We conclude that many "hyperplastic" parathyroid tumors in familial MEN-1 are in fact monoclonal and may progress or even begin to develop by inactivation of the MEN-1 gene (at 11q13) in a precursor cell.
Extensive experience from patients with gastrinoma as part of the multiple endocrine neoplasia type 1 (MEN 1) syndrome has revealed that MEN 1-gastrinoma patients show important differences from patients with sporadic gastrinoma.
This suggests that in patients with the Zollinger-Ellison syndrome and MEN-1, the promotion of fundic argyrophil carcinoid tumors results from the inactivation of the two copies of MEN-1 gene and that fundic argyrophil carcinoid tumors may be included in the spectrum of MEN-1-related tumors.
To identify a gene responsible for multiple endocrine neoplasia type 1 (MEN1), we attempted to isolate potentially transcribable fragments from cosmid clones derived from a region on chromosome 11q13 where genetic linkage studies and analyses of loss of heterozygosity in MEN1-associated tumors have localized the MEN1 gene.
One such mutation has been reported in a GH-producing tumour from a patient with multiple endocrine neoplasia type 1 (MEN 1) although mutations have not been reported in other tumours associated with MEN 1.
A case of exocrine pancreatic adenocarcinoma presenting as the terminal event in a woman with a long standing history of MEN-1 syndrome and multiple endocrine tumours of the pancreas was investigated for possible allelic losses at the MEN-1 gene locus using restriction fragment length polymorphisms (RFLPs) closely linked to the MEN-1 gene and polymerase chain reaction (PCR) for D11S533 locus.
Here we describe the localization of the MEN1 gene to a 900-kb region, based on linkage analysis in affected families and deletion mapping of MEN1-associated tumours.
We conclude that the pathogenesis of GH-secreting adenomas in MEN-1 is influenced by secondary factors acting in synergy with the well-documented primary MEN-1 gene defect on chromosome 11q13.
Definition of the minimal MEN1 candidate area based on a 5-Mb integrated map of proximal 11q13. The European Consortium on Men1, (GENEM 1; Groupe d'Etude des Néoplasies Endocriniennes Multiples de type 1).
Primary HPT is also a feature of several hereditary diseases e.g. multiple endocrine neoplasia type 1 and type 2A (MEN1 and 2A), familial hypocalciuric hyperparathyroidism (FHH), the HPT-jaw tumor syndrome (HPT-JT), and familial isolated HPT.
Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant familial cancer syndrome characterized by parathyroid, pancreatic, and anterior pituitary tumors.
To elucidate the potential etiological role of the MEN1 gene in pituitary tumorigenesis, 39 sporadic pituitary adenomas from 38 patients and 1 pituitary adenoma from a familial MEN1 patient were examined for MEN1 gene mutations and allelic deletions.
Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterised by tumours of the parathyroids, pancreas and anterior pituitary that represents one of the familial cancer syndromes.
The lower rate of 11q13 LOH in MEN1-associated and sporadic gastrinomas and sporadic insulinomas as compared to MEN1 nongastrinomas may reflect alternative genetic pathways for the development of these tumors or mechanisms of the MEN1 gene inactivation that do not involve large deletions.
Multiple endocrine neoplasia type I (MEN1) is an inherited syndrome that results in parathyroid, anterior pituitary, and pancreatic and duodenal endocrine tumors as well as foregut carcinoids in affected patients.
Southern blot analysis with constitutional DNA from probands of 14 independent MEN 1 families and DNA from four MEN 1 tumor specimens did not reveal any structural abnormality of the NF-kappa B3 gene.
MEN1 was confirmed in the family by linkage analysis using MEN1-linked microsatellite markers and by identification of a nonsense mutation in the MEN1/menin gene.
To confirm this finding we used PCR from genomic DNA and direct sequencing to analyze exons 2 through 10 of the menin gene in eight patients from four pedigrees with MEN-1 syndrome or an affected relative.
To assess the role of the MEN-1 gene in the pathogenesis of tumors less commonly associated with MEN-1, we employed a large number of highly informative polymorphic markers closely linked to the MEN-1 gene to study a series of 13 such tumors from subjects with FMEN-1 for LOH at 11q13.
These findings suggest that, because of the absence of an obvious founder effect, the entire MEN1 gene region should be examined for germline mutations in the probands of MEN1 and related syndromes in Japanese families.
These findings indicate that inactivation of both copies of the MEN1 gene are not sufficient for parathyroid tumor development in MEN 1 patients and that tumor suppressor genes, other than the MEN1 gene on chromosome 11 or on other chromosomes, can be involved in the pathogenesis of parathyroid tumorigenesis in MEN 1 syndrome.