factor XII deficiency
Last reviewed 01/2018
Hageman's disease is a rare disorder characterised by deficiency of Hageman factor (Factor XII). It is inherited as an autosomal recessive condition.
Laboratory analysis shows a markedly increased partial thromboplastin time but normal prothrombin time. Other tests are normal.
Patients do not bleed presumably because activation of the coagulation system occurs in vivo at the Factor XI level.
Diagnosis is by specific factor assay.