A 15 year old boy presents with acute onset of right flank pain, which developed after physical exercise. Physical examination demonstrates an area of ecchymosis in the right flank that is tender to palpation. The patient has a lifelong history of easy bruising. Sibling has same symptom. The serum level of clothing factor VIII is less than 2% of normal. Which of the following is the most likely underlying mechanism for bleeding tendency in this patient?
X-linked recessive disorder of blood clotting that results in spontaneous bleeding, particularly into joints, muscles and internal organs and easy brusing.
Classic hemophilia results from mutations in the gene encoding factor VIII
Intrinsic pathway affected.
Factor VIII a complex is the most important activator of factor x required for conversion of prothrombin to thrombin.
Deficiency of vitamin K
Genetic defect involving the factor VIII gene
Decreased nepatic synthesis of multiple coagulation factors
Circulating antibodies directed against factor VIII