Abstract
Recently, a new syndrome involving somatic gain-of-function mutations in the gene encoding hypoxia-inducible factor α (HIF2A) was described by Pacak and Zhuang. This syndrome, only presenting in females, is characterized by congenital or early onset polycythemia, multiple paragangliomas (PGLs)/pheochromocytomas (PHEOs), and duodenal somatostatinomas.