CYTOGENETICS OF MALIGNANT GLIOMAS .1. THE AUTOSOMES WITH REFERENCE TOREARRANGEMENTS

Autosomal chromosome abnormalities are far from always detectable and, when detected, far from fully consistent in malignant gliomas. In 15 of 41 malignant gliomas, we found autosomal chromosome aberrations ran ging from solitary trisomy to a wildly abnormal polyploid complement. The sequence of chromosome events appears to proceed from the normal t o the near-diploid state (via structural and numerical changes) to nea r-tetraploidy (via polyploidization), and finally toward near-triploid y (via chromosome loss and additional rearrangements), Characteristic chromosome changes of trisomy 7 and monosomy 10 were repeatedly found, usually together in the same cell clones. in only one case was trisom y 7 an isolated change. We observed structural rearrangements of chrom osomes 7 and 10 which may be of some use in mapping specific genes dup licated or deleted by the whole-chromosome changes of chromosomes 7 an d 10. Nonrandom structural changes of other autosomes, including chrom osomes 1, 5, and II, fit with the model of malignant glioma as a proce ss involving multiple genes. An unusual concentration of breakpoints i n 12q13, juxtaposing if to at least five other regions, reflects the p resence of genetic information in 12q13 important to the development o f malignant gliomas.