Protein C and protein S deficiencies.
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.
Aiach
M
M
Unité INSERM 428, UFR des Sciences Pharmaceutiques et Biologiques, Paris, France.
Borgel
D
D
Gaussem
P
P
Emmerich
J
J
Alhenc-Gelas
M
M
Gandrille
S
S
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
D011486:Protein C