Novel Gene Variants in a Nationwide Cohort of Patients with Pheochromocytoma and Paraganglioma.

Pheochromocytomas (PCCs) and paragangliomas (PGLs), denoted PPGLs, are rare neuroendocrine tumours and are highly heterogeneous. The phenotype-genotype correlation is poor; therefore, additional studies are needed to understand their pathogenesis. We describe the clinical characteristics of 63 patients with PPGLs and perform a genetic study. Genetic screening was performed via a targeted gene panel, and clinical variables were compared among patients with a positive molecular diagnosis and negative ones in both PCC and PGL cohorts. The mean age of patients with PCC was 50.0, and the mean age of those with PGL was 54.0. Disease-causing germline variants were identified in 16 individuals (25.4%), twelve and five patients with PCC and PGL, respectively. Genetically positive patients were younger at diagnosis in both cohorts. Variants in genes associated with either isolated PPGLs or syndromic forms of the disease were detected in a cohort of PPGLs. We have identified novel variants in known genes and set the importance of genetic screening to every patient with PPGLs, with a special focus on the young. A longer follow up of patients with variants in genes associated with syndromic forms is of clinical value.