Contents

Search

protein C deficiency

Classification: 1) type 1 a) most common form b) reduced immunological & biologic function; low functional & antigenic levels c) gene deletion, gene insertions 2) type 2 a) normal protein C antigen levels, but decreased activity b) point mutations 3) homozygous* patients die in utero or in infancy Etiology: 1) congenital deficiency a) type 1: low functional & antigenic levels b) type 2: low functional & normal antigenic levels 2) acquired deficiency a) disseminated intravascular coagulation (DIC) b) extensive DVT c) malignancy d) adult respiratory distress syndrome e) sepsis/infection f) post-operative patients g) hepatic disorders Epidemiology: - 2-3% of patients with venous thrombosis Pathology: - impaired regulation of blood coagulation - tendency to recurrent venous thrombosis Genetics: - autosomal dominant (heterozygous protein C deficiency) [3] - often develop thromoembolic disease before age 30 - however, many are asymptomatic - autosomal recessive homoygous protein C deficiency) [4] Clinical manifestations: 2) usually presents in late teens 3) most common presentation is DVT followed by PE 4) recurrent superficial thrombophlebitis 5) neonatal purpura fulminans &/or widespread organ thrombosis shortly after birth in homozygous* patients - homozygous form may vary from severe neonatal disease to late-onset thrombophilia Laboratory: - protein C level (functional assay) [5] - heterozygotes* have 30-60% of normal protein C - serum protein C antigen low Management: 1) heparin 2) low molecular weight heparin 3) warfarin (initial therapy with heparin) with INR of 2-3 - warfarin may cause skin necrosis & thrombosis in patients with protein C deficiency

Related

activated protein C (APC) resistance protein C in plasma (protein C assay) protein C; vitamin K-dependent protein C; anticoagulant protein C; autoprothrombin IIA; blood coagulation factor XIV; contains: vitamin K-dependent protein C light chain; vitamin K-dependent protein C heavy chain; activation peptide (PROC)

General

blood protein disorder enzyme deficiency hypercoagulability genetic disease of the blood/bone marrow

Database Correlations

OMIM correlations

References

  1. Contributions from Linda Kuribayashi MD, Dept of Medicine, UCSF Fresno
  2. Medical Knowledge Self Assessment Program (MKSAP) 11, 16. 18. American College of Physicians, Philadelphia 1998, 2012, 2018
  3. OMIM :accession 176860
  4. OMIM :accession 612304
  5. Khor B, Van Cott EM. Laboratory tests for protein C deficiency. Am J Hematol. 2010 Jun;85(6):440-2. PMID: 20309856