Chromosome 19q deletions in human gliomas overlap telomeric to D19S219 and may target a 425 kb region centromeric to D19S112

Chromosome 19q harbors a tumor suppressor gene that is involved in astrocytoma, oligodendroglioma and mixed glioma tumorigenesis. We had previously mapped this gene to an approximately 5 megabase region of chromosome 19ql3.2-13.3 between APOC2 and HRC. To narrow the location of this tumor suppressor further, we studied 138 gliomas for loss of allelic heterozygosity at six microsatellite polymorphisms between APOC2 and HRC, including a newly described polymorphism in the ERCC2 gene. Allelic loss occurred in 48 gliomas (35%), including 25 of 41 oligodendroglial tumors (61%). Four cases had proximal breakpoints within the APOC2-HRC region, two telomeric to ERCC2 and two telomeric to D19S219. In addition, one of the latter tumors had an interstitial deletion between D19S219 and D19S112, a distance of only 425 kilobases surrounding the DM (myotonic dystrophy) gene. These findings suggest that the glioma tumor suppressor on chromosome 19q maps to 19ql3.3, telomeric to D19S219 and perhaps centromeric to D19S112. The data exclude a number of candidate genes from 19ql3.2-13.3, including a putative phosphatase gene and the DNA repair/metabolism genes ERCC1, ERCC2 and probably LIOl.