Review Question - QID 109773

A 39-year-old man presents to the emergency room for epistaxis. He reports having frequent nosebleeds over the past 48 hours. He also reports a constant pounding headache over the same timeframe. He is accompanied by his wife who reports that he has seemed “off” lately, frequently forgetting recent events and names of his friends. His past medical history is notable for hypertension and rheumatoid arthritis. He takes lisinopril and methotrexate. He has a 10 pack-year smoking history and drinks 2-3 beers per day. His temperature is 101.1°F (37.3°C), blood pressure is 145/90 mmHg, pulse is 110/min, and respirations are 18/min. On exam, he appears pale, diaphoretic, and has mild scleral icterus. His spleen is palpable but non-tender. Laboratory analysis is shown below:

Hemoglobin: 8.9 g/dL
Hematocrit: 26%
Leukocyte count: 4,900/mm^3 with normal differential
Platelet count: 25,000/mm^3

Prothrombin time: 14 seconds
Partial thromboplastin time (activated): 27 seconds
International normalized ratio: 1.1
Bleeding time: 9 minutes

This patient has a condition that is caused by a defect in which of the following processes?