Adult-onset arterial thrombosis in a pedigree of homozygous and heterozygous protein C deficiency

摘要

Protein C is a vitamin K-dependent serine protease with a central role in the regulation of blood coagulation. Protein C deficiency is an autosomally inherited disorder associated with an increased risk of thrombosis [1]. Most patients with clinical expression of thrombosis are heterozygous for protein C deficiency, and exhibit decreased protein C activity [1]. A much rarer homozygous or compound heterozygous form of protein C deficiency generally manifests as neonatal purpura fulminans [1 ]. Infants with homozygous protein C deficiency, however, usually have several asymptomatic heterozygous relatives [2-4]. Thus, it has been postulated that unknown factors induce a variety of thrombotic manifestations in protein C deficiency carriers [5-7]. The genotype-phenotype relationship of thrombosis in protein C deficiency remains to be elucidated [2-4]. In the present study, we report a case of a 44-year-old man with a missense homozygous mutation (Pro369Leu) who developed a mesenteric artery thrombosis as the first thrombotic event at the age of 34 years.