Combined clotting factor deficiencies: experience at a single hemophilia treatment center.

We describe a series of patients with combined factor deficiencies and von Willebrand's disease (VWD) at one haemophilia treatment centre. Although the incidence of VWD is at least 1% in the general population, combined coagulation defects have been infrequently described in the medical literature and are likely under diagnosed. This entity should be considered in patients with a known factor deficiency and either an unexpectedly severe bleeding phenotype, or bleeding that is unresponsive to factor replacement.