Objective   To improve the understanding and diagnosis and treatment of congenital dysfibrinogenemia (CD) through analyzing the clinical data of a pediatric patient and his pedigree.

  Methods  The clinical manifestations, laboratory findings and treatment of a case of CD diagnosed at West China Second University Hospital, Sichuan University and those of its pedigree members were analyzed, and genetic tracing and follow-up were conducted on the patient and its pedigree.

  Results  The child has no clinical manifestations at the time of admission. Coagulation function examination showed normal prothrombin time (PT), normal activated partial thrombin time (APTT), significantly prolonged thrombin time (TT), fibrinogen activity (Fg: C<0.5 g/L) measured with the Clauss method, and fibrinogen antigen (Fg: Ag) measured at 2.8 g/L with PT algorithm. Gene sequencing results showed that heterozygous missense mutation c.901C>T (p.Arg301Cys) in exon 8 of FGG gene. Combined with the family history, the child was diagnosed with CD. During the follow-up of 4⁺ months, the patient did not present bleeding, abnormal coagulation or thrombosis, and the coagulation function did not show significant changes compared with the findings obtained on admission.

  Conclusion  The diagnosis of CD is confirmed mainly based on genetic testing and the treatment is characterized by the principle of precise individualized treatment. No special treatment is needed for patients presenting no clinical manifestations. However, it is important to provide thorough prenatal diagnosis and follow-up services for female patients planning for pregnancy so as to prevent miscarriage and complications caused by postpartum coagulation dysfunction.