HAF Deficiency or Hageman Factor Deficiency is a rare genetic blood disorder that leads to prolonged clotting or coagulation of blood without the presence of prolonged clinical bleeding tendencies. It is also known as factor XII deficiency. Previously it was thought that factor XII is needed for blood clotting and when it is deficient, other blood clotting factors will compensate for its absence. Factor XII is also known as Hageman factor which is a plasma Glycoprotein.

The condition can also be acquired and may be temporary. The incidence of the disease is greater in Asian patients. The disease follows an autosomal recessive trait. The gene map locus has been established as 5q33-ter. Factor XII is a contact factor in the kallikrien kinin or the plasma system. The patients don’t have any bleeding disorders as the coagulation is activated by other cofactor. The disorder is benign in nature and there are no symptoms generally i.e. the disease is asymptomatic. The diagnosis of the disease is serendipitous. The disease is diagnosed accidentally generally during routine blood examinations or during preoperative blood assessments. The disease is also found in women who have recurrent abortions and the etiology has been put as the role of some antibodies.

Diagnosis

• Partial Thromboplastin Time (PTT) is prolonged in the patients
• Activated Partial Thromboplastin Time (aPTT) is prolonged in these patients

Complications

• Recurrent Abortions due to antibody formation
• Some cases with minor blood losses are reported but is of rare occurrence
• Due to the inactivation of the fibrinolysis the patients with this state carry a higher risk for the development of the Thromboembolism.