# Lessons from an elderly patient with pulmonary embolism caused by protein S deficiency: a case report

## TL;DR

An elderly woman with a dangerous blood clot was found to have a genetic mutation affecting protein S, highlighting the importance of genetic testing for personalized treatment and family education.

## Contribution

The case underscores the necessity of genetic testing in pulmonary embolism patients with thrombophilia indicators for accurate diagnosis and family counseling.

## Key findings

- A PROS1 gene mutation was identified as the cause of reduced protein S activity in a patient with DVT and PE.
- Personalized anticoagulation and a vena cava filter prevented further thrombotic events in a 1-year follow-up.
- Family members with the mutation received targeted education and interventions.

## Abstract

Lower limb deep vein thrombosis (DVT) concurrent with pulmonary embolism (PE) is perilous, particularly in the elderly, exhibiting heterogeneity with thrombophilia mutations. Tailored treatment is essential, yet sudden deaths complicate causative factor elucidation. This report emphasizes genetic testing necessity in PE patients with thrombophilia indicators, facilitating cause identification, personalized treatment guidance, and family education.

This study details a 75-year-old Chinese woman with DVT and PE, where genetic testing identified thrombophilia, guiding personalized treatment decisions.

Upon admission, the patient, after over 10 days of bed rest, presented chest tightness, shortness of breath, and unilateral leg swelling. Diagnostic measures revealed DVT and a substantial PE. Genetic testing identified a PROS1 gene C200A>C mutation, reducing protein S activity. Following 2 weeks of anticoagulation and inferior vena cava filter insertion, the patient, discharged, initiated lifelong anticoagulant therapy. A 1-year follow-up showed no recurrent thrombotic events. Family members carrying the mutation received informed and educational interventions.

Genetic testing for thrombophilic predisposition post-PE is crucial, elucidating etiology, guiding individualized treatment, and playing a pivotal role in family education.