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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: INTRODUCTION, EXEGESIS. Meshes: Adolescent, Adult, Blood Proteins, DNA Mutational Analysis, Humans, Phenotype, Stroke, Thrombophilia, Venous Thrombosis.
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Protein Z: a new factor of thrombophilia? Context: Sometimes, in front of a clinical setting of thrombophilia, the biological findings are helpless. Therefore we suggest to test a protein Z deficiency. Protein Z is a vitamin-K dependent protein forming a complex with the Z protein-dependent protease inhibitor for inhibiting the activated factor X; so protein Z acts as a "natural low molecular weight heparin". The prothrombotic phenotype associated with protein Z deficiency includes early fetal losses (before the 20th week of gestation), early and relapsing venous thrombosis in patients with factor V Leiden mutation and somehow ischaemic stroke in young people.
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The protein Z deficiency seems to be associated with a particular prothrombotic phenotype including early fetal losses as well as early and relapsing venous thromboses in patients carrying the factor V Leiden mutation. It is unclear whether or not it plays a role as a thrombophilic factor especially in the arterial vascular field.