Related Experiment Videos
Inherited haemorrhagic disease with abnormal prothrombin consumption
Insights
This study identifies a rare bleeding disorder in a child caused by abnormal prothrombin, a key clotting protein. This molecular defect leads to impaired blood clot formation, explaining the patient's excessive bleeding.
Area of Science:
- Hematology
- Molecular Biology
- Biochemistry
Background:
- Investigating inherited bleeding disorders is crucial for effective diagnosis and management.
- Prothrombin (Factor II) plays a central role in the coagulation cascade, essential for hemostasis.
- Disorders of prothrombin can lead to significant hemostatic defects, including excessive bleeding.
Observation:
- A 4-year-old boy presented with severe bleeding post-surgery, recurrent hematomas, and epistaxis.
- Standard coagulation tests were normal, except for abnormal prothrombin consumption tests.
- The patient's father also exhibited an abnormal prothrombin consumption index, suggesting a familial trait.
Findings:
- Prothrombin conversion was significantly delayed, taking up to 24 hours to reach completion.
- Plasma prothrombin levels and electrophoretic mobility were normal.
- Crossed immunoelectrofocusing revealed an abnormal isoelectric point (pI) in purified prothrombin, indicating a molecular anomaly.
Implications:
- The findings suggest the presence of an abnormal prothrombin molecule responsible for impaired coagulation.
- This molecular defect in prothrombin can cause a distinct bleeding disorder.
- Further characterization of this abnormal prothrombin is needed for precise diagnosis and potential therapeutic strategies.
Abstract:
The propositus is a 4-year-old boy who presented with a history of excessive bleeding after surgical procedures as well as haematomas and epistaxis. The defect in haemostasis consisted in an anomaly of the prothrombin consumption tests as the only abnormality while all the other conventional coagulation and fibrinolysis tests as well as platelet function tests were normal. The father of the propositus had no previous history of excessive bleeding but was found to have an abnormal prothrombin consumption index. The reaction to prothrombin conversion, normal at onset, slowed down to less than normal and did not reach completion until 24 h. The in vivo studies suggest that the effect does not act on the interaction between platelet phospholipid and plasma. The factor II dosage and the electrophoretic mobility of prothrombin of the plasma were normal; nevertheless when studying the purified prothrombin by means of crossed immunoelectrofocusing there appeared an anomaly of pI. This result suggests the possible existence of an abnormal prothrombin molecule responsible for a slow prothrombin conversion.