Genetic testing is suggested in patients with clinical or familial diagnosis, in first-degree relatives of MEN1 patients, starting at the age of 5 years, as well as in patients with suspicious or atypical manifestations, including multiglandular parathyroid disease, multiple PanNETs, gastrinoma, development of pHPT before the age of 30 years, and presence of two or more MEN1-associated tumors not meeting the clinical criteria for making the diagnosis [16]. This evidence concerns the gene MEN1 and gastrin-producing neuroendocrine tumor.