Study Of STR Genetic Polymorphism In Minnan Area Han Population And Application Of Full Sibship Analysis Based On GlobalFiler Detection System

Objective:To analysis genetic polymorphism of 21 autosomal short tandem repeat Loci from Minnan Area Han groups based on GlobalFiler kits,to assess the value of GlobalFiler kits in forensic practices.To evaluate the power of the GlobalFiler kit in sibship analysis by using ITO method,Fisher discriminant function method and IBS method,provided references for daily sibling identification.Method:?1?Blood samples of 1000 unrelated Han individuals from Minnan Area were collected,genomic DNA was extracted by the Chelex-100 protocol.?2?Genomic DNA was amplified using GlobalFiler Express PCR Amplification Kits.?3?Amplification products were analyzed by capillary electrophoresis and sequencing,STR genotypes of21 STR loci were obtained.?4?Analysis the STR genotypes by analysis software,to obtain allele frequencies and other forensic parameters.Population differentiation was also estimated between the Minnan Area Han and other Chinese populations.?5?Blood samples of 50 pairs of full-siblings and 150 pairs of no-related random from Minnan Area Han group were collected,followed the procedure?1?to?3?to obtain genotypes of each individual.?6?Cumulative full sibling index were calculated in full-sibling pairs and no-related random pairs by using ITO method.?7?Summed up the number of locus with two alleles shared,one allele shared and no allele shared at each pair,according to this result established discriminant function.?8?IBS were calculated in full-sibling pairs and no-related random pairs.Results:?1?1000 individuals from the Minnan Area Han groups were successfully obtained genotypes of the total 21 autosomal STR loci without observing null allele and triallele,274 kinds of alleles were found.?2?21 autosomal STR loci were tested for Hardy-Weinberg equilibrium by chi-square test,the P values were all greater than 0.05,the linkage disequilibrium test of STR loci located on the same chromosome showed that the P values were all greater than 0.05.?3?Forensic genetic parameters of GlobalFiler system 21 STR loci in Minnan Area Han group:power of discrimination?DP?was ranged from 0.7804 to 0.9925,polymorphism information content?PIC?was ranged from 0.5410 to 0.9391,power of exclusion?PE?was ranged from 0.2909 to 0.8878,observed heterozygosity?HO?was ranged from 0.600 to 0.9449,expected heterozygosity?HE?was ranged from 0.5982 to 0.9427,matching probability?MP?was ranged from 0.007 to 0.220.?4?At 17 shared STR loci,the significant differences were found between the Minnan Area Han population and Guangdong Han population at 3 STR loci,Tianjin Han population at 3 STR loci,Hennan Han population at 7 STR loci,Yunnan Miao population at all 17 loci,Xinjiang Kazakh population at 13 loci,Xinjiang Uyghur population at 16 loci.?5?The value of cumulative full sibling index?CFSI?was ranged from 1.38 to 2.14x10¹⁹ in full-sibling pairs and 4.19x10^-9 to 2.60 in unrelated pairs.As CFSI>3 for full sibling,CFSI<1 for unrelated individuals,the detection efficiency of this standard was 99%.?6?The discriminant functions of FS-UI were established using the Fisher discriminant analysis method,the correct percentage of discriminant functions was 98.5%.?7?IBS was ranged from 20 to 42 in full-sibling pairs and 8 to 21 in unrelated pairs,suggested that IBS?23for full sibling;IBS?16 for unrelated individuals,the detection efficiency was approximately equal to 0.900.Conclusions:?1?GlobalFiler system 21 autosomal STR loci were all in accordance with Hard-Weinberg equilibrium and without Linkage disequilibrium in Minnan Area Han Population.TH01 loci had poor polymorphism,TPOX loci had lower power of identify and poor polymorphism,other 19 STR loci had high power of identify and high polymorphism.The cumulative power of exclusion of GlobalFiler system 21 STR loci was 0.999999999,the cumulative match probability was 7.72×10^-26,showed a high forensic application.?2?The significant differences were found between the studied population and other Chinese populations,showed the genetic difference of STR,the allele frequency in Minnan Area Han population enriched the Chinese DNA database.?3?ITO method,discriminant function method and IBS method were used to explore the application of GlobalFiler system in sibship analysis.Three identification standards will provide reference for daily sibship testing.