Application of Familial Y-STR Haplotype Mismatch Tolerance in Genealogy Inference / 法医学杂志

OBJECTIVES@#To provide a guideline for genealogy inference and family lineage investigation through a study of the mismatch tolerance distribution of Y-STR loci in Chinese Han male lineage.@*METHODS@#Three Han lineages with clear genetic relationships were selected. YFiler Platinum PCR amplification Kit was used to obtain the typing data of 35 Y-STR loci in male samples. The variation of Y-STR haplotypes in generation inheritance and the mismatch tolerance at 1-7 kinship levels were statistically analyzed.@*RESULTS@#Mutations in Y-STR were family-specific with different mutation loci and numbers of mutation in different lineages. Among all the mutations, 66.03% were observed on rapidly and fast mutating loci. At 1-7 kinship levels, the number of mismatch tolerance ranged from 0 to 5 on all 35 Y-STR loci, with a maximum step size of 6. On medium and slow mutant loci, the number of mismatch tolerance ranged from 0 to 2, with a maximum step size of 3; on rapidly and fast mutant loci, the number of mismatch tolerance ranged from 0 to 3, with a maximum step size of 6.@*CONCLUSIONS@#Combined use of SNP genealogy inference and Y-STR lineage investigation, both 0 and multiple mismatch tolerance need to be considered. Family lineage with 0-3 mismatch tolerance on all 35 Y-STR loci and 0-1 mismatch tolerance on medium and slow loci can be prioritized for screening. When the number of mismatch tolerance is eligible, family lineages with long steps should be carefully excluded. Meanwhile, adding fast mutant loci should also be handled with caution.

Identification Strategy of Biological Half Sibling Relationship / 法医学杂志

OBJECTIVES@#To compare the application value of the likelihood ratio (LR) method and identity by state (IBS) method in the identification involving half sibling relationships, and to provide a reference for the setting of relevant standards for identification of half sibling relationship.@*METHODS@#(1) Based on the same genetic marker combinations, the reliability of computer simulation method was verified by comparing the distributions of cumulated identity by state score (CIBS) and combined full sibling index in actual cases with the distributions in simulated cases. (2) In different numbers of three genetic marker combinations, the simulation of full sibling, half sibling and unrelated individual pairs, each 1 million pairs, was obtained; the CIBS, as well as the corresponding types of cumulative LR parameters, were calculated. (3) The application value of LR method was compared with that of IBS method, by comparing the best system efficiency provided by LR method and IBS method when genetic markers in different amounts and of different types and accuracy were applied to distinguish the above three relational individual pairs. (4) According to the existing simulation data, the minimum number of genetic markers required to distinguish half siblings from the other two relationships using different types of genetic markers was estimated by curve fitting.@*RESULTS@#(1) After the rank sum test, under the premise that the real relationship and the genetic marker combination tested were the same, there was no significant difference between the simulation method and the results obtained in the actual case. (2) In most cases, under the same conditions, the system effectiveness obtained by LR method was greater than that by IBS method. (3) According to the existing data, the number of genetic markers required for full-half siblings and half sibling identification could be obtained by curve fitting when the system effectiveness reached 0.95 or 0.99.@*CONCLUSIONS@#When distinguishing half sibling from full sibling pairs or unrelated pairs, it is recommended to give preference to the LR method, and estimate the required number of markers according to the identification types and the population data, to ensure the identification effect.

Evaluation of Detection Efficiency for Trio Full Sibling Testing / 法医学杂志

OBJECTIVES@#To study the detection efficiency of trio full sibling with another known full sibling reference added under different number of autosomal STR typing systems.@*METHODS@#Based on 43 detection systems consisting of 13 to 55 representative autosomal STR loci, 10 000 true families (full sibling group) and 10 000 false families (unrelated individual group) were randomly simulated. The full sibling index (FSI) was calculated based on the method of family reconstruction. The cumulative sibling relationship index (CFSI) of 0.000 1 and 10 000 were used as the evaluation thresholds, and the detection efficiency parameters were calculated and compared with the identification of the duo full sibling testing.@*RESULTS@#With the increasing number of STR loci, the error rate and inability of judgement rate gradually decreased; the sensitivity, specificity, correct rate of judgment and other parameters gradually increased, and the system efficiency gradually improved. Under the same detection system, trio full sibling testing showed higher sensitivity, specificity, system efficiency and lower inability of judgement rate compared with duo full sibling testing. When the system efficiency was higher than 0.85 and inability of judgement rate was less than 0.01%, at least 20 STRs should be detected for trio full sibling testing, which was less than 29 STRs required by duo full sibling testing.@*CONCLUSIONS@#The detection efficiency of trio full sibling testing is superior to that of duo full sibling testing with the same detection system, which is an effective identification scheme for laboratories with inadequate detection systems or for materials with limited conditions.

Research Progresses of Tri-Allelic Patterns in Autosomal STR in Forensic DNA Analysis / 法医学杂志

Tri-allelic pattern in autosomal STR is a common abnormal typing phenomenon in forensic DNA analysis, which brings difficulties and uncertainties to the evaluation of the evidence weight in actual cases. This paper reviews the types, formation mechanism, occurrence frequency, genetic pattern and quantitative evaluation of evidence of the tri-allelic pattern in autosomal STR in forensic DNA analysis. This paper mainly explains the formation mechanism and genetic patterns based on different types of tri-allelic pattern. This paper also discusses the determination of tri-allelic pattern and the quantitative method of evidence evaluation in paternity testing and individual identification. This paper aims to provide references for scientific and standardized analysis of this abnormal typing phenomenon in forensic DNA analysis.

Classification of Common Relationships Based on Short Tandem Repeat Profiles Using Data Mining / 대한법의학회지

We reviewed past studies on the identification of familial relationships using 22 short tandem repeat markers. As a result, we can obtain a high discrimination power and a relatively accurate cut-off value in parent-child and full sibling relationships. However, in the case of pairs of uncle-nephew or cousin, we found a limit of low discrimination power of the likelihood ratio (LR) method. Therefore, we compare the LR ranking method and data mining techniques (e.g., logistic regression, linear discriminant analysis, diagonal linear discriminant analysis, diagonal quadratic discriminant analysis, K-nearest neighbor, classification and regression trees, support vector machines, random forest [RF], and penalized multivariate analysis) that can be applied to identify familial relationships, and provide a guideline for choosing the most appropriate model under a given situation. RF, one of the data mining techniques, was found to be more accurate than other methods. The accuracy of RF is 99.99% for parent-child, 99.44% for full siblings, 90.34% for uncle-nephew, and 79.69% for first cousins.

Genetic polymorphisms and genetic relationship of 24 autosomal STR loci in Gelao and Miao population of Guizhou / 解放军医学杂志

Objective: To investigate the genetic polymorphisms of 24 autosomal short tandem repeats (STR) loci in Gelao and Miao populations dwelled in Guizhou province, and explore the population genetic relationships and evaluate their application value on forensic medicine. Methods: The DNA samples of 732 unrelated individuals (399 Guizhou Gelao population and 333 Guizhou Miao population) were amplified using SureID® PanGlobal kit, and the PCR products were analyzed by electrophoresis through 3500XL genetic analyzer. The fragment sizes of alleles were subsequently analyzed by GeneMapper ID-X v1.5. Allele frequencies and forensic genetic parameters of 24 STR loci were statistically analyzed and compared with the available data of other populations from different races and regions. Results: For Guizhou Gelao and Miao populations, the individual discrimination power (DP) ranged from 0.7833 to 0.9909 and 0.8010 to 0.9909, respectively; the polymorphic information content (PIC) ranged from 0.5608 to 0.9385 and 0.5677 to 0.9414, respectively; the total discrimination power (TDP) were 1-7.6036 × 10-30 and 1-6.8630 × 10-30, respectively, and the cumulative probability of exclusion (CPE) were 1-1.9608 × 10-11 and 1-1.9738 × 10-14, respectively. Analysis with the matrix of Nei's DA genetic distance indicated that the genetic distance was the smallest (0.0205) between Guizhou Gelao and Hubei Han populations, while was the largest (0.0449) between Guizhou Gelao and Yunnan Miao populations; the genetic distance was minimum (0.0033) between Guizhou Miao and Hunan Han populations, while was maximal (0.0363) between Guizhou Miao and Yunnan Miao. Conclusions: The 24 STR loci are abundant in genetic polymorphism in Guizhou Gelao and Miao populations. It is of great significance to study the genetic diversity of different ethnic groups in order to understand their origin, migration and interrelationship.

Influence of uniparental disomy on the conclusion of paternity testing / 中华医学遗传学杂志

Objective@#To explore the influence of uniparental disomy (UPD) on bipartite and tripartite paternity testing.@*Methods@#Two cases of paternity testing were analyzed by multiplex amplification and capillary electrophoresis typing. Suspected UPD was verified by using single nucleotide polymorphism array (SNP array). Parental power index was calculated by using a bipartite or tripartite model.@*Results@#The two cases were found to harbor respectively three short tandem repeats on chromosome 2 and two short tandem repeats on chromosome 15. SNP array verified that both cases were of UPD. Case 1 had a parental power index of 122274987565.23 by a tripartite model, while case 2 had a parental power index of 13500.8463 by a bipartite model. Based on the technical specification, the conclusions supported a biological parent-child relationship in both cases.@*Conclusion@#UPD may lead to misjudgment of paternity testing. The possibility of UPD should be considered when certain loci which do not conform to Mendelian inheritance have aggregated to one chromosome.

Genetic polymorphisms of 19 X-STR loci for forensic application in China’s three ethnicities / 基础医学与临床

Objective To investigate the genetic data of the 19 X-STR loci in three ethnicities of China ( Han, Gelao,Miao) and to evaluate the application in forensic science.Methods The DNA samples of unrelated individ-ual in Han (n=308), Gelao (n=398), Miao (n=323) ethnicities were amplified using MicroreaderTM19X ID System kit, and the PCR products were analyzed by electrophoresis through 3500XL genetic analyzer. The fragment sizes of alleles were taken subsequently by GeneMapper? ID-X. Allele frequencies and national genetics parameters of the 19 X-STR were analyzed by statistics. The allele frequencies were compared among the three nationalities and were compared with available data of other Han ethnicities from different regions. Results After the Bonferroni correction at a 95% significance level, no significant departures from the Hardy-Weinberg equilibrium was observed. Linkage disequilibrium test showed no significant allelic association between all 19 X-STR loci after Bonferroni’s correction. The cumulative discrimination power in females and in males were greater than 0.999 999 999 99 and 0.999 999 999 94,respectively. The combined power of exclusion in trios and in duos were greater than 0.999 999 999 36 and 0.999 999 52,respectively. The p values,calculated throuth Arle-quin v3.5 software,there were significantly different as detected at loci of X-STR among the different nationalities. Conclusions This panel of X-STR is highly polymorphic in China’s three ethnicities and can be served as a supple-mentary to the current STR system for individual identification.

Diagnosis and treatment of graft-versus-host-disease after kidney transplantation: A Case Report and Literature Review / 中华器官移植杂志

Objective To investigate the diagnosis and treatment of graft-versus-host-disease (GVHD) after solid organ transplant (SOT) and the possible mechanism.Methods In this study,we retrospectively reported a rare case of GHVD after kidney transplantation and performed a literature review.This 51 year old male patient presented with over 10-day history of sporadic skin rash on postoperative day 50.Skin biopsy examination revealed GVHD.For further clear diagnosis,patient's peripheral blood was collected immediately for short tandem repeats (STR) enriched for CD3+ cells and we also performed immunofluorescent staining for patient's skin with specific HLA-A11 antibody,one of donor specific HLA sites.Meanwhile,the decreased immunosuppression was used for treatment.Results In our report,chimerism analysis by STR revealed no chimerism in patient's peripheral blood.However,immunofluorescent staining of patient's skin demonstrated abundant donor-derived lymphocytic infiltration existed.GVHD was definitely made in this case.After treatment with decreased immunosuppression and a low dose of methylprednisolone (MP),his clinical symptom was quickly alleviated.Now the patient was discharged and the renal function was normal.Conclusion Combined with literature review and our case report,we thought that chimerism analysis by STR and immunofluorescent staining by donor-specific HLA antibody were very useful for diagnosis of GVHD after SOT.Furthermore,GVHD referred to over-immunosuppression and prognosis of GVHD after kidney transplantation is usually satisfactory.

Risk analysis on duo paternity tests / 中国法医学杂志

Objective To discuss the risk in duo paternity testing. Methods 22 fictitious duo families formed by 22 pairs of unrelated individuals having one or zero inconsistent locus were selected after detected by GoldeneyeTM 20A Kit. The 22 fictitious duo families were further tested with STRtyper-10G kit and/or AGCU 21+1 STR kit until there were more than 3 inconsistent loci and the cumulative paternity index(CPI) value was less than 0.0001. According to the three excluding rules, ① number of inconsistent loci>3; ② CPI ≤ 0.0001; ③ accord with both ① and ② , using multiple STR systems, such as 19 STR loci, 26 STR loci, 39 STR loci and 46 STR loci to test and discuss whether there is difference among the excluding result of unrelated individual. Results Among those 22 fictitious duo families, using three excluding rules, None was excluded by 19 STR loci, and all was excluded by 39 STR loci. Conclusion Duo paternity tests may get a wrong result using only 19 loci system. To reduce the error risk 39 STR-loci systems would be suggested.

A study on the tendency of genetic alteration of STR loci in human lung cancer tissues / 中国癌症杂志

Background and purpose: Short tandem repeats (STR) multiplex PCR fluorescence detection technology is the most widely used DNA technology in individual identity and genetic identification. It's the most direct method to obtain accurate conclusions. However, some studies have indicated that the rate of STR mutations in tumor tissue is significantly higher than that in normal tissues or blood. This study aimed to investigate the tendency of genetic instability in 20 STR loci on autosomal and Amel loci in tumor tissue samples from lung cancer. Methods: This study, collected 75 cases of human lung cancer tissues and the adjacent normal tissues. DNA samples were extracted by tissue DNA extraction kit, amplified using MicroreaderTM 21 Direct ID System PCR amplification kit. Capillary electrophoresis was performed using API 3130 analyzer, and results were analyzed by genetic analysis software (Gene Mapper ID V3.2). Results: STR alterations were detected in 24 specimens from 75 lung cancer tissues (32%). Fifty-five alterations were detected in the frequently used 21 STR loci in total, including additional alleles 10 times, loss of heterozygosity 10 times, partial loss of heterozygosity 35 times. Partial loss of heterozygosity was the most common genetic alteration types accounting for 63.64% of the total alteration frequency. And multiple genetic alteration types could occur in the same lung cancer tissue. Among them, the highest alteration frequency occurred on D5S818 (7 times), secondly on D3S1358 and D12S391 (both 5 times), and no alterations on D2S441 and Penta E. Combining the experimental results and analysis on clinical data, this study found the statistical differences between the staging of lung cancer and the age of the patients with the STR loci alterations (P0.05). Conclusion: STR loci of the lung cancer tissue were not stable, and the alteration occurred in the aged or high malignant degree lung cancer tissue more frequently. Meanwhile, no alteration was detected on D2S441 and Penta E. In the future research the two STR loci should be verified to determine whether they can be used as the stable STR loci in such cases by increasing the sample size.

Comparison of gene frequencies of short tandem repeats loci on Y Chromosome between offenders with initiative-aggressive behavior and impulsive-aggressive behavior / 中华行为医学与脑科学杂志

Objective To explore the distributional differences of the gene frequencies of 22 short tandem repeats loci on Y Chromosome(Y?STRs) between offenders with Initiative?aggressive behavior and impulsive?aggressive behavior,and to probe into the genetic factors of initiative?aggressive behavior and im?pulsive?aggressive behavior. Methods Biological samples of 271 offenders with initiative?aggressive behav?ior and 271 offenders with impulsive?aggressive behavior were collected and PCR compound amplification was carried out with the aid of PowerPlex Y23 System. Then the PCR products were subjected to electrophoresis and gene detection with AB3500xL gene analysis system so as to calculate and compare the alleles and haplo?types of 22 Y?STRs gene frequency in the two groups. Results The distribution of allele frequency were sig?nificantly difference in locus DYS437(P=0.022) between two groups,not in the other 21 Y?STRs loci( all P>0.05) . Univarite analysis showed significant differences at allelle 14 in locus DYS437 between both groups ( initiative?aggressive behavior group:69. 37%;impulsive?aggressive behavior group:58. 67%; P=0. 009 ) . Conclusion Loci DYS437 may be associated with aggressive behavior. In the group of aggressive behavior, allelle 14 on locus DYS437 may be the susceptible factor of initiative?aggressive behavior and the resistant factor of impulsive?aggressive.

Genetic polymorphisms of 19 Y-STR loci in in the Han population in Northeast China and the cluster analysis of ethnic groups in northeast Asia region / 重庆医学

Objective To investigate the polymorphisms of the 19 Y-STR loci in the Han population in Northeast China,and analyze the genetic relationships of 15 ethnic groups in northeast Asia region,and to evaluate their forensic value and population genetic value.Methods The 19 Y-STR unrelated Han males in 200 unrelated Han males in Northeast China were amplified with the Y-filer system,and the PCR products were analyzed by the 310 Genetic Analyzer.The AMOVA analysis,cluster analysis and MDS analysis were calculated by Arelquin3.11,Mega4.1 and SPSS17.0.Results The polymorphisms of 19 Y-STR loci in the Han population in Northeast China had generally higher gene diversity value which were ranged from 0.350 9 (DYS391) to 0.971 1 (DYS385a/b),and totally 200 haplotypes were observed.The 19 Y-STR loci displayed high genetic polymorphisms in the Han population in Northeast China,indicating that these 19 loci were useful genetic markers for forensic personal identification and paternity testing.There were distinctions among 15 ethnic groups.The genetic distance between 15 ethnic groups were ranged from 0.000 9 to 0.643 2,and the conclusion of cluster analysis and MDS analysis were similar to the ethnogeny research and ethnic migration history.Conclusion The 19 Y-STR loci displayed high genetic polymorphisms in the Han population in Northeast China,and these 19 loci were useful genetic markers for forensic personal identification and paternity testing.

Haplotype and genetic relationship of 27 Y-STR loci in Han population of Chaoshan area of China / 解放军医学杂志

Objective To investigate the genetic polymorphisms of 27 Y-chromosomal short tandem repeats (Y-STR) loci included in Yfiler(R) Plus kit in Han population of Chaoshan area,and explore the population genetic relationships and evaluate its application value on forensic medicine.Methods By detecting 795 unrelated Chaoshan Han males with Yfiler(R) Plus kit,haplotype frequencies and population genetics parameters of the 27 Y-STR loci were statistically analyzed and compared with available data of other populations from different races and regions for analyzing the genetic distance and clustering relation of Chaoshan Han population.Results Seven hundred and eighty-seven different haplotypes were observed in 795 unrelated male individuals,of which 779 haplotypes were unique,and 8 haplotypes occurred twice.The haplotype diversity (HD) was 0.999975 with discriminative capacity (DC) of 98.99％.The gene diversity (GD) at the 27 Y-STR loci ranged from 0.3637(DYS391) to 0.9559(DYS385a/b).Comparing with Asian reference populations,the genetic distance (Rst) between Chaoshan Han and Guangdong Han was the smallest (0.0036),while it was relatively larger between Chaoshan Han and Gansu Tibetan population (0.0935).The multi-dimensional scaling (MDS) plot based on Rst values was similar to the results of clustering analysis.Conclusion Multiplex detection of the 27 Y-STR loci reveals a highly polymorphic genetic distribution in Chaoshan Han population,which demonstrates the important significance of Yfiler(R) Plus kit for establishing a Y-STR database,studying population genetics,and for good practice in forensic medicine.

Asian Ethnic Group Classification Model Using Data Mining / 대한법의학회지

In addition to identifying genetic differences between target populations, it is also important to determine the impact of genetic differences with regard to the respective target populations. In recent years, there has been an increasing number of cases where this approach is needed, and thus various statistical methods must be considered. In this study, genetic data from populations of Southeast and Southwest Asia were collected, and several statistical approaches were evaluated on the Y-chromosome short tandem repeat data. In order to develop a more accurate and practical classification model, we applied gradient boosting and ensemble techniques. To infer between the Southeast and Southwest Asian populations, the overall performance of the classification models was better than that of the decision trees and regression models used in the past. In conclusion, this study suggests that additional statistical approaches, such as data mining techniques, could provide more useful interpretations for forensic analyses. These trials are expected to be the basis for further studies extending from target regions to the entire continent of Asia as well as the use of additional genes such as mitochondrial genes.

Polymorphism Investigation on 15 STR Loci of Yunnan Bai Population / 昆明医科大学学报

Objective The study aimed to investigate 15 autosomal loci polymorphism(such as D3S1358 and TPOX)in Nujiang Bai nationality,in order to construct genetic basic data of Bai population and provide a foundation for population study and forensic cases. Methods Venous blood was collected from 124 unrelated Bai individuals in Nujiang,Yunnan province. DNA was extracted by classical organic solvent extraction. PCR technique was applied to amplify the sequence of autosomal loci. The products were measured by electrical fluoroscopy. The gene frequencies of 15 STR loci were investigated and genetic polymorphisms were analyzed. ResultsGene polymorphisms of 15 STR loci were detected and the distributions of genotype conformed with Hardy-Weinberg balance law(P > 0.05). The cumulative match probability(CPM)was 4.869×10-17,the cumulative excluding probability(CPE)was 99.999 99%,and the combined power of discrimination(CDP)was 99.999 97%. ConclusionThe 15 STR loci used in this study were highly polymorphic informative content in Bai population and could be applied to population study and forensic practice.

Establishment of a 15 Loci Multiplex Amplification System and the Genetic Poly-morphism in Xinjiang Uygur Population / 法医学杂志

Objective To develop a five fluorescence-labeled multiplex amplification system for 15 loci and study genetic polymorphism in Xinjiang Uygur population. Methods The STR loci were screened. The alleles were named according to the number of repeats by sequencing. The sensitivity, species specificity, identity and stability of the five fluorescence-labeled multiplex amplification system for the 15 loci were all tested. Then, the genetic polymorphism was analyzed in Xinjiang Uygur population and compared with other ethnic groups including Xizang Tibetan, Xiuyan Manchu, and Guangzhou Han pop-ulation. Results The 15 loci multiplex amplification system was established. The sensitivity was 0.3 ng with good species specificity, identity and stability. The distributions of genotype for 13 STR loci in Uygur population were in accordance with Hardy-Weinberg equilibrium with no genetic linkage between these loci. Most loci showed statistically significant among different populations. Conclusion The estab-lished system has application value in forensic evidence. The 13 STR loci in Uygur population have high polymorphisms to be the supplements to the existing loci.

Genetic diversity of 15 autosomal short tandem repeats loci using the AmpFLSTR ® Identifiler™ kit in a Bhil Tribe Population from Gujarat state, India.

MATERIALS AND METHODS: The genetic diversity and forensic parameters based on 15 autosomal short tandem repeats (STR) loci; D8S1179,D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317,D16S539, D2S1338, D19S433, vWA, TPOX, D18S51,D5S818, and FGA in AmpFLSTR® Identifiler™ kit from Applied Biosystems, Foster City, CA, USA were evaluated in saliva samples of 297 unrelated individuals from the Bhil Tribe population of Gujarat state, India to study genetic diversities and relatedness of this population with other national and international populations. RESUITS: Statistical analysis of the data revealed all loci were within Hardy-Weinberg Equilibrium expectations with the exception of the locus vWA (0.019) and locus D18S51 (0.016). The neighbour joining phylogeny tree and Principal Co-ordinate Analysis plot constructed based on Fst distances from autosomal STRs allele frequencies of the present study and other national as well as international populations show clustering of all the South Asian populations in one branch of the tree, while Middle Eastern and African populations cluster in a separate branch. CONCLUSION: Our findings reveal strong genetic affinities seen between the Indo-European (IE) speaking Bhil Tribe of Gujarat and Dravidian groups of South India.

Genetic Polymorphism of Nine Non-CODIS STR Loci in Hu-nan Province-based Chinese Han Population / 法医学杂志

Objective To determine the allelic frequency distribution and genetic parameters of nine non-CODIS DNA index systems of the short tandemrepeat (STR ) loci (D2S1772, D6S1043, D7S3048, D8S1132, D11S2368, D12S391, D13S325, D18S1364, and GATA198B05). Methods A total of 353 blood samples were collected, extracted, amplified, and analyzed fromunrelated healthy individuals of Han na-tionality in Hunan Province, China. Results O ne hundred and fourteen alleles were observed in the pop-ulation with corresponding allelic frequencies ranged from0.001 0 to 0.323 0. For all the nine non-CODIS STR loci, the observed genotypic data showed no significant deviations fromthe Hardy-W einberg equi-librium. The Ho, He, PIC, D P, and PE of the studied non-CODIS STR loci ranged from0.108 0 to 0.195 0, 0.805 0 to 0.892 0, 0.770 0 to 0.860 0, 0.925 0 to 0.966 0 and 0.607 0 to 0.780 0, respectively. Conclusion N ine non-CODIS STR loci have high degrees of polymorphisms, which may be useful in in-dividual forensic identification and parentage testing in forensic practice.

Linkage Disequilibrium and Mutation Rate Analysis of Sixteen X-STR Loci / 法医学杂志

Objective To assess the patterns oflinkage disequilibrium (LD ) of16 STR loci on X chrom o-som e and investigate the genetic stability. Methods G enom ic DNA samples extracted from blood stains from 500 unrelated individuals and 885 lineage m em bers from E astern C hinese H an population were genotyped through m ultiplex am plification using ID typerX-16 kit by our independent research followed by capillary electrophoresis. LD was assessed by PowerM arker v3.25 software and m utation rate of every locus was analyzed. Results LD were not found at the 16 X-STR loci. A llele m utations were observed at 10 loci. A m ong them , m utation rates of DXS6809 and DXS7132 were both up to 0.004 8. Conclusion W hen the 16 X-ST R loci included in ID typerX-16 kit were used for parentage testing, product princi-ples can be applied to calculate the likelihood, but m utation should be taken into consideration in the case that the genotypes do not m eet the genetic law(especially at DXS6809 and DXS7132).