A Case of Coagulation Dysfunction Caused by Antithrombin Pittsburgh Mutation.

Background: In clinical practice, coagulation dysfunction resulting from the antithrombin Pittsburgh mutation is rare and prone to misdiagnosis.

Methods: Coagulation time was measured using coagulation methods, and coagulation factor activity was measured using chromogenic substrate methods. Platelet aggregation function was assessed by light transmission aggregometry (LTA), serum protein was determined through capillary electrophoresis, and mutations were detected by whole-exome high-throughput sequencing.

Results: A 16-year-old female patient had significantly prolonged activated partial thromboplastin time (APTT) and thrombin time (TT). Moreover, the activity of coagulation factors VIII and IX was markedly decreased. Normal human plasma failed to correct the APTT, and the lupus anticoagulant screening test was normal. The coagulation factor VIII inhibitor was 0.10 BU/mL, while the factor IX inhibitor was 1.60 BU/mL. Protamine could not correct the TT. The mother had multiple postoperative bleedings and died due to massive postpartum hemorrhage. Through whole-exome sequencing for genetic testing of hereditary diseases, an antithrombin Pittsburgh mutation associated with the SERPINA1 gene was revealed.

Conclusions: Patients with the antithrombin Pittsburgh mutation show significant coagulation abnormalities, with their clinical bleeding manifestations varying considerably. Bleeding from trauma or surgery may be a prominent feature in these patients.