Although no somatic point mutation affecting SDHC has been reported to date in PPGL, postzygotic epimutations in the gene promoter region have been identified in patients with PGLs [47], Carney triad (GIST, pulmonary chondroma and PGLs) [48], and Carney-Stratakis syndrome (PGL and GIST) [49]. This evidence concerns the gene SDHC and gastrointestinal stromal tumor.