PROS1 Cys475Tyr mutation associated with a type III protein S deficiency pattern.
José A Mejias-Figueroa, Charlotte M Story, Michael B Streiff
✦ AI-curated · Sources linked
Case in brief
A 35-year-old woman with a history of deep vein thrombosis was diagnosed with protein S deficiency. After initial treatment with parenteral anticoagulation, she transitioned to a direct oral anticoagulant. Five years later, repeat testing revealed a type III deficiency pattern and a PROS1 mutation (Cys475Tyr), which is implicated in the protein's antithrombotic function.
What made this case unusual
The identification of the PROS1 Cys475Tyr mutation, which affects a cysteine residue involved in disulfide bonding, highlights a specific genetic alteration linked to type III protein S deficiency.
Diagnostic / clinical pearl
Clinicians should consider genetic testing for PROS1 mutations in patients with protein S deficiency, especially when atypical deficiency patterns are observed.
Why it matters
Understanding the genetic basis of protein S deficiency can aid in risk assessment and management of thrombotic events in affected individuals.