Pheochromocytoma-Paraganglioma Cluster 1 - VHL at 3p25

A 24-year-old male presents with episodic headaches, sweating, palpitations, and severe hypertension (BP 210/120 mmHg). Fundoscopy reveals bilateral retinal hemangioblastomas, and imaging shows bilateral adrenal masses with elevated plasma free metanephrines (predominantly normetanephrine). He has a history of resected cerebellar hemangioblastoma and a left renal mass suspicious for clear cell RCC. His mother died of metastatic RCC at age 38. Genetic testing identifies a germline inactivating mutation in the VHL tumor suppressor gene at the locus marked **A** in the diagram. Which of the following best explains the pathophysiology of pheochromocytoma in this patient?