congenital factor XI deficiency (MONDO_0012897) is an inherited bleeding disorder characterized by reduced levels and activity of factor XI (FXI) resulting in moderate bleeding symptoms, usually occurring after trauma or surgery. Also known as: PTA deficiency, Rosenthal factor deficiency, Rosenthal syndrome, Rosenthal's disease, factor XI deficiency, autosomal dominant, factor XI deficiency, autosomal recessive, haemophilia C, hemophilia C.