Inherited protein C deficiency with acute ischemic stroke in a young adult: a case report.

Hereditary protein C deficiency is inherited primarily as an autosomal dominant trait with incomplete penetrance. Arterial thrombosis, especially of the intracranial arteries, due to this deficiency is relatively rare. A 31-year-old man was admitted to our department because of sudden onset of neurological symptoms. Magnetic resonance imaging of the brain disclosed an acute ischemic infarction of the area supplied by the left middle cerebral artery. Protein C antigen was 40.7% (77-129%) and protein C activity was 46.3% (70-140%). No other possible associated causes of stroke were present. A survey of his relatives for protein C deficiency showed this deficiency in his mother, brother, sister and nephews. Protein C concentrations should be determined in cases of ischemic stroke in all young patients with no other major risk factors. Once protein C deficiency is detected, a search for protein C deficiency in the patient's relatives should be performed to prevent the occurrence of ischemic strokes.