[Forensic Investigation of Goldeneye™ DNA ID 22NC Kit].

OBJECTIVE: To investigate the genetic data of 21 autosomal STR included in Goldeneye™ DNA ID 22NC Kit in Chinese Han nationality and to evaluate the forensic application. METHODS: By detected 500 unrelated healthy individuals in Chinese Han nationality of East China with Goldeneye™ DNA ID 22NC Kit, allele frequencies, population genetics parameters and linkage disequilibrium information of the 21 autosomal STR were statistically analyzed. RESULTS: In the 21 autosomal STR, no deviations from Hardy-Weinberg equilibrium were detected and all loci were independent form each other. DP values of 21 autosomal STR were all above 0.85, and the combined discrimination power was 1-3.616 5 x 10(-26). Combined mean exclusion chance of this system in duo cases was 1-2.786 81 x10(-6), in trio cases was 1-8.545 82 x 10(-1). CONCLUSION: Twenty-one autosomal STR included in Goldeneye™ DNA ID 22NC Kit are highly polymorphic in the Han nationality. Combined with Goldeneye™ DNA ID 20A Kit, the kit can satisfy the needs for full-sibling testing and facilitate the solution of this kind of case tools.

[Forensic validation of goldeneye? DNA ID 26Y system].

OBJECTIVE: To perform the validation and analysis of forensic parameters of Goldeneye DNA ID 26Y system. METHODS: Based on the validation rules of Scientific Working Group on DNA Analysis Methods (SWGDAM), the kit was assessed from several parts, as test of PCR system, reproducibility, accuracy, and sensitivity, etc. And Y-STR loci of 517 unrelated healthy individuals from Eastern China were genotypes by this kit. The distribution and frequency of haplotype were calculated and forensic parameters of the kit were assessed. RESULTS: The complete profiles can be obtained even when the PCR reaction volume with 6.25 microL. And correct profile was obtained with DNA down to 125 pg. No reproducible peaks were detected with the DNA of common animals and microorganism with the kit. For the male-male mixture testing, average 70% of the minor alleles were obtained when the ratios of 1:19 and 19:1. For the male-female mixture testing, results showed that the sensitivity of the kit was no compromised with the addition of female samples. CONCLUSION: The validation studies demonstrated that Goldeneye DNA ID 26Y system has good sensitivity and specificity, and suitable for mixture testing. The polymorphism of 26 Y-STR loci included in this kit are good for forensic application.

[Universal algoritihms for paternity index in trios and its extended application].

OBJECTIVE: To introduce an universal algorithm for kinship index between a baby and a random person with biologic mother reference. METHODS: Based on the formulas of paternity index in trios (PIT), common factors shared in these formulas were deduced following reconstructions of these formulas with the common factors. Universal algorithms for other common kinship indices, such as grandparental index (GI), half sibling index (HSI), avuncular index (AI) and first cousin index (CI1st), were investigated according to avuncular index rule and the coefficient of relationship (r). RESULTS: The common factor shared in the formulas for PI(T) calculation was 1 plus reciprocal of the frequency of the allele with identity by state between the alleged father and the detected baby. Two general formulas for PI(T), GI, AI, HSI and CI1st with biologic mother reference were successfully established with the common factor and r value. CONCLUSION: The calculation was simplified with the universal algorithms for common kinship indices between random person and the baby with biologic mother reference and the batch arithmetic operation with the universal algorithms can be easily realized with programming.

[Establishment of universal algorithms for commonly used kinship indices between two individuals].

OBJECTIVE: To establish universal algorithms for commonly used kinship indices between two individuals. METHODS: Based on the formulas of paternity index in duos(PID), full sibling index(FSI), half sibling index (HSI), avuncular index (AI), grandparental index (GI) and first cousin index (CI1st) deduced from ITO method, the common factors, 1 plus reciprocal of the frequency of the allele with identity by state between the two individuals, shared in these formulas were abstracted with induction method, following with reconstruction of these formulas with the common factor and the coefficient of relationship (r). RESULTS: A universal algorithm for PI(D), HSI, AI, GI and CI1st, was developed with the common factor and r value according to the heterozygosity of the two individuals. Meanwhile, a group of two formulas for FSI calculation was also established according to the individuals' heterozygosity. CONCLUSION: The universal algorithms for the 6 types of kinship indices are practical in corresponding kinship determination and the batch arithmetic operation with the universal algorithms can be easily programmed.

[Application of multiple polymorphism genetic markers in determination of half sibling sharing a same mother].

OBJECTIVE: Determination strategies for half sibling sharing a same mother were investigated through the detection of autosomal and X-chromosomal STR (X-STR) loci and polymorphisms on hypervariable (HV) region of mitochondrial DNA (mtDNA). METHODS: Genomic DNA were extracted from blood stain samples of the 3 full siblings and one dubious half sibling sharing the same mother with them. Fifteen autosomal STR loci were genotyped by Sinofiler kit, and 19 X-STR loci were genotyped by Mentype Argus X-8 kit and 16 plex in-house system. Polymorphisms of mtDNA HV-I and HV-II were also detected with sequencing technology. RESULTS: Full sibling relationship between the dubious half sibling and each of the 3 full siblings were excluded based on the results of autosomal STR genotyping and calculation of full sibling index (FSI) and half sibling index (HIS). Results of sequencing for mtDNA HV-I and HV-II showed that all of the 4 samples came from a same maternal line. X-STR genotyping results determined that the dubious half sibling shared a same mother with the 3 full siblings. CONCLUSION: It is reliable to combine three different genotyping technologies including autosomal STR, X-STR and sequencing of mtDNA HV-I and HV-II for determination of half sibling sharing a same mother.

[Application of the number of allele shared among autosomal STR loci in full sibling identification].

OBJECTIVE: To establish and evaluate the method of full sibling identification based on the number of allele shared among autosomal STR Loci. METHODS: Two hundred and eighty full sibling pairs and 2,003 unrelated individual pairs were genotyped in 15 STR loci with Identifiler Kit, and the number of allele shared among the 15 STR loci (S15) and full sibling index (FSI) were calculated. Fisher discriminant functions were established with SAS 8.2 software based on S15, the power of which were compared with ITO method. RESULTS: The distribution of S15, in full sibling pair group and unrelated individual pair group were in accord with normal distribution. The established Fisher discriminant functions for each group were Z(FS)= 3.26970S15-31.51174 and Z(UI)=1.70058S15-8.524 11, respectively. The average error of probability in sibling and unrelated pair group was 0.0298. There was no statistically significant difference on the power of full sibling discriminant between the method based on the number of allele shared among the 15 STR loci or the CODIS 13 STR loci and the ITO method. CONCLUSION: The method based on the number of allele shared among the 15 STR loci in full sibling identification is convenient, credible, easy to handling and unaffected by the allele frequency of STR loci.

[The evaluation of Identifiler system in paternity testing].

OBJECTIVE: To evaluate the power of Identifiler System for paternity testing. METHODS: A total of 3 277 paternity testing cases were studied using Identifiler System. The exclusion power and mutation rates of the Identifiler System were analysed in the paternity testing. RESULTS: The cumulated power of exclusion was 0.999 998 827, and the cumulated discriminating power was 0.999 999 999 999 999 98, respectively. Of the 3 277 cases, paternity was confirmed in 2 863, but excluded in 347. Among this paternity testing, mutations involving a single STR locus were observed in 65 cases, while mutations involving 2 STR loci were observed in 2 cases. CONCLUSION: The Identifiler System is powerful and reliable for paternity testing.

[Analysis of appropriate amount of template DNA for sinofiler kit by real time quantitative PCR technique].

OBJECTIVE: To explore the appropriate amount of template DNA for Sinofiler Kit. METHODS: The DNA samples with ideally genotyped results by Sinofiler Kit were detected by real-time quantitative PCR assay. RESULTS: It was shown that 1.29-1.51 ng of template DNA in 12.5 microL reaction volume was optimal for STR genotyping with Sinofiler Kit. CONCLUSION: Real time quantitative PCR is an accurate and necessary technique for detection of appropriate amount of template DNA for different kits.

[Application of D6S1043 and D12S391 loci in forensic paternity testing].

OBJECTIVE: The aim was to investigate the polymorphisms of D6S1043 and D12S391 loci among Han population and evaluate their values in paternity testing. MERTHODS: By using fluorescence dye-labeled primers and capillary electrophoresis, the allele frequencies of the two STR loci among 192 unrelated individuals were investigated. RESULTS: Twelve alleles were observed in both D6S1043 and D12S391 loci. The ranges of allele frequencies were from 0.0026 to 0.1719 and from 0.0026 to 0.2292, respectively. The discrimination power of D6S1043 and D12S391 were 0.9656 and 0.9510. The Average exclusion probability in paternity testing for duos were 0.573 and 0.510. The Average exclusion probability in paternity testing for trios were 0.731 and 0.679, respectively. The genotypes frequencies met Hardy-Weinberg equilibrium expectation. CONCLUSION: The results show that D6S1043 and D12S391 have high values in forensic paternity testing.

SNP genotyping by multiplex amplification and microarrays assay for forensic application.

OBJECTIVE: Research on the application feasibility of SNP genotyping for forensic identification by microarrays. METHODS: Oligonucleotide microarrays which could detect 34 different SNPs were used. After hybridization and washing, the arrays were scanned and fluorescence intensities analyzed using Microarray software. Population studies on 34 SNP loci were carried out in a sample of 109 unrelated Chinese Han individuals using oligonucleotide microarrays for genotype detection. The method was also applied to cases. RESULTS: According to the results of population studies, no deviations from Hardy-Weinberg equilibrium could be found. Among the 34 loci, 3 SNPs were low informative, 4 were medium informative and 27 were high informative. The combination discrimination power (CDP) of the 31 optimal polymorphic SNPs was 0.9999999999979. The matching probability was 2.13 x 10(-12). The average exclusion probability in paternity testing for duos was 0.9609. The average exclusion probability in paternity testing for trios was 0.9970. CONCLUSION: The data and case application demonstrated that SNP typing by oligonucleotide probe microarrays was a useful technique for paternity testing and individual identification. Combined with the 28 SNPs loci distributed on HLA-DRB1 and ABO genes, the combination discrimination power (CDP) was 0.9999999999999910. The matching probability was 9.02 x 10(-15). The average exclusion probabilities in duos and in trios were 0.9894 and 0.9992, respectively. It may be concluded that the 59 SNPs loci yield the same power in forensic identification as CODIS STRs currently used.

[Developing of a new multicolor-fluorescent labeled STR amplification kit].

OBJECTIVE: To develop a PCR-based STR system for genotyping of 18 loci (Amelogenin, D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D16S539, TH01, TPOX, CSF1PO, D7S820, D2S1338, D19S433, D12S391 and D19S253). METHODS: By using primers labeled with four color fluorescent (FAM, HEX, TAMRA and ROX), two multiplex amplification reaction systems were developed to genotype Amelogenin and 17 STR loci. RESULTS: Amelogenin and these 17 STR loci were genotyped successfully in different kinds of biological samples by the kit. CONCLUSION: The STR amplification kit developed in our study gives a new approach to genotype these 18 loci in a efficient, steady and reliable way.