Strategy of Conclusion-Making for Paternity Testing with Short Tandem Repeats Genotyping / 中山大学学报(医学科学版)

ABSTRACT

[Objective] To propose a criterion for making conclusions on paternity tests based on STR genotyping. [Method] To use binomial distribution formula to calculate minimal numbers of STR loci that must be tested for different scenarios in paternity testing. [ Results ] We proposed a set of criteria for making STR paternity testing conclusions. For triplet tests, concluded "paternity positive" for the following four cases when the cumulative paternity index (PI) was greater than 10 000 1) no inconsistent STR locus was detected in 15 loci (PE > 0.571 4/locus) or 2) only one inconsistent STR locus was detected in 19 loci or 3) only two inconsistent STR loci were detected in 28 loci or 4) only three inconsistent STR loci were detected in 35 loci; otherwise, concluded "paternity negative" when at least four inconsistent STR loci had been detected. For single parent tests, concluded "paternity non-exclusive" for the following cases when the cumulative PI was greater than 10 000 1) no inconsistent STR locus was detected in 18 loci (PE>0.411/locus) or 2) only one inconsistent STR locus was detected in 29 loci or 3) two inconsistent STR loci were detected in 41 loci; concluded "paternity negative" when three or more inconsistent loci were detected. [Conclusion] Our experience has proven that these criteria are robust in STR paternity testing.