Zhenmin Zhao

Genetic polymorphism of 17 STR loci for forensic use in Chinese population from Shanghai in East China

Allele frequencies for 17 STR loci found in Identifier kit and PowerPlex16 Monoplex System were determined in a sample of 1000 unrelated individuals living in Shanghai in East China. The values of observed heterozygosity (Ho), power of discrimination (PD), probability of paternity exclusion (PE) and polymorphism information content (PIC) were calculated. All loci were in accordance with Hardy-Weinberg equilibrium (p<0.05). The obtained frequency distributions were compared with other previously reported population data.

Genetic polymorphisms in 12 autosomal STRs in a Shanghai Han population from China

In this study, a total of 484 unrelated healthy individuals and 359 two‐generation families in the Han population in Shanghai, China were successfully analyzed with the Investigator HDplex Kit (Qiagen, Hilden, Germany). Hardy–Weinberg equilibrium tests demonstrated no significant deviation from expected values (p > 0.05) for the 12 autosomal STRs included in this kit. A total of 173 alleles were detected in 12 autosomal STR loci; the largest number of alleles (32) was detected for the SE33 locus. The combined power of discrimination was 0.99999999992. The combined mean exclusion chance in duo cases was 0.99982, whereas the combined mean exclusion chance in trio cases was 0.9999986. The average mutation rate across all loci was 0.0023 (95% confidence intervals: 0.0013–0.0039). These results suggest that the 12 autosomal STR loci can provide highly informative polymorphic data for paternity testing and forensic identification in the Han population in Shanghai, China.

Forensic investigation of 23 autosomal STRs and application in Han and Mongolia ethnic groups

ABSTRACT A forensic validation study of the Early Access Huaxia™ Platinum Polymerase Chain Reaction (PCR) kit was completed to document the performance capabilities and limitations. The genotyping of DNA samples was consistent across a large range of template DNA concentrations, with complete profiles obtained at 0.125 ng; however, no more than 2 mm × 1.2 mm punches of samples would be recommended for direct amplification. The size precision and accuracy test revealed the genotyping ability; while consistent results were obtained when comparing the kit with other commercially available systems. In addition, the whole PCR amplification can finish within approximately 45 min, making the system suitable for fast-detection. However, only partial profiles may be obtained with challenging samples, including DNA stored on Foam-Tipped Applicators (FTA) cards or some case samples. For the forensic application in ethnic groups, a total of 282 and 229 alleles were obtained in Han and Mongolia, respectively. Since the 23 short tandem repeats were independent from each other, the cumulative power of exclusion in duos was 0.999 999 157 188 and the cumulative power of exclusion in trios was 0.999 999 999 859 in the Han group while the cumulative power of exclusion in duos (CPEduo) was 0.999 998 848 26 and cumulative power of exclusion in trios (CPEtrio) was 0.999 999 999 79 in the Mongolia group. And good internal consistency was found between the two investigated groups and the Sichuan Han, Hui, Tibetan and Uygur according to available reference data.

A case of false mother included with 46 autosomal STR markers

BackgroundFor solving a maternity case, 19 autosomal short tandem repeats (STRs) were amplified using the AmpFℓSTR® SinofilerTM kit and PowerPlex® 16 System. Additional 27 autosomal STR loci were analyzed using two domestic kits AGCU 21+1 and STRtyper-10G. The combined maternity index (CMI) was calculated to be 3.3 × 1013, but the putative mother denied that she had given birth to the child. In order to reach an accurate conclusion, further testing of 20 X-chromosomal short tandem repeats (X-STRs), 40 single nucleotide polymorphism (SNP) loci, and mitochondrial DNA (mtDNA) was carried out.FindingsThe putative mother and the boy shared at least one allele at all 46 tested autosomal STR loci. But, according to the profile data of 20 X-STR and 40 SNP markers, different genotypes at 13 X-STR loci and five SNP loci excluded maternity. Mitochondrial profiles also clearly excluded the mother as a parent of the son because they have multiple differences. It was finally found that the putative mother is the sister of the biological father.ConclusionsDifferent kinds of genetic markers needfully supplement the use of autosomal STR loci in case where the putative parent is suspected to be related to the true parent.