Application Progress of Massively Parallel Sequencing Technology in STR Genetic Marker Detection.

In recent years, more and more forensic genetics laboratories have begun to apply massively parallel sequencing (MPS) technology, that is, next-generation sequencing (NGS) technology, to detect common forensic genetic markers, including short tandem repeat (STR), single nucleotide polymorphism (SNP), the control region or whole genome of mitochondrial DNA (mtDNA), as well as messenger RNA (mRNA), etc., for forensic practice, such as individual identification, kinship analysis, ancestry inference and body fluid identification. As the most widely used genetic marker in forensic genetics, STR is currently mainly detected by capillary electrophoresis (CE) platform. Compared with CE platform, MPS technology has the advantages of simultaneous detection of a large number of genetic markers, massively parallel detection of samples, the polymorphism of sequence detected by NGS makes STR have the advantages of higher resolution and system efficiency. However, MPS technology is expensive, there is no uniform standard so far, and there are problems such as how to integrate MPS-STR data with the existing CE-STR database. This review summarizes the current status of the application of MPS technology in the detection of STR genetic markers in forensic genetics, puts forward the main problems that need to be solved urgently, and prospects the application prospect of this technology in forensic genetics.

Genetic Polymorphism of 16 X-STR Loci in Xinjiang Uygur Population.

OBJECTIVES: To study the genetic polymorphism and population genetic parameters of 16 X-STR loci in Xinjiang Uygur population. METHODS: The Goldeneye® DNA identification system 17X was used to amplify 16 X-STR loci in 502 unrelated individuals (251 females and 251 males). The amplified products were detected by 3130xl genetic analyzer. Allele frequencies and population genetic parameters were analyzed statistically. The genetic distances between Uygur and other 8 populations were calculated. Multidimensional scaling and phylogenetic tree were constructed based on genetic distance. RESULTS: In the 16 X-STR loci, a total of 67 alleles were detected in 502 Xinjiang Uygur unrelated individuals. The allele frequencies ranged from 0.001 3 to 0.572 4. PIC ranged from 0.568 8 to 0.855 3. The cumulative discrimination power in females and males were 0.999 999 999 999 999 and 0.999 999 999 743 071, respectively. The cumulative mean paternity exclusion chance in trios and in duos were 0.999 999 997 791 859 and 0.999 998 989 000 730, respectively. The genetic distance between Uygur population and Kazakh population was closer, and the genetic distance between Uygur and Han population was farther. CONCLUSIONS: The 16 X-STR loci are highly polymorphic and suitable for identification in Uygur population, which can provide a powerful supplement for the study of individual identification, paternity identification and population genetics.

Forensic Application of ForenSeqTM DNA Signature Prep Kit in Zhengjiang She Ethnic Group.

OBJECTIVES: To evaluate the ability of the ForenSeqTM DNA Signature Prep kit (ForenSeq kit) in analyzing the sequence information of STRs in Zhejiang She ethnic group and its forensic application efficacy. METHODS: A total of 50 Zhejiang She ethnic group samples were sequenced with the ForenSeq kit on the MiSeq FGx platform. The data was analyzed using ForenSeqTM universal analysis software to obtain the motif structure and flank regions of the 58 STRs, then compared with PCR-CE typing results to test the consistency. At last, the allele frequency and population genetic parameters were calculated. RESULTS: A total of 448 sequence polymorphic alleles were detected in 50 samples of Zhejiang She ethnic group. Compared with fragment length polymorphism detected by PCR-CE, 82 alleles were increased by MPS detection based on ForenSeq kit, and 7 SNPs variation were detected in the flanking regions of 6 loci. The 22 male individuals were genotyped, and total 19 haplotypes were detected in 24 Y chromosome STRs of these 22 males. The cumulative discrimination power of the 27 autosomal STRs was 1-8.87×10-30, the cumulative probability of exclusion of duo-testing was 0.999 999 962 640 657, the cumulative probability of exclusion of trios-testing was 0.999 999 999 999 633. CONCLUSIONS: Based on MPS typing technology, using the ForenSeq kit greatly improves the detection efficiency. In addition, the 58 STRs have good genetic polymorphisms in Zhejiang She ethnic group, which are suitable for individual identification and paternity identification in forensic application.

Population Pharmacokinetics and Dosage Optimization of Linezolid in Patients with Liver Dysfunction.

Linezolid is the first synthetic oxazolidone agent to treat infections caused by Gram-positive pathogens. Infected patients with liver dysfunction (LD) are more likely to suffer from adverse reactions, such as thrombocytopenia, when standard-dose linezolid is used than patients with LD who did not use linezolid. Currently, pharmacokinetics data of linezolid in patients with LD are limited. This study aimed to characterize pharmacokinetics parameters of linezolid in patients with LD, identify the factors influencing the pharmacokinetics, and propose an optimal dosage regimen. We conducted a prospective study and established a population pharmacokinetics model with the Phoenix NLME software. The final model was evaluated by goodness-of-fit plots, bootstrap analysis, and prediction corrected-visual predictive check. A total of 163 concentration samples from 45 patients with LD were adequately described by a one-compartment model with first-order elimination along with prothrombin activity (PTA) and creatinine clearance as significant covariates. Linezolid clearance (CL) was 2.68 liters/h (95% confidence interval [CI], 2.34 to 3.03 liters/h); the volume of distribution (V) was 58.34 liters (95% CI, 48.00 to 68.68 liters). Model-based simulation indicated that the conventional dose was at risk for overexposure in patients with LD or severe renal dysfunction; reduced dosage (300 mg/12 h) would be appropriate to achieve safe (minimum steady-state concentration [Cmin,ss] at 2 to 8 µg/ml) and effective targets (the ratio of area under the concentration-time curve from 0 to 24 h [AUC0-24] at steady state to MIC, 80 to 100). In addition, for patients with severe LD (PTA, ≤20%), the dosage (400 mg/24 h) was sufficient at an MIC of ≤2 µg/ml. This study recommended therapeutic drug monitoring for patients with LD. (This study has been registered in the Chinese Clinical Trial Registry under no. ChiCTR1900022118.).

Long Noncoding RNA XR007793 Regulates Proliferation and Migration of Vascular Smooth Muscle Cell via Suppressing miR-23b.

BACKGROUND Long noncoding RNAs (lncRNAs) were identified as potential regulatory factor in vascular disease. However, the role of XR007793 in the regulation of neointima formation after vascular injury remains largely unknown. MATERIAL AND METHODS LncRNA expression levels were detected using real-time polymerase chain reaction (RT-PCR). In vivo and in vitro assay were performed in Sprague-Dawley rats and VSMCs. Cell Counting Kit-8 (CCK-8) assay, Transwell assay, and scratch wound healing assay were performed to detect cell proliferation and migration. Western blotting was used to detect protein expression. RESULTS The results of qRT-PCR indicated that XR007793 expression was significantly increased in the injured carotid artery of Sprague-Dawley rats and platelet-derived growth factor-BB induced rat aortic smooth muscle cells. Knockdown of XR007793 repressed the proliferation and migration of VSMC in vitro. The expression level of miR-23b was reduced in mouse carotid injured tissues and cell line. Bioinformatics analysis and luciferase reporter assay revealed that XR007793 directly bonds to miR-23b. Pearson correlation analysis showed that XR007793a and miR-23b were negatively correlated in carotid samples. Furthermore, bioinformatics analysis and luciferase assay indicated that miR-23b targeted the Forkhead box O 4 (FOXO4) 3'-UTR to inhibit FOXO4 expression. After transfecting miR-23b inhibitor, the expression both of XR007793 and FOXO4 was increased. The effects on expression were reversed after transfected with miR-23b mimics. Rescue experiments results indicated that miR-23b inhibitor reduced the expression of VSMC marker and promoted proliferation and migration of VSMC. CONCLUSIONS This study shows that XR007793 aggravates the loss of function of VSMCs by negatively regulating miR-23b. It does so by targeting FOXO4, which could serve as a novel therapeutic target in post-angioplasty restenosis.

[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.

Progress of DNA-based Methods for Species Identification.

Species identification of biological samples is widely used in such fields as forensic science and food industry. A variety of accurate and reliable methods have been developed in recent years. The current review shows common target genes and screening criteria suitable for species identification, and described various DNA-based molecular biology methods about species identification. Additionally, it discusses the future development of species identification combined with real-time PCR and sequencing technologies.

[Development of an 18 X-InDel multiplex PCR system].

OBJECTIVE: To investigate Insertion/Deletion (InDel) polymorphism on the X chromosome and to screen 18 InDel loci for the Chinese Han population as a forensic DNA typing system auxiliary. METHODS: Eighteen X-InDel markers were selected using the Human Genome Browser and dbSNP database. Multiplex PCR primer pairs of selected X-InDel markers were designed using Primer 3 software and divided into 3 groups according to the amplified fragment length, labeled by FAM, HEX and TAMRA fluorescence dye, respectively. The population genetics research and comparative analysis of Chinese Han nationality and 4 main minorities, the Hui, Wei, Mongol, and Tibetan nationalities, were investigated with the system. RESULTS: A new multiplex genotyping system, named InDel X-18PLEX, was successfully developed and validated, consisted of 18 X-InDel markers on the X chromosome and 1 Amelogenin gender marker. No deviation from Hardy-Weinberg equilibrium expectations was detected in the distribution of genotypes in the 5 investigated ethnic groups. However, there was significant difference between their distributions. From the investigation of Han nationality, high female (0.9999994) and male (0.999 88) overall discrimination power values were obtained, as well as high overall mean exclusion chance values in trios (0.999 992) and in duos (0.99). CONCLUSION: InDel X-18PLEX meets the requirements as a forensic DNA complementary kit, providing effective supplementary analytical tools for difficult cases.

[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.

[Forensic application of 30 InDel loci in Han and She nationalities of Eastern China].

OBJECTIVE: To evaluate the forensic application value of 30 insertion/deletion (InDel) loci included in Investigator DIPplex Kit in Han and She nationalities of Eastern China. METHODS: A total of 565 unrelated individuals in Han nationality and 119 ones in She nationality of Eastern China were investigated using Investigator DIPplex Kit. Allele frequencies, population genetics parameters of the 30 InDel loci were statistically calculated. RESULTS: In Han nationality, the mean Ho was 0.413 3, the mean DP was 0.551 1, the mean PIC was 0.320 0. And in She nationality, the mean Ho was 0.389 6, the mean DP was 0.543 3, the mean PIC was 0.310 0. No deviation from Hardy-Weinberg equilibrium was observed in Han and She nationalities (P > 0.05). CONCLUSION: The 30 loci in Investigator DIPplex Kit show good genetic diversity in Han and She nationalities, and could be used as a supplemental tool for some special paternity cases.

Effects of intensive psychological intervention on treatment compliance, psychological status, and quality of life of patients with epilepsy.

BACKGROUND: Epilepsy is a nervous system disease characterized by recurrent attacks, a long disease course, and an unfavorable prognosis. It is associated with an enduring therapeutic process, and finding a cure has been difficult. Patients with epilepsy are predisposed to adverse moods, such as resistance, anxiety, nervousness, and anxiety, which compromise treatment compliance and overall efficacy. AIM: To explored the influence of intensive psychological intervention on treatment compliance, psychological status, and quality of life (QOL) of patients with epilepsy. METHODS: The clinical data of 105 patients with epilepsy admitted between December 2019 and July 2023 were retrospectively analyzed, including those of 50 patients who underwent routine intervention (control group) and 55 who underwent intensive psychological intervention (research group). Treatment compliance, psychological status based on the Self-Rating Anxiety Scale (SAS) and Depression Scale Self-Rating Depression Scale (SDS) scores, hope level assessed using the Herth Hope Scale (HHS), psychological resilience evaluated using the Psychological Resilience Scale, and QOL determined using the QOL in Epilepsy-31 Inventory (QOLIE-31) were comparatively analyzed. RESULTS: Treatment compliance in the research group was 85.5%, which is significantly better than the 68.0% of the control group. No notable intergroup differences in preinterventional SAS and SDS scores were identified (P > 0.05); however, after the intervention, the SAS and SDS scores decreased significantly in the two groups, especially in the research group (P < 0.05). The two groups also exhibited no significant differences in preinterventional HHS, Connor-Davidson Resilience Scale (CD-RISC), and QOLIE-31 scores (P > 0.05). After 6 months of intervention, the research group showed evidently higher HHS, CD-RISC, tenacity, optimism, strength, and QOLIE-31 scores (P < 0.05). CONCLUSION: Intensive psychological intervention enhances treatment compliance, psychological status, and QOL of patients with epilepsy.

Messenger RNA profiling for forensic body fluid identification: research and applications.

Identifying the origin of body fluids left at a crime scene can give a significant insight into crime scene reconstruction by supporting a link between sample donors and actual criminal acts. However, the conventional body fluid identification methods are prone to various limitations, such as time consumption, intensive labor, nonparallel manner, varying degrees of sensitivity and limited specificity. Recently, the analysis of cell-specific messenger RNA expression (mRNA profiling) has been proposed to supplant conventional methods for body fluid identification. Since 2011, the collaborative exercises have been organized by the European DNA Profiling Group (EDNAP) in order to evaluate the robustness and reproducibility of mRNA profiling for body fluid identification. The major advantages of mRNA profiling, compared to the conventional methods, include higher sensitivity, greater specificity, the ability of detecting several body fluids in one multiplex reaction, and compatibility with current DNA extraction and analysis procedure. In the current review, we provided an overview of the present knowledge and detection methodologies of mRNA profiling for forensic body fluid identification and discussed its possible practical application to forensic casework.

[Progress in InDel as a new generation of genetic marker].

As forensic DNA typing experienced three generations of genetic marker researching stage, short tandem repeat (STR) has been widely used in forensic identification as a mature tool. Further exploration of the human genome led to the discovery of polymorphism markers of single nucleotide polymorphism (SNP) and Insertion/Deletion (InDel). InDel, which combines the desirable characteristics of previous genetic markers as a new type of genetic marker, has got extensive concern in fields like medical molecular biology and forensic biology. This paper generally reviews the history of research and the corresponding results of InDel along the line of time axis as well as the different aims of these research focusing on the progress in the multiple amplification system with several InDel as the genetic marker (autosomal or X chromosome) in forensic biology and anthropology. Finally, the direction of research in this field and the problems to be solved have been put forward.

Mitogenome evidence shows two radiation events and dispersals of matrilineal ancestry from northern coastal China to the Americas and Japan.

Although it is widely recognized that the ancestors of Native Americans (NAs) primarily came from Siberia, the link between mitochondrial DNA (mtDNA) lineage D4h3a (typical of NAs) and D4h3b (found so far only in East China and Thailand) raises the possibility that the ancestral sources for early NAs were more variegated than hypothesized. Here, we analyze 216 contemporary (including 106 newly sequenced) D4h mitogenomes and 39 previously reported ancient D4h data. The results reveal two radiation events of D4h in northern coastal China, one during the Last Glacial Maximum and the other within the last deglaciation, which facilitated the dispersals of D4h sub-branches to different areas including the Americas and the Japanese archipelago. The coastal distributions of the NA (D4h3a) and Japanese lineages (D4h1a and D4h2), in combination with the Paleolithic archaeological similarities among Northern China, the Americas, and Japan, lend support to the coastal dispersal scenario of early NAs.

A rare cause of goiter: Langerhans cell histiocytosis of the thyroid.

Goiter is a very common clinical problem; however, Langerhans cell histiocytosis (LCH) with thyroid involvement that presents as a goiter is very rare. In this article, we report one case of thyroid LCH. An 18-year-old male patient presented with goiter, polyuria, polydipsia, and lymphadenectasis of the neck, and LCH was confirmed by a lymph node biopsy and pathological investigation. Without a thyroidectomy, the goiter shrank after nine cycles of chemotherapy. In addition, we summarize the reported thyroid LCH cases in the literature from the last 10 years. LCH usually involves other organs, such as the lungs, bones, skin, pituitary gland, and lymph nodes. Thyroid LCH is more common in adults than in children, and it may coexist with a thyroid carcinoma. Without any unique thyroid manifestations, either clinically or by imaging, it is difficult to distinguish thyroid LCH from other thyroid diseases. Pathology is the gold standard for the diagnosis of LCH. A fine needle aspiration biopsy (FNAB) may help to diagnosis LCH, although sometimes it leads to misdiagnosis. Chemotherapy is recommended for multi-system LCH. Younger patients with widespread disease or who are non-responsive to chemotherapy have poor outcomes.

[Forensic application of investigator HDplex kit in Han nationality of Eastern China].

OBJECTIVE: To investigate the genetic data of 12 autosomal STR loci included in Investigator HDplex kit and to evaluate its forensic application in Han nationality of Eastern China. METHODS: A total of 484 unrelated healthy individuals in Han nationality of Eastern China were investigated with Investigator HDplex kit. Allele frequencies, population genetics parameters and linkage disequilibrium information of the 12 autosomal STR loci were statistically analyzed. RESULTS: No deviations from Hardy-Weinberg equilibrium were detected and all loci were independent form each other within the studied 484 unrelated healthy individuals. DP values of the 12 autosomal STR loci were all above 0.8, and CDP was 0.999 999 999 92. The cumulative probability of paternity exclusion in duo and in trio were 0.999 82 and 0.999 998 6, respectively. CONCLUSION: Investigator HDplex kit with 12 highly polymorphic STR loci in Han nationality of Eastern China could be used effectively for forensic DNA genotyping.

[Typing and polymorphism analysis of 16 STR loci on X chromosome].

OBJECTIVE: To develop a PCR-based X-STR kit for typing of 16 X-STR loci and investigate the polymorphisms of the X-STR markers. METHODS: Sixteen STR loci (GATA 165B12, DXS101, GATA 172D05, HPRTB, DXS981, DXS8378, DXS6795, GATA 31E08, DXS6809, DXS6803, DXS9902, DXS6807, DXS7423, DXS7133, DXS6810 and DXS7132) located on X chromosome were selected. The primers for multiplex PCR were designed by Primer Premier 5.0 software and labeled by four fluorescences (FAM, HEX, TAMRA and ROX). The developed multiplex PCR system was used for investigating the polymorphisms of the X-STR markers in Han populations. RESULTS: The 16-plex amplification system named IDtyper X-16 was successfully developed and validated. Among the 16 X-STR loci, DXS7133 and DXS7423 were found to be moderately polymorphic and the other 14 X-STR markers were highly polymorphic (P1C > 0.5, H > 0.5). The cumulative discrimination power in females and in males were 0.999 999 999 999 97 and 0.999 999 993 respectively in Han population. The combined power of exclusion in trios and in duos were 0.999 999 93 and 0.999990, respectively. CONCLUSION: The IDtyper X-16 kit is highly valuable in forensic science and is suitable for paternity testing in disputed cases.

[Algorithms of likelihood ratio for discriminating full sibling from half sibling].

OBJECTIVE: To derive the formulae for likelihood ratio calculation in discriminating full sibling from half sibling with single-parent participation or without parent participation. METHODS: Null hypothesis and alternative hypothesis were established for discriminating full sibling from half sibling in two circumstances: two children with single-parent and without parent participation. Conditional probabilities of the genetic evidentiary under null and alternative hypotheses were calculated according to the Bayesian theory. The likelihood ratios were established with the conditional probability under alternative hypothesis division that under null hypothesis, followed with simplification. All the formulae were validated in a real case. RESULTS: While mother or fathers' genetic information available in differentiating full sibling from half sibling, 14 different genotype combinations could be shared by the two detected children at a given locus and the likelihood ratio could be calculated with 5 different formulae respectively. While both parents' genetic information unavailable, 11 different genotype combinations could be shared and the likelihood ratio could be calculated with 7 different formulae respectively. It was validated in a real case that the power of the likelihood ratio method developed for discriminating full sibling from half sibling with single-parent participation was higher than that of the ratio of full sibling index over half sibling index. CONCLUSION: The formulae of likelihood ratio developed are useful for discriminating full sibling from half sibling with single-parent participation or without parent participation.

[Genetic polymorphisms of 21 non-CODIS STR loci].

OBJECTIVE: To investigate genetic polymorphisms of 21 non-CODIS STR loci in Han population from the east of China and to explore their forensic application value. METHODS: Twenty-one non-CODIS STR loci, were amplified with AGCU 21+1 STR kit and DNA samples were obtained from 225 unrelated individuals of the Han population from the east of China. The PCR products were analyzed with 3130 Genetic Analyzer and genotyped with GeneMapper ID v3.2 software. The genetic data were statistically analyzed with PowerStats v12.xls and Cervus 2.0 software. RESULTS: The distributions of 21 non-CODIS STR loci satisfied the Hardy-Weinberg equilibration. The heterozygosity (H) distributions were 0.596-0.804, the discrimination power (DP) were 0.764-0.948, the probability of exclusion of duo-testing (PEduo) were 0.176-0.492, the probability of exclusion of trios-testing (PEtrio) were 0.334-0.663, and the polymorphic information content (PIC) were 0.522-0.807. The cumulative probability of exclusion (CPE) of duo-testing was 0.999707, the CPE of trios-testing was 0.9999994, and the cumulated discrimination power (CDP) was 0.99999999999999999994. CONCLUSION: Twenty-one non-CODIS STR loci are highly polymorphic. They can be effectively used in personal identification and paternity testing in trios cases. They can also be used as supplement in the difficult cases of diad paternity testing.

[A primary study of criterion for source identification of gastrointestinal tumor sample with Identifiler multiplex system].

OBJECTIVE: To investigate the criterion for source identification of gastrointestinal tumor based on the number of identical allele (IAn) and the number of matched STR locus with 2 identical alleles (A2) in Identifiler system. METHODS: One hundred and five pairs of gastrointestinal tumor samples and homologous normal samples (TN group) were genotyped with Identifiler system. The numbers of STR locus with genotypic alteration (STRGA) in each tumor were determined by comparing the genotype of the matched STR loci in each pair of samples. According to the limited distribution of IAn and A2, 16 different values of IAn was substituted into the published discriminant functions to obtain the cut-off values of IAn and A2 for source identification of tumor sample. Indices including sensitivity (SEN), specificity (SPE), accuracy (AC), positive predictive value (PPV) and negative predictive value (NPV) for distinguishing tumor from an unrelated individual or a full sibling of the patient were calculated. Concordance of the identification results based on the determined criteria and the definite facts were statistically tested with Kappa index. RESULTS: The total frequency of STRGA was 5.46%. There were 31.43% of the 105 tumor samples carried at least one STR locus with STRGA mutation. According to the Fisher discrimination rules, criteria I (IAn>or=23 and A2>or=8) and criteriall (IAn>or=26 and A2>or=11) meet the requirements of distinguishing tumor sample from an unrelated individual or a full sibling of the patient with tumor, respectively. SEN=0.971 0, PPV=1.000 0, PPV=0.891 9 and Kappa=0.923 5, when the criteria were used to determine the specified relatives. CONCLUSION: Criteria I and criteria II were powerful for distinguishing tumor sample from an unrelated individual or a full sibling of the patient with tumor, respectively, when the Identifiler system was adopted for source identification of gastrointestinal tumor sample.