A Thrombotic State Due to an Abnormal Protein C

Abstract

PROTEIN C is the zymogen of a serine protease that regulates blood coagulation by inactivating thrombin-activated blood coagulation factors V and VIII.^{1 2 3} A congenital deficiency of this plasma protein is associated with a high incidence of thromboembolic disease.^{4 5 6} We report the case of a woman with thrombophilia who was heterozygous for both a deficiency and an abnormality of protein C, conditions inherited from her father and mother, respectively. Southern blot analysis of leukocyte DNA showed that the protein C gene was missing in an allele derived from the patient's father. DNA-sequence analysis of the protein C gene in the mutant . . .