CLINICAL INVESTIGATION OF NEUROBLASTOMA WITH PARTIAL DELETION IN THE SHORT ARM OF CHROMOSOME-1

Several loci on the short arm of chromosome 1 (1p) have been reported as the consensus deleted regions for the putative suppressor genes of neuroblastoma by deletion mapping. The significance of deletion in 1p on the clinical features of neuroblastoma remains controversial. To cl arify the relationship between the clinical features of neuroblastoma cases and genetic status of 1p, we performed deletion mapping on 1p on samples obtained from 58 cases with neuroblastoma using 12 highly pol ymorphic microsatellite or minisatellite loci. Loss of heterozygosity of 1p was detected in 19 cases (33%) of primary tumors and in 21 cases (36%) when metastatic and recurrent sites were included. They were cl assified into two groups according to the 1p deletion pattern: interst itial deletion (group I, n = 11) and terminal deletion (group T, n = 1 0). The shortest region of overlap in group I ranged between FGR and D 1S170 (1p36.1-2). Clinically, all group I cases survived disease free, and none of these cases showed MYCN amplification. However, in group T, eight (80%) cases showed a large terminal deletion front D1S162 (1p 32-pter), including the shortest region of overlap of group I, and two (20%) showed a very terminal deletion from D1S160 (1p 36.3). Of the g roup T cases, only two survived disease free, and seven (70%) showed M YCN amplification. Thus, the candidates for the locations of neuroblas toma suppressor genes on 1p may involve at least two regions, which de monstrate different clinical features.