ALLELIC STATUS OF CHROMOSOME-1 IN NEOPLASMS OF THE NERVOUS-SYSTEM

By using five highly polymorphic markers, the allelic status of chromo some 1 was established in a series of 236 tumors of the nervous system , including all major histologic subtypes: gliomas, meningiomas, neuri nomas, neuroblastomas, medulloblastomas, etc. Loss of alleles at 1p wa s observed at significant frequencies in neuroblastomas (26% of cases) , meningiomas (32%), and malignant gliomas (37%) (primarily oligodendr ogliomas [94%1]). This anomaly was also detected in two of 23 neurinom as, two of three neurofibrosarcomas, one primary lymphoma, and two met astatic tumors of the brain. The analysis of tumors displaying partial 1p deletions suggests the existence of two distinct regions, 1p36 and 1p35-p32, in which loci nonrandomly involved in the development of ne urogenic neoplasms might be located.