The study demonstrated that the 52 SNP-plex developed by the SNPforID consortium is a good alternative to standard short tandem repeat (STR) or variable number of tandem repeat (VNTR) investigations in relationship testing. The typical paternity indexes (PIs) were 10 to the fifth power to 10 to the sixth power for the trios and 10 to the third power to 10 to the fourth power for the child-father pairs. Using the SNP profiles from the randomly selected trios and 700 previously typed individuals, a total of 83,096 comparisons between mother, child, and an unrelated man were performed. On average, 9-10 mismatches per comparison were detected. Four mismatches were genetic inconsistencies, and five-six mismatches were opposite homozygosities. In only 2 of the 83,096 comparisons did an unrelated man match perfectly to a mother-child pair; for both cases, the PI of the true father was much higher than the PI of the unrelated man. The trios were also typed for 15 STRs and 7 VNTRs. The typical PIs based on 15 STRs or 7 VNTRs were 5-50 times higher than the typical PIs based on 52 SNPs. Six mutations in tandem repeats were detected among the randomly selected trios. In contrast, no mutations were found in the SNP loci. The descriptions of material and methods address the samples, STR analysis, VNTR analysis, SNP analysis, DNA sequencing, calculation of paternity indexes, and determination of mismatches between a child and an unrelated man. 3 tables, 3 figures, and 19 references