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Protein C deficiency


* Not a rare disease
Other Names for this Disease
  • Hereditary thrombophilia due to protein C deficiency
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Protein C deficiency is a disorder of blood clotting. People with this condition have an increased risk of developing abnormal blood clots. Protein C is found in the bloodstream and blocks the activity of (inactivates) certain proteins that promote blood clotting. Those with protein C deficiency do not have enough functional protein C to inactivate clotting proteins, which results in an increased risk of developing abnormal blood clots. Other factors can raise the risk of abnormal blood clots in people with mild protein C deficiency. These factors include increasing age, surgery, immobility, or pregnancy. The combination of protein C deficiency and other inherited disorders of blood clotting can also influence the risk. However, most people with mild protein C deficiency never develop abnormal blood clots. Protein C deficiency can be inherited or acquired. Inherited forms are caused by mutations in the PROC gene and inherited in an autosomal dominant fashion.[1]
Last updated: 9/20/2011


  1. Protein C deficiency. Genetics Home Reference. October 2009; Accessed 9/20/2011.
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Basic Information

  • Genetics Home Reference (GHR) contains information on Protein C deficiency. This website is maintained by the National Library of Medicine.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
  • LabTests Online provides information on testing protein C levels in general. Click on LabTests Online to view the information page.

In Depth Information

  • Medscape Reference provides information on this topic. Click on the link to view this information. You may need to register to view the medical textbook, but registration is free.
  • The Online Mendelian Inheritance in Man (OMIM) is an catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs.  Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Protein C deficiency. Click on the link to view a sample search on this topic.