Compound heterozygous protein C deficiency with pulmonary embolism caused by a novel PROC gene mutation: Case report and literature review

Protein C is an anticoagulation agent, and protein C deficiency results in vascular thrombosis disease. Hereditary protein C deficiency is a risk factor for pulmonary embolism in adults. Pathogenic variants of the Protein C, Inactivator Of Coagulation Factors Va And VIIIa (PROC) gene which encodes protein C have been identified as a cause of protein C deficiency. PATIENT CONCERNS: We describe a patient with a novel mutation in the PROC gene who was diagnosed with pulmonary embolism in a Chinese family. DIAGNOSIS: According to the results of the pulmonary computed tomography angiography (CTA) and the level of blood protein C, the patient was diagnosed with pulmonary embolism caused by protein C deficiency. INTERVENTIONS: Whole-exome sequencing (WES) was performed for the molecular analysis. OUTCOME: The results of patient’s deoxyribonucleic acid revealed a heterozygous mutation (c.237 + 5G > A) in intron 3 of the PROC gene. His father also harbored the same mutation in the PROC gene. We also reviewed the protein C deficiencies caused by PROC gene mutations in cases. LESSONS: A novel mutation in intron 3 of PROC gene has not been previously reported in patients with pulmonary embolism caused by protein C deficiency. After anticoagulation therapy, the patient recovered, and CT showed resolution of the thrombosis. Pulmonary embolism may be caused by protein C deficiency and the rare compound heterozygous mutation in intron 3 of the PROC gene could cause protein C deficiency via impairment of the secretory activity of protein C.