A patient has a prolonged PT with a normal aPTT. Which deficiency is most consistent with this pattern?
1Factor VII✓ 정답
2Factor VIII
3Factor IX
4Factor XII
해설
An isolated prolonged prothrombin time points to the extrinsic pathway, and factor VII is the only factor unique to that pathway. Factors VIII and IX are intrinsic and prolong the aPTT, while factor XII prolongs the aPTT without causing bleeding. Memorize the four combinations of the two screening tests.