VHL and multiple endocrine neoplasia type 2: It has been demonstrated that patients with von Hippel-Lindau disease (VHL; VHL gene), multiple endocrine neoplasia type 2 (MEN 2), and paragangliomas syndromes types 1 and 4, which are caused by mutations in the succinate dehydrogenase (SDH) subunit D (SDHD) and B (SDHB) genes, respectively, are more likely to develop bilateral pheochromocytomas, which are frequently heritable [4].