An APTT on a 46-year-old male patient admitted for minor sur…
An APTT on a 46-year-old male patient admitted for minor surgery is markedly abnormal, whereas the PT is within normal range. The patient has no clinical manifestations of a bleeding problem and has no personal or family history of bleeding problems, even following dental extraction. The prolonged APTT is corrected with a 1:1 mixing study with normal plasma. Based on these laboratory results and the clinical history, what factor deficiency would be expected?