Hereditary Coagulopathy Antithrombin III Deficiency Complicated with Pulmonary Embolism: A Case Report

Hereditary coagulopathy complicated with pulmonary embolism is uncommon clinically. The disease should be considered in young adults with coagulopathy and progressive unexplained dyspnea. We report a 20-year-old young man who was admitted due to episodes of exercise intolerance, hemoptysis and progressive dyspnea. The chest X-ray and bronchoscopy were normal, and the laboratory survey showed D-dimer ＞2000ng/dl. The perfusion scan revealed an extensive left lower lobe perfusion defect but the ventilation scan was normal. Pulmonary angiography disclosed a left lower pulmonary artery filling defect, which confirmed the diagnosis of a pulmonary embolism. Antithrombin III, protein C and protein S were checked in this patient due to his having a pulmonary embolism at such a young age. The antithrombin III level was 48.8% (normal range: 75-125%). We screen the antithrombin III level of his family, since antithrombin III deficiency has a highly-inheritable tendency. We found that his grandfather, father, uncle, aunt and younger sister all had an antithrombin III deficiency.