The rarer inherited coagulation disorders: a review.

Of the inherited bleeding disorders, haemophilia A, haemophilia B and von Willebrand's disease make up together well over 80% of those registered with the UK Haemophilia Centre Directors. The common simple screening tests of coagulation may overlook some of the more rare disorders and it is clearly important that such uncommon bleeding disorders are excluded during the course of the investigation of children considered to be suffering from non-accidental injury. In this article, some of the rare inherited bleeding disorders are considered, including haemophilia B Leyden, deficiencies of factors VII, X, XI, and XII, as well as inherited defects of platelet number and function. Presenting features are described and recommendations regarding appropriate therapy given. In order to assist in advancing understanding of the biochemistry and molecular genetics of these disorders, clinicians are encouraged to share clinical information and, where appropriate, blood samples with interested research workers.