Mutations observed at 13 CODIS STR loci in cases of paternity testing / 中国法医学杂志

ABSTRACT

Objective Mutations of 13 CODIS (Combined DNA Index System) STR core loci in 532 cases of paternity testing were observed in confirming paternity, the mutation rate and the mutation type were studied. Methods 587 cases of paternity testing were routinely carried out using AmpFe STR Profiler Plus and Cofiler PCR Amplification Kits. When one or two STR exclusions were found, then HLA system and other blood groups were tested by molecular typing, and sixteen STR loci were genotyped by using PowerPlexl6 PCR Amplification Kit. If necessary, the genotyping of Y chromosome specific STR and HLA allelic sequencing were added. Results 1052 meiosis were observed among the 532 cases in confirmed paternity, 18 mutation events were found in 17 paternity cases. Single-locus mutation was observed in 16 cases, and mutation at two STR loci was observed in one case. The observed mutational loci include D5S818, D3S1358, D16S539, CSFIPO, D21S11, D13S317, D7S820, vWA, D18S51 and FGA. The mutation rates for D18S51 and FGA loci were both 0.29% , which were the highest among the ten mutational loci. 11 events of paternal source mutations, 5 events of maternal source mutations and two events of indistinguishable mutations were observed in 18 STR mutational events. Conclusion When one or two STR exclusions were found in paternity testing, other more genetic markers must be detected as complement before making final conclusions.