SDHD and pheochromocytoma: The major mutations associated with pheochromocytoma are von Hippel-Lindau gene (VHL), REarranged during Transfection (RET) proto-oncogene, neurofibromatosis type 1 gene (NF1), genes encoding four succinate dehydrogenase complex subunits (SDHx; i.e., SDHA, SDHB, SDHC, and SDHD genes) [24].