RET and multiple endocrine neoplasia type 2A: They can occur as part of well-established hereditary syndromes, including multiple endocrine neoplasia type 2A and 2B, von Hippel–Lindau syndrome, neurofibromatosis type 1 and familial paraganglioma syndromes, caused by pathogenic variants in genes encoding Ret Proto-Oncogene (RET), Von Hippel Lindau protein (VHL), Neurofibromin 1 (NF1), or components of the succinate dehydrogenase (SDH) complex, respectively.