Analysis of combinations of genetic changes that occur exclusively in patients may be a supplementary strategy to the single-locus strategy used in many genetic studies. The genotypes of 16 SNPs within susceptibility loci for neuroblastoma (NB) were analyzed in a previous study. In the present study, combinations of these genotypes have been analyzed. The theoretical number of combinations of 3 SNP genotypes taken from 16 SNPs is 15,120. Of these, 14,307 were found in 370 patients and 803 controls; 12,772 combinations were common to both patients and controls; 1,213 were found in controls only; and 322 combinations were found in patients only. Among the latter, a cluster of 24 combinations was found to be significantly associated with NB (P < 0.00001).