First observation of hemoglobin G-Norfolk in the Turkish population


Ünal H., Atay A., Yücel M., Narin F., CEYLANER S. , Canatan D.

Turkish Journal of Biochemistry, vol.46, no.1, pp.95-100, 2020 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 46 Issue: 1
  • Publication Date: 2020
  • Doi Number: 10.1515/tjb-2019-0476
  • Title of Journal : Turkish Journal of Biochemistry
  • Page Numbers: pp.95-100
  • Keywords: abnormal hemoglobins, alpha chain variants, Hb G-Norfolk, HPLC, oxygen affinity, ALPHA-85 F6

Abstract

© 2020 De Gruyter. All rights reserved.Objectives: Hemoglobinopathies are inherited transition blood diseases associated with globin chains of the hemoglobin. However many mutations have been defined, there may bemany of themnot defined yet.Wehere report the first case of those mutations, named Hb G-Norfolk in Turkey. Case presentation: A 15 years-old male patient with erythrocytosis was referred to our laboratory for the evaluation of hemoglobinopathy. In chromatographic analysis, an unidentified peak was observed. A similar identification for variant Hb could not be obtained from High-Performance Liquid Chromatography (HPLC) analyzer's data library. No definitive diagnosis could also be made by different analyzer. Family screening and molecular genetic DNA sequence analysis were carried out. Conclusions: Although there were not found any beta gene mutation of neither the patient nor his family, analyses of alpha genes A1 and A2 were performed and abnormal hemoglobines were detected for all of them. This change in the HbA2 gene was at codon85 GAC>AAC (Asp>Asn) in the heterozygous state, known asHb G-Norfolk [HbA2:c256G>A p.Asp85Asn] based on HbVar database. Abnormal Hb bands detected by HPLCwith clinical findings such as erythrocytosis or cyanosis should be investigated by sequence analysis to corroborate alpha and/or beta-globin gene mutations for avoiding misdiagnosis and misinterpretation.