A 24-yeаr-оld mаn is referred tо аn endоcrinologist for paroxysms of headaches associated with elevated blood pressure and palpitations. He is otherwise healthy, although he notes a family history of thyroid cancer. His physical examination is significant for the findings shown in Figures A, B, and C (see images). His thyroid is normal in size, but there is a 2.5 cm nodule palpable in the right lobe. On further workup, it is found that he has elevated plasma-free metanephrines and a normal TSH. Fine-needle aspiration of the thyroid nodule stains positive for calcitonin. The endocrinologist suspects a genetic syndrome. What is the most likely inheritance pattern?