Analysis of Iranian patients allowed the identification of the first truncating mutation in the fibrinogen Bβ-chain gene causing afibrinogenemia

Rosanna Asselta, Silvia Spena, Stefano Duga, Flora Peyvandi, Massimo Malcovati, Pier Mannuccio Mannucci, Maria Luisa Tenchini

Research output: Contribution to journalArticle

Abstract

Background and Objectives. Congenital afibrinogenemia is a rare coagulation disorder whose molecular basis is still poorly characterized. Most mutations have been identified in the fibrinogen Aα- and γ-chain genes, whereas only two missense mutations have been reported in the Bβ-chain gene. The aim of this work was to widen knowledge about the mutational spectrum of this disease by analyzing the molecular bases of congenital afibrinogenemia in three unrelated Iranian patients. Design and Methods. All patients showed unmeasurable levels of clottable fibrinogen in plasma. Mutational screening was performed by sequencing the whole coding region, including exon-intron boundaries and part of the promoter region of the three fibrinogen genes. Results. Sequencing in one patient revealed the presence of a novel nonsense mutation (3282C→T) in exon 2 of the fibrinogen Bβ-chain gene, causing a severe truncation of the corresponding polypeptide (R17X). In the remaining probands, two already known small deletions (4209delA and 4220delT), both located in exon 5 of the fibrinogen Aα-chain gene, were identified, and their effect at the protein level explored by computer-assisted analysis. Interpretation and Conclusions. The identification of the first truncating mutation in the fibrinogen Bβ-chain gene confirms the involvement of all three fibrinogen genes in the pathogenesis of congenital afibrinogenemia and widens the mutational spectrum of the disease. This knowledge is clinically essential in order to carry out prenatal diagnosis in families at risk.

Original languageEnglish
Pages (from-to)855-859
Number of pages5
JournalHaematologica
Volume87
Issue number8
Publication statusPublished - 2002

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Keywords

  • Afibrinogenemia
  • Bβ-chain gene
  • Fibrinogen
  • Gene analysis
  • Nonsense mutation

ASJC Scopus subject areas

  • Hematology

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