Congenital dysfibrinogenemia (CD) is a rare hereditary
fibrinogen disorder characterized by normal
fibrinogen antigen levels associated with lower functional activities. The aim of this study is to analyze the phenotype and genotype of a family of CD. Routine coagulation screening tests were performed on the proband, her parents, and her grandparents. Then, the purified genomic
DNA extracted from peripheral blood was amplified by PCR, and Sanger sequencing was performed to further confirm the mutation. The prothrombin time and activated partial thromboplastin time of the proband were normal, thrombin time prolonged, and the activity of
fibrinogen (Fg:Ac) decreased significantly, but
fibrinogen antigen (Fg:Ag) level was normal. The coagulation function indices of the proband's father and grandfather were similar to her, and the indices of her mother and grandmother were normal. Sequencing results showed that the proband had a heterozygous missense mutation in FGA gene c.92G > A, which caused the mutation of
amino acid 31 from
glycine to
glutamic acid (p.Gly31Glu). Her father had the same heterozygous mutation. In conclusion, the proband suffered from CD. The change of Gly31Glu in A chain due to the c.92G > A heterozygous missense mutation in the FGA gene is the cause of CD in the family. To the best of our knowledge, the mutation site is new and first reported so far.