ANALYSIS OF THE NEUROFIBROMATOSIS-2 GENE IN HUMAN EPENDYMOMAS AND ASTROCYTOMAS

Ependymomas and astrocytomas commonly have allelic losses of chromosom e 22q, which suggests the presence of a glioma tumor suppressor gene o n 22q. A candidate tumor suppressor gene on 22q is the neurofibromatos is 2 (NF2) gene since NF2 patients have an increased susceptibility to ependymomas and astrocytomas. Using single strand conformation polymo rphism analysis and direct DNA sequencing, we screened 8 ependymomas a nd 30 fibrillary astrocytomas from non-NF2 patients for mutations in t he coding sequence and portions of the 3' untranslated region of the N F2 gene. Only one mutation was detected, a single base deletion in NF2 exon 7 from a spinal ependymoma, which had also lost the wild-type al lele. These results suggest that the NF2 gene may be important in the formation of some ependymomas but the NF2 gene is probably not the cri tical chromosome 22q tumor suppressor gene involved in astrocytoma tum origenesis.