Genetic alterations involving chromosome 1p in children with neuroblastoma

Neuroblastoma is a common childhood tumor of the sympathetic nervous system, characterized by N-myc amplification and loss of heterozygosity (LOH) for sequences on chromosomes 1p, 11q and 14q. Using restriction fragment length polymorphism analysis, the constitutional and tumor genotypes were compared for LOH on 1p in 25 children with neuroblastoma at diagnosis: 19 in stages III-IV, 5 in stages I-II and one in IVs. The genetic alterations observed on chromosome 1p were frequent in the early and advanced stages. Thirty-three percent of the alterations were found in patients under the age of 1 year, and in one patient with IVs. It is concluded that 1p alterations were identified in children with neuroblastoma in early stages and infants and thus of no prognostic relevance. 1p genetic alterations may be early events in neuroblastoma.