Amyloidosis Associated with Factor X (Stuart) Deficiency

Abstract
A 53-year-old male with a bizarre fatal systemic disease and hepatic amyloidosis had a prolonged Quick pro-thrombin time, due to an isolated deficiency of Factor X (Stuart). Acquired deficiencies of Factor X alone have been reported three times in association with amyloidosis (2,3,4), and only once in its absence (12). In view of this association, and the rarity of acquired isolated Factor X deficiency, a specific effect of amyloid deposition on Factor X was considered.