SDHD and hereditary pheochromocytoma-paraganglioma: 183 (30.6%) patients—germline mutation in SDHx gene, frequency (decreasing): SDHD, SDHB, SDHCSix factors were found to suggest the presence of a germline mutation: age (<40 years), gender, number of tumors (single or multiple), tumor biology (malignant or benign HNP), previous chaperone tumors and family history of HNPGL or pheochromocytoma