Mesenteric venous thrombosis in hereditary protein C deficiency with the mutation at Arg169 (CGG-TGG).

A 39-year-old man with no significant medical history was admitted to our hospital with severe abdominal pain and melena. Computed tomographic (CT) scans demonstrated superior mesenteric venous thrombosis. Although thrombolysis and anticoagulant therapy was started immediately, symptoms of strangulation ileus developed. Laparotomy was therefore performed and revealed necrotic stenosis of the ileum. The patient, his father and sisters showed low protein C levels. Direct sequencing analysis of their protein C gene revealed a heterozygous mutation at codon 169 corresponding to the cleavage site of the activation peptide, which was referred to as protein C Tochigi.