Objective: To analyze the phenotype and genotype of a family with congenital dysfibrinogenemia.
Methods: Assays of coagulation, including activated partial thromboplastin time(APTT), pro-thrombin time(PT)and thrombin time(TT) were carried out with Sysmex CA-7000 in the proband and his family members. The quality and quantity of fibrinogen in plasma were determined by Clauss and electrophoresis, respectively. Fibrinogen and inconstituent were analyzed by Native-PAGE. All exon and exon intron boundaries of fibringen genes were analyzed by direct sequencing.
Results: The proband had normal APTT, but prolonged PT and TT. The activity of fibrinogen in plasma was decreased while its quantity was normal. These abnormalities were also found in his sisters and daughter, while his wife was normal. Genetic analysis revealed heterozygous G1233A in the exon 2 of FGA which resulted in Arg16His missense mutation.
Conclusion: Inherited dysfibrinogenemia is caused by Arg16His mutation in exon 2 of FGA.