title: Protein C and protein S deficiencies.
abstract: The protein C (PC) pathway, with its cofactor protein S (PS), is an important natural antithrombotic mechanism. Both PC and PS deficiencies have been implicated in thrombophilia. The molecular basis for hereditary PC and PS deficiencies is highly heterogeneous, with a large spectrum of mutations that have various effects on the expression of the relevant allele. A small subset of patients who are homozygous or compound heterozygous for a PC gene mutation have severe thrombotic complications at birth, whereas onset occurs later in the other cases. Patients heterozygous for a PC or PS gene abnormality may develop recurrent thrombosis during adulthood, with a probability of remaining free of thrombosis of about 50% at age 45. A PC or PS gene defect is associated with the factor V Arg 506 to Gln mutation in 10% to 30% of symptomatic patients, suggesting that clinical expression is controlled by several genes in heterozygous patients.
authors.affiliation: Unité INSERM 428, UFR des Sciences Pharmaceutiques et Biologiques, Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Aiach
authors.forename: D
authors.initials: D
authors.lastname: Borgel
authors.forename: P
authors.initials: P
authors.lastname: Gaussem
authors.forename: J
authors.initials: J
authors.lastname: Emmerich
authors.forename: M
authors.initials: M
authors.lastname: Alhenc-Gelas
authors.forename: S
authors.initials: S
authors.lastname: Gandrille
mesh_terms: D002874:Chromosome Mapping; D005796:Genes / Q000235:genetics / Q000502:physiology; D006801:Humans; D017354:Point Mutation / Q000235:genetics / Q000502:physiology; D011486:Protein C / Q000235:genetics* / Q000378:metabolism; D020151:Protein C Deficiency; D018455:Protein S Deficiency / Q000235:genetics* / Q000378:metabolism; D013927:Thrombosis / Q000235:genetics / Q000503:physiopathology
chemical_list: D011486:Protein C