factor XI deficiency

an autosomal bleeding disorder caused by mutations in the F11 gene (locus: 4q35), which encodes factor XI. It is characterized by reduced plasma factor XI levels, recurring episodes of minor bleeding and mild bruising, menorrhagia, severe prolonged postsurgical bleeding, and prolonged recalcification and partial thromboplastin times. It is seen predominantly in persons of Ashkenazi Jewish ancestry; inheritance can be dominant or recessive. Called also plasma thromboplastin antecedent d., PTA d., hemophilia C, and Rosenthal syndrome.