Protein C Deficiency Differential Diagnoses

Updated: May 24, 2021
  • Author: Shamudheen Rafiyath, MD; Chief Editor: Perumal Thiagarajan, MD  more...
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Diagnostic Considerations

Patients who develop venous thromboembolism (VTE) in the absence of acquired risk factors may have protein C deficiency or some other congenital thrombophilia, or may have protein C deficiency together with one or more other congenital risk factors for VTE. In a retrospective analysis of prospectively gathered data on 58 outpatients with VTE (approximate mean age 39 years) without major acquired risk factors, 45 had at least one hereditary risk factor for VTE. Diagnoses in these patients were as follows [63] :

  • Protein C deficiency - 18 patients
  • Protein S deficiency - 17 patients
  • Factor V Leiden mutation - 30 patients (25 heterozygous and five 5 homozygous)
  • Prothrombin gene mutation - 16 patients
  • Methylenetetrahydrofolate reductase C677T mutation - 24 patients (19 heterozygous, 5 homozygous)
  • Antithrombin III deficiency - 14 patients
  • Hyperhomocysteinemia - 13 patients

Of the 18 patients with protein C deficiency, four also had protein S deficiency, two also had hyperhomocystinemia, and one had both protein S deficiency and hyperhomocysteinemia.

These authors concluded that thrombophilia testing should be performed in younger VTE patients without known acquired risk factors. Testing for protein C, protein S, and prothrombin gene mutations should be followed by additional molecular assessment in patients with suspicious findings. [63]

Skin necrosis (eg, warfarin-induced skin necrosis) can occur not only in patients with protein C deficiency, but as a result of any of the following: 

Differential Diagnoses