Hypofibrinogenemia caused by a heterozygous variant in the FGA gene: a case report.

Abstract

Background: Hereditary Fibrinogen Disorders (HFDs) are conventionally classified as quantitative (type I) or qualitative (type II) deficiencies based on the plasma concentration. Quantitative deficiencies include afibrinogenemia/severe hypofibrinogenemia and hypofibrinogenemia, while qualitative deficiencies comprise dysfibrinogenemia and hypodysfibrinogenemia.

Objective: To identify the molecular pathogenesis of hypofibrinogenemia in a pregnant patient and her family, and explore the clinical characteristics and peripartum management strategy of this disease.

Methods: We described the clinical data and genetic findings of a 28-year-old pregnant woman and her mother with hypofibrinogenemia. Sanger sequencing was used to verify the heterozygous variant c.1517del (exon 5) of the FGA gene (NM_021871.4). Relevant published literatures were analyzed to summarize the research progress and clinical implications of this variant.

Results: We identified a novel pathogenic FGA c.1517del variant in a Chinese family with hereditary hypofibrinogenemia. The proband presented with decreased fibrinogen activity (1.6 g/L) and antigen level (1.7 g/L), with an activity/antigen ratio of 0.94; her mother showed similar laboratory abnormalities. The patient received 1.5 g intravenous fibrinogen before neuraxial anesthesia-assisted lower-segment cesarean section. A 3.53 kg female neonate was delivered smoothly without obvious intraoperative hemorrhage.

Conclusion: The diagnosis of HFDs relies on combined detection of fibrinogen function, antigen level and genetic analysis. Genetic screening facilitates clinical diagnosis and genetic counseling. For pregnant patients with hypofibrinogenemia in late gestation, preoperative fibrinogen supplementation can effectively correct coagulation defects and ensure safe delivery.