scholarly journals A Novel SNP-STR System Based on a Capillary Electrophoresis Platform

2021 ◽  
Vol 12 ◽  
Author(s):  
Hui Jian ◽  
Li Wang ◽  
Meili Lv ◽  
Yu Tan ◽  
Ranran Zhang ◽  
...  

Various compound markers encompassing two or more variants within a small region can be regarded as generalized microhaplotypes. Many of these markers have been investigated for various forensic purposes, such as individual identification, deconvolution of DNA mixtures, or forensic ancestry inference. SNP-STR is a compound biomarker composed of a single nucleotide polymorphism (SNP) and a closely linked short tandem repeat polymorphism (STR), and possess the advantages of both SNPs and STRs. In addition, in conjunction with a polymerase chain reaction (PCR) technique based on the amplification refractory mutation system (ARMS), SNP-STRs can be used for forensic unbalanced DNA mixture analysis based on capillary electrophoresis (CE), which is the most commonly used platform in worldwide forensic laboratories. Our previous research reported 11 SNP-STRs, but few of them are derived from the commonly used STR loci, for which existing STR databases can be used as a reference. For maximum compatibility with existing DNA databases, in this study, we screened 18 SNP-STR loci, of which 14 were derived from the expanded CODIS core loci set. Stable and sensitive SNP-STR multiplex PCR panels based on the CE platform were established. Assays on simulated two-person DNA mixtures showed that all allele-specific primers could detect minor DNA components in 1:500 mixtures. Population data based on 113 unrelated Chengdu Han individuals were investigated. A Bayesian framework was developed for the likelihood ratio (LR) evaluation of SNP-STR profiling results obtained from two-person mixtures. Furthermore, we report on the first use of SNP-STRs in casework to show the advantages and limitations for use in practice. Compared to 2.86 × 103 for autosomal STR kits, the combined LR reached 7.14 × 107 using the SNP-STR method in this casework example.

2001 ◽  
Vol 47 (4) ◽  
pp. 667-672 ◽  
Author(s):  
Rossa W K Chiu ◽  
Michael F Murphy ◽  
Carrie Fidler ◽  
Benny C Y Zee ◽  
James S Wainscoat ◽  
...  

Abstract Background: Rh isoimmunization and hemolytic disease of the newborn still occur despite the availability of Rh immunoglobulin. For the prenatal investigation of sensitized RhD-negative pregnant women, determination of the zygosity of the RhD-positive father has important implications. The currently available molecular methods for RhD zygosity assessment, in general, are technically demanding and labor-intensive. Therefore, at present, rhesus genotype assessment is most commonly inferred from results of serological tests. The recent elucidation of the genetic structure of the prevalent RHD deletion in Caucasians, as well as the development of real-time PCR, allowed us to explore two new approaches for the molecular determination of RhD zygosity. Methods: Two methods for RhD zygosity determination were developed. The first was based on the double Amplification Refractory Mutation System (double ARMS). The second was based on multiplex real-time quantitative PCR. For the double ARMS assay, allele-specific primers were designed to directly amplify the most prevalent RHD deletion found in RhD-negative individuals in the Caucasian population. The multiplex real-time quantitative PCR assay, on the other hand, involved coamplification and quantification of RHD-specific sequences in relation to a reference gene, albumin, in a single PCR reaction. A ratio, ΔCt, based on the threshold cycle, was then determined and reflects the RHD gene dosage. Results: The allele-specific primers of the double ARMS assay reliably amplified the RHD-deleted allele and therefore accurately distinguished homozygous from heterozygous RhD-positive samples. The results were in complete concordance with serological testing. For the multiplex real-time quantitative PCR assay, the ΔCt values clearly segregated into two distinct populations according to the RHD gene dosage, with mean values of 1.70 (SD, 0.17) and 2.62 (SD, 0.29) for the homozygous and heterozygous samples, respectively (P <0.001, t-test). The results were in complete concordance with the results of serological testing as well as with the double ARMS assay. Conclusion: Double ARMS and real-time quantitative PCR are alternative robust assays for the determination of RhD zygosity.


2016 ◽  
Vol 131 (3) ◽  
pp. 651-652 ◽  
Author(s):  
Feng Song ◽  
Jienan Li ◽  
Lushun Zhang ◽  
Haibo Luo

2004 ◽  
Vol 144 (1) ◽  
pp. 69-71 ◽  
Author(s):  
Z Szczerkowska ◽  
E Kapińska ◽  
J Wysocka ◽  
L Cybulska

2016 ◽  
Vol 117 (2-3) ◽  
pp. 90-97 ◽  
Author(s):  
Hamid Reza Kouhpayeh ◽  
Mohsen Taheri ◽  
Mana Baziboroon ◽  
Mohammad Naderi ◽  
Gholamreza Bahari ◽  
...  

Cysteine-cysteine chemokine ligand 5 (CCL5) with immunoregulatory and inflammatory activities has an important role in granuloma formations that activates and stimulates T-cells and macrophages. Cysteine-cysteine chemokine receptor 5 (CCR5) is a chemokine receptor, which is important for migration of immune cells to site of infection. In the present study we investigated the possible association between CCL5 –403G/A (rs2107538), CCL5 –28C/G (rs2280788) and CCR5 Δ32 polymorphisms and pulmonary tuberculosis (PTB) in an Iranian population. This case-control study was performed on 160 patients with pulmonary tuberculosis and 160 unrelated healthy subjects. The CCL5 –403G/A, CCL5 –28C/G and CCR5 Δ32 polymorphisms were genotyped by allele-specific polymerase chain reaction (AS-PCR), tetra amplification refractory mutation system polymerase chain reaction (T-ARMS PCR) and PCR, respectively. Our results showed that GA as well as GA+AA genotypes of CCL5 –403G/A (rs2107538) increased the risk of PTB in comparison with GG genotype (OR=1.70, 95% CI=1.03–2.81, P=0.038 and OR=1.64, 95% CI=1.00–2.68, P=0.049, respectively). No significant association was found between CCL5 –28C/G as well as CCR5 Δ32 polymorphism and PTB risk. In conclusion, our findings proposed that CCL5 –403G>A polymorphism may be a risk factor for susceptibility to PTB in our population. Larger sample sizes with different ethnicities are required to validate our findings.


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