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. This evidence concerns the gene SDHB and hereditary pheochromocytoma-paraganglioma.