Phenotypic and genetic analysis of hypofibrinogenemia because of a novel missense mutation in the FGB: Leu121Arg.

: In this study, we found a novel missense gene mutation of fibrinogen (FIB) and it will help us to understand the pathogenesis of this type of disease. The FIB activity (FIB:C) and FIB antigen (FIB:Ag) were detected using matched commercially available kits. To identify the novel missense mutation, the fibrinogen gene sequencing was carried out. Bioinformatics and model analysis were used to study the harm of the mutation. The FIB:C and FIB:Ag of the proband were 0.82 and 1.19 g/l, respectively. Sequencing analysis detected a heterozygous c.425T>G in exon three of FGB gene resulting in p.Leu121Arg. The Leu121Arg mutation was responsible for the decrease of FIB:C, and it was the first report of such a mutation in the world.