MOLECULAR AND CYTOGENETIC ANALYSIS OF CHROMOSOME-9 DELETIONS IN 75 MALIGNANT GLIOMAS

A deletion mapping analysis of chromosome 9 has been performed on a se ries of 75 samples derived from malignant gliomas. A total of 27 tumor s displayed different deletions for the loci studied (D9S1, NRASL1, D9 S18, IFNA, and IFNB1). In most instances, losses involving the markers located on the short arm of chromosome 9 were observed, and only two samples were characterized by losses of the short and long arms. Eithe r partial or complete homozygous deletions of IFN genes were observed in 15 cases, and 12 other samples showed hemizygous deletions for thes e genes. The results show that the 9p abnormalities are not exclusive to high-grade astrocytic tumors, as some low-grade samples (two astroc ytomas grade II and six oligodendrogliomas) displayed this anomaly whi ch, in a few instances, was the sole abnormality detected. (C) 1994 Wi ley-Liss, Inc.