[Fibrinogen beta chain gene mutation contributes to one congenital afibrinogenemia]

To identify the fibrinogen (Fg) gene mutations in a Chinese pedigree of congenital afibrinogenemia.

The plasma Fg activity and protein of the proband and his family members were detected. Genomic DNA was isolated from the peripheral blood mononuclear cells. All the exons and exon-intron boundaries of fibrinogen gene were amplified by PCR and sequenced thereafter.

Two mutations, 7972 del G in FGB and T2543A in FGG, were found in the proband.

FGG2543 is a polymorphism site, which lead to the polymorphism of gamma144 I/K. The G deletion at base 7972 of FGB contributes to the frameshift mutation after amino acid 419, resulting in the truncated beta chain without the terminal 27 amino acids. The latter may contributes to the pathogenetic mechanisms in Chinese congenital afibrinogenemia patients. The G deletion at base 7972 of FGB is identified for the first time.