da) and acetylation of alanine (+42). (E) DNA sequencing of exon 1 of the beta globin gene in the forward direction. There is a GTG to GCG substitution at codon 1 (arrow), consistent with Hb Raleigh.

PII: S1056-8727(09)00095-6

doi: 10.1016/j.jdiacomp.2009.09.004

Journal of Diabetes and Its Complications
Volume 25, Issue 1 , Pages 14-18 , January 2011

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