Reduced protein C activity

What it means

An abnormality of coagulation related to a decreased concentration of vitamin K-dependent protein C. Protein C is activated to protein Ca by thrombin bound to thrombomodulin. Activated protein C degrades factors VIIIa and Va.

Protein C can function as an anticoagulant by irreversibly proteolytically inactivating Factor Va and Factor VIIIa. Therefore, a defect in protein C is associated with an increased risk of thrombosis.

Rare diseases that can present with this10

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Protein C deficiency