Fibrinogen gamma-chain mutation, p.Ile171His, leads to hereditary hypofibrinogenemia

Abstract

Objective: To explore the clinical phenotype and genotype of a family with hereditary hypofibrinogenemia. Methods: Activated partial thrombin time (APTT), prothrombin time (PT),thrombin time (TT) and thrombelastogram (TEG) were tested in all family members. Fibrinogen activity and antigen were detected by Clauss method and immunoturbidimetric method respectively. All exons and flanking sequences of fibrinogen FGA,FGB,FGG genes were analyzed by PCR, and the products were subjected to Sanger sequencing. Results: The proband represented prolonged PT and TT, low Fg activity and antigen, elevated K value and decreased Angle value in TEG. Other family members reported similar changes including proband's father,daughter and son, and his elder brother and his niece. Exon 5 c.510_512 of FGG gene in the proband revealed a minor deletion mutation. Conclusion: The novel heterozygous missense mutation of exon 5 c.510_512del (Gln170_Ile171 del ins His) of FGG gene is the molecular mechanism that leads to hereditary hypofibrinogenemia in this family.