A child underwent a tonsillectomy at 6 years of age with no complications. He underwent a preoperative-screening for bleeding at the age of 12 years before an elective laparotomy, and was found to have a prolonged partial thromboplastin time but normal Prothrombin time. There was no family history of bleeding. The patient is likely to have. (AIIMS Nov 2012)
|A||Acquired vitamin K deficiency|
|B||Acquired liver disease|
|C||Factor XII deficiency|
|D||Mild hemophilia A|
Factor XII deficiency
1. Contact factors function at the step of initiation of intrinsic pathway of the clotting cascade and include the following:
2. Contact factors are
a. Factor XII
c. High Molecular Weight Kininogen (HMWK)
3. Deficiency of these factors is characterized by.
a. Isolated prolonged of PTT
b. Absence of clinical bleeding
4. These patients do not need treatment..
5. A paradoxical situation in which these is an extremely prolonged PTT but no evidence of clinical bleeding suggests a deficiency of contact factors.