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naveedmed
Forum Newbie Topics: 18 Posts: 171 |
To make an extra money, a healthy medical student participates in a hematology study. Because the study only involves having her blood drawn multiple times, she is not particularly concerned. A few weeks after her first blood test, the hematologist calls her into his office and asks if she is aware that she has a hematologic disorder. When she says she is not, he tells her that she should not be too concerned, inasmuch as there are usually no complications associated with the disorder, but that there is a risk of thrombosis. The student most likely has the deficiency of which of the following? A) Labile factor (V) B) Stable factor (VIII) C) Christmas factor (IX) D) Stuart factor (X) E) Hageman factor (XII)
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yunaAlly
| Forum Junior Topics: 1 Posts: 80
E
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GinaRMD |
The answer is E. Hageman factor (XII)
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naveedmed
| Forum Newbie Topics: 18 Posts: 171
Thanks yunaAlly and GinaRMD, the answer is E. Do you guys know the details of this disease?
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yunaAlly
| Forum Junior Topics: 1 Posts: 80
It was an educated guess,didnt know whole lot about it,but now i read this topic nicely and it's awesome given in wiki's. Thank you naveed for this qs.
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GinaRMD |
Hageman factor deficiency is a rare genetic blood disorder that causes prolonged clotting (coagulation) of blood in a test tube without the presence of prolonged clinical bleeding tendencies. It is caused by a deficiency of the Hageman factor (factor XII). When it is deficient, other blood clotting factors tend to compensate for its absence. This disorder is thought to be benign and usually presents no symptoms; it is usually only accidentally discovered through pre-operative blood tests that are required by hospitals. Of substantial recent interest is the role of antibodies to Factor XII in recurrent pregnancy losses. In other words, a lack of factor XII does not cause the affected person to bleed abnormally, but their blood takes longer than normal to clot in a test tube.Factor XII deficiency is usually found when clotting tests are done for routine screening. Tests may include: Factor XII assay Partial thromboplastin time (PTT) Treatment is generally unnecessary.
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naveedmed
| Forum Newbie Topics: 18 Posts: 171
Thanks Yuna and Gina, this is what i found out, The defect is deficiency of factor XII. This is inherited as autosomal recessive disorder. The paradoxical thrombogenic potential is explained by the fact that factor XII not only is required for coagulation (intrinsic pathway) but it also activates fibrinolytic system. Activated factor XII (XIIa) causes the activation of prekallikerin to kallikerin, which in turn causes activation of plasminogen to plasmin, which is fibrinolytic; with factor XII deficiency this system goes down and thus explaining the thrombosis. The coagulation defect produced by the factor deficiency can be compensated by other clotting factors (extrinsic pathway). These patient may have risk of thrombophlebitis and MI. Mild to moderate disease may not even be detected. In some it is usually detected during pre-op evaluation of patients ( greatly prolonged partial thromboplastin time).
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yunaAlly
| Forum Junior Topics: 1 Posts: 80
Thank you Naveed and GinaRMD.
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