Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

MEN type 1 is an autosomal dominant disorder characterized by the combined occurrence of tumors of the parathyroids, anterior pituitary, and pancreatic islet cells. The MEN1 gene, which is located on chromosome 11q13, consists of 10 exons and encodes a 610-amino acid protein named MENIN. The observation of LOH involving 11q13 in MEN type 1 tumors and the inactivating germline mutations found in patients suggest that the MEN1 gene acts as a tumor suppressor, in keeping with the "two-hit" model of hereditary cancer. The second hit in MEN type 1 tumors typically involves large chromosomal deletions that include 11q13. However, this only represents one mechanism by which the second hit may occur, and the other mechanisms, such as intragenic deletions or point mutations that inactivate the gene, have not been reported in MEN type 1 tumors. We have therefore undertaken studies to search for such mutations in six MEN type 1 tumors (four parathyroid tumors, one insulinoma, and one lipoma) that did not have LOH at 11q13 as assessed using the flanking markers D11S480, D11S1883 and PYGM centromerically and D11S449 and D11S913 telomerically. This revealed four somatic mutations, which consisted of two missense mutations and two frameshift mutations in two parathyroid tumors, one insulinoma, and one lipoma. Thus, our results, which represent the first small intragenic somatic mutations reported in MEN type 1 tumors, provide further evidence that the role of the MEN1 gene is consistent with that of a tumor suppressor gene, as postulated by Knudson's "two-hit" hypothesis.

Original publication

DOI

10.1210/jcem.86.9.7844

Type

Journal article

Journal

J Clin Endocrinol Metab

Publication Date

09/2001

Volume

86

Pages

4371 - 4374

Keywords

Adult, Chromosomes, Human, Pair 11, DNA, Exons, Female, Gene Deletion, Humans, Loss of Heterozygosity, Male, Microsatellite Repeats, Multiple Endocrine Neoplasia Type 1, Mutation, Polymorphism, Genetic