Recurrent ischemic strokes caused by hereditary protein S deficiency from a novel PROS1 mutation: a case report.

BACKGROUND

Protein S deficiency (PSD) is an inherited thrombophilia caused by functional defects in protein S encoded by the PROS1 gene. Mainly manifesting as venous thromboembolism, PSD is not considered as a definitive cause of arterial thrombosis. However, there are several cases reporting ischemic stroke in patients with PSD, and anticoagulants were given as treatment.

CASE PRESENTATION: We present a patient with four ischemic strokes during the past 11 years, which recurred despite secondary prevention. Brain magnetic resonance imaging showed ischemic lesions in bilateral basal ganglia and paraventricular regions, as well as the left pons. After thrombophilia screening, the patient was diagnosed with hereditary PSD with a heterozygous PROS1 c.1961 C > A (p.A654D) mutation. He was treated effectively with clopidogrel and rivaroxaban.

CONCLUSIONS

Hereditary PSD should be suspected in patients with recurrent ischemic strokes and a family history of thrombotic events. Anticoagulation treatment is warranted if evidence strongly suggests a contribution of PSD to ischemic strokes.