A 28-year-old man presents to the emergency room complaining of dull retrosternal chest pain during his work as a carpenter. Usually, the pain lasts a few minutes at a time and is relieved by rest. But today it is unrelenting and unresponsive to nitroglycerin. He reports that his father and his paternal uncle had heart attacks in their late twenties. The patient has no history of hypertension, diabetes, or tobacco use. On physical examination, you notice fat deposits on both eyelids and bilateral tendon xanthomas. Coronary angiogram reveals a multivessel coronary artery disease. Preoperative fasting lipid panel is significant for a total cholesterol 356 mg/dL, high-density lipoprotein (HDL) cholesterol 39 mg/dL, low-density lipoprotein (LDL) cholesterol 286 mg/dL, and triglycerides 111 mg/dL. In this disorder, mutations affect which of the following genes?
