Molecular genetic studies in the past few years have identified >10 genes involved in the pathogenesis of pheochromocytomas and paragangliomas, including RET oncogene, involved in the pathogenesis of multiple endocrine neoplasia (MEN) 2A and 2B, von Hippel-Lindau tumor-suppressor gene, neurofibromatosis type 1 gene, succinate dehydrogenase, THEM127, and several others.
In multiple endocrine neoplasia (MEN) 2a, the expression of the SDH genes and VHL mRNA was significantly higher than that observed in adrenal or extra-adrenal pheochromocytoma.
We mapped the MenX locus to the distal part of rat chromosome 4, excluding the homologs of the genes responsible for the MEN syndromes (RET and MEN1) and syndromes with an endocrine tumor component (VHL and NF1).
Molecular defects have also been identified in syndromes related to the MENs, like Peutz-Jeghers syndrome (PJS) (the STK11/LKB1 gene), and Cowden (CD; the PTEN gene) and von Hippel-Lindau disease (VHLD; the VHL gene).