Heterozygous mutation site was found in exon 2 of the FGA gene, c.104G > A(p.Arg35His).<h4>Conclusion</h4>When the fibrinogen (Clauss method) is significantly reduced and the thrombin time is prolonged, PT-derived method and the investigation of family coagulation function should be added, which can be used to diagnose and distinguish congenital dysfibrinogenemia from hypofibrinogenemia. Here, FGA is linked to Hypofibrinogenemia.