11q13.1

MEAI,SCG2

Multiple Endocrine Neoplasia type 1 or Wermer Syndrome

an inherited autosomal dominant predisposition to endocrine tumors, including parathyroids, endocrine pancreas, pituitary, adrenal glands, and the diffuse neuroendocrine tissues deriving from foregut; non-endocrine tumors have been observed in some MEN1 patients, including ependymoma, meningioma, cutaneous angiofibroma and lipoma, melanoma and rare visceral lesions such as rhabdomyosarcoma and leiomyoma; MEN1 is highly penetrant and more than 90% of gene-carriers will present biological and/or clinical signs of the disease affter the fifth decade; around 5-10% of patients have an agressive disease before age 20 no genotype-phenotype correlation were found to date in MEN1; nevertheless, most families with agressive NET have truncating mutations either in exons 2, 3, 9 or 10 but no studies have been able to find statistical evidence of this putative correlation; recent investigations suggested that some MEN1 families could express only primary hyperparathyroidism, so called familial primary hyperparathyroidism (FIHPT), an allelic variant of MEN1; MEN1 related FIHPT appears as a benign disease but hyperplasia and/or adenoma occur in all parathyroid glands; recent data suggest that this variant could be associated to missense mutations in exons 4 to 7 of the MEN1 sequence; nevertheless, such correlations remain uncertain an do not have clinical implications in medical practice; the identification of germline missense mutations in exons 4 to 7 must lead to an extensive biological and clinical screening of patients in order to exclude the occurrence of pancreatic and pituitary disease, as recently shown in a typical MEN1 family carrying a Leu264Pro in exon 5; approximately 10-15% of MEN1 families do not show any mutation in the known part of MEN1 sequence; clinical profile in these families do not differ from that of families with identified mutations and it is therefore possible that MEN1 mutations occur outside the coding sequence; deletion of part or full MEN1 sequence has been also suggested as a rare mechanism of germline mutation

it is mainly related to metabolic and organic complications of hormonal hypersecretion by tumoral cells (Zollinger-Ellison syndrome induced by gastrinoma, hyperinsulinism, hyperparathyroidism, hyeperaldoseronism, Cushing syndrome, hyperprolactinemia, acromegaly; more than 30-50% of digestive neuroendocrine tumors and those localized in thymus and bronchi have a metastatic potential