Non-Malaysian citizens are subject to 6% SST, to be verified and paid at the counter before screening.
Protein S is a vitamin K–dependent glycoprotein synthesized in the liver and a key component of the natural anticoagulant system. Protein S serves as a cofactor for Protein C, helping Activated Protein C (APC) degrade clotting factors Va and VIIIa, thereby preventing excessive clotting and maintaining blood flow balance.
Deficiency in Protein S reduces anticoagulant capacity and increases the risk of deep vein thrombosis (DVT) and pulmonary embolism.
A venous blood sample is tested for Protein S activity or antigen level. Results should be interpreted alongside Protein C, coagulation factors, and clinical context.
Q1: What’s the difference between Protein S and Protein C deficiency?
A: Both are anticoagulant proteins. Protein S acts as a cofactor for Protein C, and deficiency in either raises thrombosis risk.
Q2: Does Protein S deficiency always cause thrombosis?
A: Not always, but it significantly increases the likelihood of venous thrombosis.
Q3: What conditions can temporarily lower Protein S levels?
A: Pregnancy, oral contraceptive use, acute thrombosis, liver disease, and vitamin K deficiency can all lower Protein S.