We have studied nerve growth factor (NGF) receptors in 63 neuroblastoma tissues. We found DNA polymorphisms of TrkA consisting in C-->T transitions in tyrosine kinase domain at 6773, 7232 and 7301 nucleotides. Both C/T alleles were detected in tumors belonging to patients at stages 1, 2, 3 and 4 but not in 4S that expresses only the allele with C-->T. Furthermore, we detected a GT transversion resulting in a Gly-->Val substitution in a stage 4 and a stage 4S samples. We report the first evidence of TrkA polymorphism and point mutations in neuroblastoma.