Bi-allelic inactivation of the MEN1 tumor suppressor gene in human grade II astrocytoma

In humans and gene-targeted mice, loss of multiple endocrine neoplasia type 1 (MEN1) tumor suppressor gene function causes neuroendocrine tumors, frequently of the parathyroid and pituitary glands and the pancreas. The MEN1 gene product interacts with glial fibrillary acidic protein (GFAP) in the brain. We here demonstrate bi-allelic MEN1 inactivation in a grade II astrocytoma in an individual carrying a heterozygous MEN1 germ line deletion mutation (788del6). This tumor represents a novel, non-endocrine MEN1-phenotype, compatible with a role of MEN1-GFAP in glial oncogenesis. Clinically, a genetic predisposition to variant neoplasias should be considered in the management of MEN1 patients.