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Objective Establish a typing system for Mycobacterium leprae based on polymorphic DNA structures known as short tandem repeats (STR). Design Assess 16 polymorphic STR for sensitivity, specificity and reproducibility in standard assays using reference strains of M. leprae. Results Primers for 16 STR loci were selected based on PCR product size and for their ability to sequence each STR locus from both directions. All primer pairs produced a visible PCR amplicon of appropriate size from PCR reactions containing 10 M. leprae cells. DNA sequences for each STR locus, except (AT) 15, was correctly identified as M. leprae-specific in replicate samples containing 1000 M. leprae using either the forward or reverse PCR primers. Twelve of 13 M. leprae STR loci were stable during passage in heavily infected armadillo tissues over a 5 year and 7 month infection cycle. Conclusions Certain M. leprae STR provide suitable targets for strain typing with the potential for grouping M. leprae with shared genotypes that may prove useful for establishing linkages between leprosy cases within geographical regions.

For the analysis of degraded DNA in disaster victim identification (DVI) and criminal investigations, single nucleotide polymorphisms (SNPs) have been recognized as promising markers mainly because they can be analyzed in short sized amplicons. Most SNPs are bi-allelic and are thereby ineffective to detect mixtures, which may lead to incorrect genotyping. We developed an algorithm to find non-binary (i.e. tri-allelic or tetra-allelic) SNPs in the NCBI dbSNP database. We selected 31 potential tri-allelic SNPs with a minor allele frequency of at least 10%. The tri-allelic nature was confirmed for 15 SNPs residing on 14 different chromosomes. Multiplex SNaPshot assays were developed, and the allele frequencies of 16 SNPs were determined among 153 Dutch and 111 Netherlands Antilles reference samples. Using these multiplex SNP assays, the presence of a mixture of two DNA samples in a ratio up to 1:8 could be recognized reliably. Furthermore, we compared the genotyping efficiency of the tri-allelic SNP markers and short tandem repeat (STR) markers by analyzing artificially degraded DNA and DNA from 30 approximately 500-year-old bone and molar samples. In both types of degraded DNA samples, the larger sized STR amplicons failed to amplify whereas the tri-allelic SNP markers still provided valuable information. In conclusion, tri-allelic SNP markers are suited for the analysis of degraded DNA and enable the detection of a second DNA source in a sample.

As a consequence of the close integration of cattle into the food chain of humans, forensically relevant cases involving cattle (Bos taurus) DNA analysis are common. However, scientific publications reporting the information content of the commonly used bovine short tandem repeat (STR) loci remains scarce. Population studies were performed for 16 polymorphic STR loci (BM1818, BM1824, BM2113, CSRM60, CSSM66, ETH3, ETH10, ETH225, HAUT27, ILSTS006, INRA023, SPS115, TGLA53, TGLA122, TGLA126, and TGLA227) including 4,162 randomly selected cattle representing 20 distinct breeds. The power of parental exclusion, expected and observed heterozygosity, probability of identity, and non-amplifying ("null") allele frequencies were calculated. Major differences existed in the information content between different cattle breeds. The selection of 16 STR loci, partially recommended by International Society for Animal Genetics as the minimum standard needed for bovine STR typing, was sufficient for forensic analysis. Furthermore, the efficacy of the loci was assessed in assigning unknown individuals to the correct breed based on genotype data. The individual assignment tests provided excellent success in several breeds.

Copy-number aberrations of the 22q11.2 region can lead to varied resulting and complex phenotypes. Routine screening for these common constitutional chromosomal abnormalities requires powerful tools. A competitive fluorescent multiplex STR polymorphism assay (CFMSA) was built for detecting these aberrations. With the introduction of an internal reference and distinguishable STR polymorphism markers, this competitive fluorescent multiplex STR polymorphism assay provides complementary information about polymorphism and gene dosage in one tube simultaneously, thereby enhancing the assay sensitivity. It was first tested in 110 normal controls, and was proven to have highly polymorphic and reliable gene dosage information. Then, 476 subjects with congenital heart defect were screened according to the testing strategy of the American Heart Association, and 17 deletions and 1 duplication of 22q11.2 were correctly identified. It is expected that this assay will serve as a cost-effective alternative to existing assays for routine, large-scale screening in all at-risk individuals with either deletion or duplication in 22q11.2.

Study results of variations in the X chromosome are useful tools in researching the genetic diversity of human populations and individual identification. We developed a 13 X chromosomal short tandem repeat (STR) multiplex system (DXS6807, DXS8378, DSX9902, DXS7132, DXS9898, DXS6809, DXS6789, DXS7424, DXS101, GATA172D05, HPRTB, DXS8377, DXS7423) amplified in one single polymerase chain reaction. DNA samples of 113 male and 108 female Taiwanese Han subjects were successfully analyzed using this 13 X-STR multiplex system. The distributions of allele frequencies were examined for independence. DXS8377, DXS101, DXS6789, and DXS6809 were found to be the most polymorphic markers in this study. High values of discrimination power and mean exclusion chance without significant evidence of association between these markers were obtained. In conclusion, this 13 X chromosomal STR multiplex system offers considerable forensic efficiency and may be useful in forensic identification casework.

A single multiplex PCR assay capable of simultaneously amplifying nine canine-specific autosomal STR markers (FH3210, FH3241, FH2004, FH2658, FH4012, REN214L11, FH2010, FH2361 and the newly described C38) was developed for individual identification and parentage testing in domestic dogs. In order to increase genotyping efficiency, amplicon sizes were optimized for a 90-350 bp range, with fluorescently labelled primers for use in Applied Biosystems, Inc., platforms. The performance of this new multiplex system was tested in 113 individuals from a case-study population and 12 random dogs from mixed-breed origin. Co-dominant inheritance of STR alleles was investigated in 101 father, mother and son trios. Expected heterozygosity values vary between 0.5648 for REN214L11 and 0.9050 for C38. The high level of genetic diversity observed for most markers provides this multiplex with a very high discriminating power (matching probability =1.63/10 10 and matching probability among siblings = 4.9/10 3 ). Allele sequences and a proposal for standardized nomenclature are also herein presented, aiming at implementing the use of this system in forensic DNA typing and population genetic studies. This approach resulted in an optimized and well-characterized canine DNA genotyping system that is highly performing and straightforward to integrate and employ routinely. Although this STR multiplex was developed for use and tested in a case-study population, the Portuguese breed Cao de Gado Transmontano, it proved to be useful for general identification purposes or parentage testing.

Since the method of minisatellites for the identification of humans with restriction-fragment-length polymorphism (RFLP) was reported by Jeffreys et al. in 1985, the revolution has taken place within the field of forensic genetics. In the crime case, the DNA markers have advantages over the traditional biological markers and the DNA technologies have been improved continuously. Today, the multiplex STR (short tandem repeat analysis) polymorphisms have become the major and widely used method for human identification test both in criminal investigation and mass disaster victim identification.

Current forensic DNA typing is conducted in approximately 8–10 h. Steps include DNA extraction, quantification, polymerase chain reaction (PCR) amplification of multiple short tandem repeat (STR) loci, capillary electrophoresis separation with fluorescence detection, data analysis and DNA profile interpretation. The PCR amplification portion of the workflow typically takes approximately 3 h with standard thermal cycling protocols. Here we demonstrate a rapid cycling protocol that amplifies 15 STR loci and the sex-typing marker amelogenin from the Identifiler STR typing kit in less than 36 min. This rapid protocol employs commercially available polymerases and the widely used GeneAmp 9700 thermal cycler. Complete concordance of STR allele calls (for 60 samples) between the rapid and standard thermal cycling protocols were observed although there was incomplete adenylation at several of the loci examined and some PCR artifacts were detected. Using less than 750 pg of template DNA and 28 cycles, STR peaks for all loci were above a 150 relative fluorescent unit (RFU) detection threshold with fully adequate inter-locus balance and heterozygote peak height ratios of greater than 0.84.

This paper describes a newly devised autosomal short tandem repeat (STR) multiplex polymerase chain reaction (PCR) systems for 10 loci (D1S1656, D2S1353, D8S1132, D12S1090, D14S608, D18S535, D19S253, D20S480, D21S226, and D22S689) unlinked to the core STR loci (non-CODIS loci). Of 252 samples taken from the Japanese population, PCR products ranged in length from 107 bp to 319 bp. No significant deviations from Hardy–Weinberg equilibrium were observed at any of the 10 loci. The accumulated power of discrimination and power of exclusion for the 10 loci were 0.999999999998 and 0.99991, respectively. We conclude that the present multiplex system for the 10 non-CODIS loci represents a powerful tool for forensic applications.

Background Two cases of paternity dispute, examined with 17 autosomal short tandem repeats signified a possible single and double maternal mismatch at vWA and D8S1179/D21S11 loci in the children under investigation. Methods Seventeen autosomal STR loci were analyzed using AmpF l STR Identifiler, PowerPlex 16 kits. Six STR markers on X chromosome were amplified and analyzed. Mutated alleles were amplified, cloned in pCR®II-Topo® vector, sequenced and investigated. Results In case S1 the vWA locus indicated an allele mismatch with the mother. All the vWA alleles on amplification, cloning and sequencing depicted an increase of 2 repeats in the child. In case D1 maternal child inconsistency at D8S1179 and D21S11 loci was observed. The alleles were amplified, cloned and sequenced to analyze the repeat structure. Increase of 1 repeat in D8S1179 locus and an insertion mutation in D21S11 locus between the mother and questioned child were confirmed. A complete match with the 17 autosomal loci of the father and 6 X chromosome STR loci of the mother was observed in both the cases. Conclusion This is the first report of a maternally transmitted single mismatch at vWA locus and double mismatch at D8S1179 and D21S11 loci due to increase/mutation of the repeat in the paternity DNA testing. The results of nucleotide sequencing and STR analyses convincingly established that the suspected father and the mother are undeniably the biological parents of the questioned child.

The evaluation of four pairs of tightly linked chromosome X (ChrX) short tandem repeat (STR)s at Xp22, Xq12, Xq26 and Xq28 led to the creation of the Argus X 8 multiplex amplification kit. These eight STRs are distributed as four closely linked pairs over the entire X-chromosome, and for practical reasons, they are assigned to four linkage groups 1-4. To achieve a further considerable enhancement in discrimination power, we suggest to include additional markers. A recent paper referred to the earlier evaluation of STR clusters at Xq12, Xq26 and Xq28, and here we present the pending data of linkage group 1 at Xp22. The newly established STR updates the Xp22 STR cluster which now presents three polymorphic markers: DXS10148 (PIC = 0.8556), DXS10135 (PIC = 0.9093) and DXS 8378 (PIC = 0.6454). Typing of 398 X-chromosomes provided 278 different and 200 unique haplotypes. All the other haplotypes observed appeared with frequencies in the range between 0.005 and 0.015. Considering this STR triple in the context with the three further triple clusters Xq12, Xq26 and Xq28 published earlier, we announced the development of a next generation of a ChrX STR cluster typing kit.

Short tandem repeat (STR) markers are extensively being used for human identification as well as paternity and forensic case work. X-chromosome STR (X-STR) markers are a powerful complementary system especially in deficiency paternity testing. Many X-linked microsatellites have been evaluated but further studies are required to determine population specific statistics. Here, we report allele frequencies of 13 X-linked microsatellites (DXS8378, DXS9902, DXS6810, DXS7132, DXS981, DXS6793, DXS6801, DXS6789, GATA172D05, HPRTB, GATA31E08, DXS8377, and DXS7423) in the Pakistani population. Blood samples were collected from individuals representing all major ethnic groups of the Pakistan population. A total of 5-18 alleles were observed for each locus and altogether 109 alleles for all 13 X-STR loci. Heterozygosity in females ranged from 0.524 to 0.884. No significant deviation was observed from Hardy-Weinberg equilibrium for all 13 microsatellites. In addition, there was no evidence of linkage disequilibrium in any pairs of these markers. These results strongly suggest that the X-linked microsatellites described here can potentially serve as an extension to autosomal systems currently used in parentage analysis and forensic case work.

The polymorphism distributions of 15 STR loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, VWA, TPOX, D18S51, D5S818, and FGA) were investigated in a Tibetan population by multiplex PCR amplification using five fluorochromes (6FAM, VIC, NED, PET, LIZ). Gene frequency, discrimination power (DP), heterozygosity (H), polymorphism information content (PIC) and probability of paternity exclusion (EPP) were calculated, and all loci were tested for Hardy-Weinberg equilibrium. Results indicate that the gene frequency of these 15 STR loci is in Hardy-Weinberg equilibrium. The DP is at 0.7555-0.9602, H is at 0.5651-0.8530, PIC is at 0.5528-0.8456, and EPP is at 0.3811-0.8549. Cumulative DP of the 15 STR is 0.99999999, and cumulative EPP is 0.999999997. Therefore, these 15 STR loci can be used as genetic markers of Tibetan populations in anthropological studies, linkage analysis of genetic diseases, individual identification and paternity testing in forensic medicine.

DNA typing of degraded DNA samples can be a challenging task when using the current commercially available multiplex short tandem repeat (STR) analysis kits. However, the ability to type degraded DNA specimens improves by redesigning current STR marker amplicons such that smaller sized polymerase chain reaction (PCR) products are generated. In an effort to increase the amount of information derived from these types of DNA samples, the AmpFlSTR MiniFiler PCR Amplification Kit has been developed. The kit contains reagents for the amplification of eight miniSTRs which are the largest sized loci in the AmpFlSTR Identifiler PCR Amplification Kit (D7S820, D13S317, D16S539, D21S11, D2S1338, D18S51, CSF1PO, and FGA). Five of these STR loci (D16S539, D21S11, D2S1338, D18S51, and FGA) also are some of the largest loci in the AmpFlSTR SGM Plus kit. This informative nine-locus multiplex, which includes the gender-identification locus Amelogenin, has been validated according to the FBI/National Standards and SWGDAM guidelines. Our results demonstrate significant performance improvements in models of DNA degradation, PCR inhibition, and nonprobative samples when compared to the AmpFlSTR Identifiler and SGM Plus kits. These data support that the MiniFiler kit will increase the likelihood of obtaining additional STR information from forensic samples in situations in which standard STR chemistries fail to produce complete profiles.

We investigated 14 polymorphic STR loci (D1S2142, D2S1360, D3S1545, D7S1517, D10S2325, D12S391, D13S1492, D14S306, D15S659, D16S3253, D18S1270, D19S253, D20S470, D21S1437) which are not included in the standard sets of forensic loci (CODIS) in a sample of 216 unrelated healthy southeast Chinese individuals. The studied loci were highly informative and did not show departures from Hardy-Weinberg equilibrium. The accumulated powers of discrimination and power of exclusion for the 14 loci were 99.9999999999 and 99.999998%, respectively. No linkage was observed between the 14 loci and the traditional set of STR markers included in commercially available kits (the AmpFLSTR IdentifilerTM 15 System loci). We thus considered the studied 14 STRs are informative and when necessary, can be used as the candidate genetic markers in the study and application in genetics and forensic practice.

Pigeon racing appeals to many in Taiwan, due in part to the potential large financial gains based on illegal betting. The races are unregulated with frequent examples of fraud, such as substitution of one bird for a substandard one. There is no test available to reliably verify the bloodline of pigeons and thus help to resolve such disputes. In this study, we describe a multiplex PCR amplification system combining 7 STR loci and a chromo-helicase DNA binding gene (CHD) marker for the identification of individual pigeons. The cumulative power of discrimination (CPd) of the 7 STR loci was 0.99999234 based upon our population study. The cumulative probability of paternity (CPP) when used in paternity testing of 17 pigeon families ranged from 97.36 to 99.99% and the combined probability of exclusion (CPE) was 0.9325 for these seven STR markers. The statistical data illustrates the potential of this system to be used in pigeon individualization and paternity testing. Furthermore, the established STR system could be also used in the other areas, such as ecology, population genetics, and avian breeding programs.

The goal of the study was to develop a STR multiplex ("Paterniplex") that is - as supplement to commercially available multiplex kits like the Identifiler® kit (Applied Biosystems, Foster City, CA) - suitable for solving complex paternity cases such as deficiency cases or cases with mutations. The Paterniplex comprises the nine highly polymorphic STRs D8S1132, D7S1517, D10S2325, D12S391, Se33, D17S976, Penta E, Penta D and FGA in addition to Amelogenin as sex determination marker. The loci were selected because of their high degree of polymorphism (higher than that of the widely used TH01 marker). Only one locus, FGA, is shared with the Identifiler kit to avoid sample mix up. The study further gives details on the population genetics of the loci in a German Caucasian population (allelic distribution, Hardy-Weinberg Equilibrium and forensic efficiency markers such as the Discriminating Power) and three examples for cases that could not be solved using commercially available kits alone, but using the Paterniplex in addition to a commercial kit.

Largely due to technological progress coming from the Human Genome and International HapMap Projects, the issue has been raised in recent years within the forensic DNA typing community of the potential for single nucleotide polymorphism (SNP) markers as possible replacements of the currently used short tandem repeat (STR) loci. Our human identity testing project team at the U.S. National Institute of Standards and Technology (NIST) has explored numerous SNP and STR loci and assays as well as developing miniSTRs for degraded DNA samples. Based on their power of discrimination, use in deciphering mixture components, and ability to be combined in multiplex assays in order to recover information from low amounts of biological material, we believe that STRs rather than SNPs will fulfill the dominant role in human identity testing for the foreseeable future. However, SNPs may play a useful role in specialized applications such as mitochondrial DNA (mtDNA) testing, Y-SNPs as lineage markers, ancestry informative markers (AIMs), the prediction of phenotypic traits, and other potential niche forensic casework applications.

It has proved difficult to find strong and replicable genetic linkages for complex diseases, since each susceptibility gene makes only a modest contribution to onset. This is partly because high-efficacy genetic markers are not usually available. The aim of this article is to explore the possibility that the total number of tandem repeats in one STR locus, rather than the frequencies of different alleles, is a higher efficacy quantitative genetic marker. DNA samples were collected from schizophrenic patients and from a control population. Alleles of the short tandem repeats (STR) loci D3S1358, vWA, and FGA were determined using the STR Profiler Plus PCR amplification kit. The two groups did not differ statistically in the frequencies of alleles at the D3S1358, vWA, or FGA loci. However, a significant difference was obtained in the vWA locus when the total number of core unit repeats was compared between the schizophrenia and control groups (33.28 ± 2.61 vs. 32.35 ± 2.58, P < 0.05). It seems that the number of STR repeats may be a new, quantitative, and higher efficacy genetic marker for directly indicating genetic predisposition to complex hereditary diseases such as schizophrenia.

In search of new efficient markers for genetic diagnostics of hemophilia A, two tri-nucleotide microsatellite repeats (STR) at chromosome X loci, which flank coagulation factor VIII gene (F8), namely STR HA472—CTT-repeat, which is localized adjacent to the GAB3 gene 163 kb apart from the 3′ end of the F8 gene and STR HA544—repeat (CTT) x (ATT) y located at a distance of 375 kb from the 5′ end of the F8 gene were discovered. Detailed analysis using PCR and sequencing has shown that STR HA472 contains two long variable CTT-blocks separated by small spacer CCTCCC. The location of recognition site of restriction endonuclease MnlI (CCTC) in the spacer permits to test differentially the polymorphic blocks and thus to increase the analysis informativity. STR HA544 is also represented by two polymorphic blocks (CTT and ATT), for separate amplification of which highly informative PCR amplification assays were elaborated. The study has been done using DNA samples of 212 individuals (125 women) from 48 families with hemophilia A carriers. Our results point to Mendelian inheritance of the markers studied, a high number of allelic variants and high heterozygosity, which was 90 and 100% for HA544 and HA472, respectively. This permitted us to use these data for practical gene diagnostics of the carriers and prenatal diagnostics of hemophilia A. In addition to high informativity STR HA472 and HA544 are highly important for diagnostics as they are located at a shorter distance than other known extragenic polymorphisms of the F8 gene. In contrast to dinucleotide repeats, trinucleotide repeats are readily tested, not requiring high-resolution electrophoretic systems. In addition, they are located on the opposite sites of the F8 gene. This permits to control homologous recombination events in the locus and thus to prevent diagnostic mistakes.

Background We investigated 2 cases of paternity dispute with 17 autosomal short tandem repeats (STR), that indicated a mismatch to the maternally and paternally inherited allele at D18S51 locus in children under inquiry. Methods 17 autosomal and Y STR loci were analyzed using AmpFlSTR Identifiler, PowerPlex 16, AmpFlSTR®Y-filer™ kits. The mitochondrial DNA hypervariable regions HV1 and HV2 and 6 STR markers on X chromosome were amplified and sequenced. Results In case M1, allelic representation in the mother, questioned child and suspected father was 14/19, 12/20 and 12/14 respectively. A complete match with the mother at 6 X STR loci and mitochondrial hypervariable regions was observed. In case F1, allelic representation was 13/14, 14/20 and 16/18 respectively. A complete match with the father at 17 Y chromosome STR loci was observed. D18S51 sequence analysis indicates the expansion of 1 repeat in M1 and 2 repeats in F1 leading to allele mismatch in the child. Conclusion The probability of maternity and paternity were 0.999999 and 0.999999 respectively. This is the first report of a maternally/paternally transmitted D18S51 mutations in the paternity DNA testing. These results conclusively determined that the mother and suspected father are the biological parents of the questioned children in both the cases.

To define the Y-chromosome genetic structure in Apennine populations, 17 Y-chromosome short tandem repeats (Y-STRs) and 37 Y-single nucleotide polymorphisms (Y-SNPs) were typed in 162 subjects living in the upland area of the Marches (Central Italy). A total number of 155 haplotypes (haplotype diversity was 0.9994) and 14 SNP haplogroups were observed. Testing high-resolution Y-chromosome data sets, e.g. using Yfiler and SNPs, increases the discriminatory capacity in individual identification for forensic purposes. It is also useful in autochthonous population and micro-population studies to highlight the most informative loci for evolutionary aims.

Short tandem repeats (STRs) are short tandemly repeated DNA sequences that involve a repetitive unit of 1–6 bp. Because of their polymorphisms and high mutation rates, STRs are widely used in biological research. Strand-slippage replication is the predominant mutation mechanism of STRs, and the stepwise mutation model is regarded as the main mutation model. STR mutation rates can be influenced by many factors. Moreover, some trinucleotide repeats are associated with human neurodegenerative diseases. In order to deepen our knowledge of these diseases and broaden STR application, it is essential to understand the STR mutation process in detail. In this review, we focus on the current known information about STR mutation.

Short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs) have been already used to perform noninvasive prenatal paternity testing from maternal plasma DNA. The frequently used technologies were PCR followed by capillary electrophoresis and SNP typing array, respectively. Here, we developed a noninvasive prenatal paternity testing (NIPAT) based on SNP typing with maternal plasma DNA sequencing. We evaluated the influence factors (minor allele frequency (MAF), the number of total SNP, fetal fraction and effective sequencing depth) and designed three different selective SNP panels in order to verify the performance in clinical cases. Combining targeted deep sequencing of selective SNP and informative bioinformatics pipeline, we calculated the combined paternity index (CPI) of 17 cases to determine paternity. Sequencing-based NIPAT results fully agreed with invasive prenatal paternity test using STR multiplex system. Our study here proved that the maternal plasma DNA sequencing-based technology is feasible and accurate in determining paternity, which may provide an alternative in forensic application in the future.

Chromosome Y microsatellites seem to be ideal markers to delineate differences between human populations. They are transmitted in uniparental and they are very sensitive for genetic drift. This review will highlight the importance of the Y- Chromosome as a tool for tracing human evolution and describes some details of Y-chromosomal short tandem repeat (STR) analysis. Among them are: microsatellites, amplification using polymerase chain reaction (PCR) of STRs, separation and detection and advantages of X-chromosomal microsatellites. Key words : Forensic, population, review, STR, Y- chromosome.

Background For 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. Findings The 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. Conclusions Different 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.

The aim of this study was of twofold. One was to determine the genetic structure of Iraq population and the second objective of the study was to evaluate the importance of these loci for forensic genetic purposes. FTA® Technology (FTA™ paper DNA extraction) utilized to extract DNA. Twenty (20) STR loci and Amelogenin), including D3S1358, D13S317, Penta E, D16S539, D18S51, D2S1338, CSF1PO, Penta D, THO1, vWA, D21S11, D7S820, TPOX, D8S1179, FGA, D2S1338, D5S818, D6S1043, D12S391, D19S433 and Amelogenin amplified by using power plex21® kit. Polymerase chain reaction (PCR) products detected by genetic analyzer 3730xL then data analyzed by PowerStatsV1.2. Based on the allelic frequencies, several statistical parameters of genetic and forensic efficiency have been estimated. This includes the homozygosity and heterozygosity, effective number of alleles (n), the polymorphism information content (PIC), the power of discrimination (DP) and the power of exclusion (PE). The power of discrimination values for all tested loci was from 75 to 96%; therefore, those loci can be safely used to establish a DNA-based database for Iraq population. The high PIC values of the selected markers confirm their usefulness for genetic polymorphism studies and linkage mapping programs in human as well. The mean heterozygosity observed, is expected to have mean PIC values across the 20 loci which were 0.77, 0.81 and 0.78, respectively, indicating high gene diversity. Keywords: Autosomal STR, genetic variation, Iraq, statistical parameters. African Journal of Biotechnology , Vol 13(11), 1210-1218

We have previously developed a panel of 40 insertion-deletion (INDEL) human DNA polymorphisms that was proven to ad-equately cover the span of global human genetic diversity. The panel was found to have very low matching probabilities with respect to both the global and Brazilian populations. To optimize the panel for application with degraded DNA samples, which are commonly encountered in fo-rensic analysis, we have significantly reduced the amplicon size of the INDELs and developed a new multiplex panel. The panel has an ampli-con size ranging from 50 to 153 base pairs, with a mean of 93 base pairs. It could be amplified by polymerase chain reaction in two multiplex re-actions, which were then combined for electrophoretic separation and identification of the individual products in the ABI3130 four-color DNA analyzer. The results of the new panel were fully validated.

Poaching and trans-boundary trafficking of tigers and body parts are threatening the world's last remaining wild tigers. Development of an efficient molecular genetic assay for tracing the origins of confiscated specimens will assist in law enforcement and wildlife forensics for this iconic flagship species. We developed a multiplex genotyping system “tigrisPlex” to simultaneously assess 22 short tandem repeat (STR, or microsatellite) loci and a gender-identifying SRY gene, all amplified in 4 reactions using as little as 1 ng of template DNA. With DNA samples used for between-run calibration, the system generates STR genotypes that are directly compatible with voucher tiger subspecies genetic profiles, hence making it possible to identify subspecies via bi-parentally inherited markers. We applied “tigrisPlex” to 12 confiscated specimens from Russia and identified 6 individuals (3 females and 3 males), each represented by duplicated samples and all designated as Amur tigers (Panthera tigris altaica) with high confidence. This STR multiplex system can serve as an effective and versatile approach for genetic profiling of both wild and captive tigers as well as confiscated tiger products, fulfilling various conservation needs for identifying the origins of tiger samples.

Short tandem repeats (STRs) are implicated in dozens of human genetic diseases and contribute significantly to genome variation and instability. Yet profiling STRs from short-read sequencing data is challenging because of their high sequencing error rates. Here, we developed STR-FM, short tandem repeat profiling using flank-based mapping, a computational pipeline that can detect the full spectrum of STR alleles from short-read data, can adapt to emerging read-mapping algorithms, and can be applied to heterogeneous genetic samples (e.g., tumors, viruses, and genomes of organelles). We used STR-FM to study STR error rates and patterns in publicly available human and in-house generated ultradeep plasmid sequencing data sets. We discovered that STRs sequenced with a PCR-free protocol have up to ninefold fewer errors than those sequenced with a PCR-containing protocol. We constructed an error correction model for genotyping STRs that can distinguish heterozygous alleles containing STRs with consecutive repeat numbers. Applying our model and pipeline to Illumina sequencing data with 100-bp reads, we could confidently genotype several disease-related long trinucleotide STRs. Utilizing this pipeline, for the first time we determined the genome-wide STR germline mutation rate from a deeply sequenced human pedigree. Additionally, we built a tool that recommends minimal sequencing depth for accurate STR genotyping, depending on repeat length and sequencing read length. The required read depth increases with STR length and is lower for a PCR-free protocol. This suite of tools addresses the pressing challenges surrounding STR genotyping, and thus is of wide interest to researchers investigating disease-related STRs and STR evolution.

Microsatellites of the X-chromosome have been increasingly studied in recent years as a useful tool in forensic analysis. This review describes some details of X-chromosomal short tandem repeat (STR) analysis. Among them are: microsatellites, amplification using polymerase chain reaction (PCR) of STRs, PCR product evaluation, PCR product purification, separation and detection, data analysis of STR by Identity Software, locus information and allele frequencies for X-chromosomal STR in different populations (DXS101, DXS7423, DXS8377, DXS6789, DXS6807 genetic loci) and advantages of X-chromosomal micro-satellites. In forensic casework and DNA databases, polymorphism in STR is important as a forensic genetic marker. Key words: Short tandem repeat (STR) loci, forensic, interpretation.

Capillary electrophoresis (CE) and multiplex amplification with fluorescent tagging have been routinely used for STR typing in forensic genetics. However, CE-based methods restrict the number of markers that can be multiplexed simultaneously and cannot detect any intra-repeat variations within STRs. Several studies already have indicated that massively parallel sequencing (MPS) may be another potential technology for STR typing. In this study, the prototype PowerSeq(™) Auto System (Promega) containing the 23 STR loci and amelogenin was evaluated using Illumina MiSeq. Results showed that single source complete profiles could be obtained using as little as 62 pg of input DNA. The reproducibility study showed that the profiles generated were consistent among multiple typing experiments for a given individual. The mixture study indicated that partial STR profiles of the minor contributor could be detected up to 19:1 mixture. The mock forensic casework study showed that full or partial profiles could be obtained from different types of single source and mixture samples. These studies indicate that the PowerSeq Auto System and the Illumina MiSeq can generate concordant results with current CE-based methods. In addition, MPS-based systems can facilitate mixture deconvolution with the detection of intra-repeat variations within length-based STR alleles.

In order to find out the characteristics of genetic mutations in 15 short tandem repeat (STR) loci, 3734 parentage cases were analyzed using AmpFlSTR Sinofiler kit. The allele source, mutation rate, and mutation rule of the STR loci were determined. Seventy mutations were observed in all cases for paternity testing. Among 15 STR loci, the highest mutation rate was observed in D12S391 (0.21 %), but the D5S818 gene mutation rate was relatively low (0.02 %). One-step mutation cases accounted for 95.7 % of all of the cases monitored. And the mutations in this study mainly showed paternal mutation (64/70). The research results are of great significance for identification and paternity tests and for the improvement of genetic studies on Chinese population in the future.

Background Whole-genome sequencing is performed routinely as a means to identify polymorphic genetic loci such as short tandem repeat loci. We have developed a simple tool, called pSTR Finder, which is freely available as a means of identifying putative polymorphic short tandem repeat (STR) loci from data generated from genome-wide sequences. The program performs cross comparisons on the STR sequences generated using the Tandem Repeats Finder based on multiple-genome samples in a FASTA format. These comparisons generate reports listing identical, polymorphic, and different STR loci when comparing two samples. Methods The web site http://forensic.mc.ntu.edu.tw:9000/PSTRWeb/Default has been developed as a means to identify polymorphic STR loci within complex mass genome sequences. The program was developed to generate a series of user-friendly reports. Results As proof of concept for the program, four FASTA genome sequence samples of human chromosome X (AC_000155.1, CM000685.1, NC_018934.2, and CM000274.1) were obtained from GenBank and were analyzed for the presence of putative STR regions. The sequences within AC-000155.1 were used as an initial reference sequence from which there were 5443 identical and 4305 polymorphic STR loci identified using a repeat unit of 1–6 and 10 bp as the flanking sequence either side of the putative STR loci. A reliability test was used to compare five FASTA samples, which had sections of DNA sequence removed to mimic partial or fragmented DNA sequences, to determine whether pSTR Finder can efficiently and consistently find identical, polymorphic, and different STR loci. Conclusions From the mass of DNA sequence data, the project was found to reproducibly identify polymorphic STR loci and generate user-friendly reports detailing the number and location of these potential polymorphic loci. This freely available program was found to be a useful tool to find polymorphic STR within whole-genome sequence data in forensic genetic studies. Electronic supplementary material The online version of this article (doi:10.1186/s13323-015-0027-x) contains supplementary material, which is available to authorized users.

Background: DNA profiling with sets of highly polymorphic autosomal short tandem repeat (STR) markers has been applied in various aspects of human identification in forensic casework for nearly 20 years. However, in some cases of complex kinship investigation, the information provided by the conventionally used STR markers is not enough, often resulting in low likelihood ratio (LR) calculations. In these cases, it becomes necessary to increment the number of loci under analysis to reach adequate LRs. Recently, it has been proposed that single nucleotide polymorphisms (SNPs) could be used as a supportive tool to STR typing, eventually even replacing the methods/markers now employed. Methods: In this work, we describe the results obtained in 7 revised complex paternity cases when applying a battery of STRs, as well as 52 human identification SNPs (SNPforID 52plex identification panel) using a SNaPshot methodology followed by capillary electrophoresis. Results: Our results show that the analysis of SNPs, as complement to STR typing in forensic casework applications, would at least increase by a factor of 4 total PI values and correspondent Essen-Möllerʼs W value. Conclusions: We demonstrated that SNP genotyping could be a key complement to STR information in challenging casework of disputed paternity, such as close relative individualization or complex pedigrees subject to endogamous relations.

The next-generation sequencing (NGS) method has been utilized to analyze short tandem repeat (STR) markers, which are routinely used for human identification purposes in the forensic field. Some researchers have demonstrated the successful application of the NGS system to STR typing, suggesting that NGS technology may be an alternative or additional method to overcome limitations of capillary electrophoresis (CE)-based STR profiling. However, there has been no available multiplex PCR system that is optimized for NGS analysis of forensic STR markers. Thus, we constructed a multiplex PCR system for the NGS analysis of 18 markers (13CODIS STRs, D2S1338, D19S433, Penta D, Penta E and amelogenin) by designing amplicons in the size range of 77-210 base pairs. Then, PCR products were generated from two single-sources, mixed samples and artificially degraded DNA samples using a multiplex PCR system, and were prepared for sequencing on the MiSeq system through construction of a subsequent barcoded library. By performing NGS and analyzing the data, we confirmed that the resultant STR genotypes were consistent with those of CE-based typing. Moreover, sequence variations were detected in targeted STR regions. Through the use of small-sized amplicons, the developed multiplex PCR system enables researchers to obtain successful STR profiles even from artificially degraded DNA as well as STR loci which are analyzed with large-sized amplicons in the CE-based commercial kits. In addition, successful profiles can be obtained from mixtures up to a 1:19 ratio. Consequently, the developed multiplex PCR system, which produces small size amplicons, can be successfully applied to STR NGS analysis of forensic casework samples such as mixtures and degraded DNA samples.

“The science of deduction and analysis is one which can only be acquired by long and patient study.”

BACKGROUND Non-syndromic autosomal recessive intellectual disability (NS-ARID) is an extremely heterogeneous genetic disorder. Therefore, to investigate these genes, more research is required. One approach to investigate the NS-ARID loci is homozygosity mapping which requires appropriate STR markers within or flanking the gene/s of interest. In this research, we aimed to find novel STRs for two common NS-ARID genes (TUSC3 and NSUN2) and, in addition, to identify allele frequencies of those STR markers. METHODS The study group included 119 unrelated healthy individuals. STR markers were investigated using the UCSC genome browser web site and SERV software. Genotyping was determined by multiplex PCR. Data were evaluated using Gene Mapper software. Allele frequencies and observed heterozygosity rates were calculated using PowerStatV12. Deviation from Hardy-Weinberg equilibrium and expected heterozygosity were assessed using the DNAView software. RESULTS In total, 56 alleles were detected. According to our research, D8TUSC3SU8.3 and D5NSUN2SU0.5 were the most informative STR markers in MRT7 and MRT5 loci, respectively and showed a high percentage of heterozygosity in Iranian population. The observed range of allele frequencies was from 3.4% to 32.4% and 0.8% to 18.9% for MRT5 and MRT7 loci, respectively. Further, we have evaluated other statistical surveys of these STR markers and discovered that all of the six listed STRs were informative and five meet the Hardy-Weinberg equilibrium for the tester group. CONCLUSIONS Finding novel STRs, with high allele heterozygosity, is one of the most significant current finding in the present study for the two common NSARID genes. The recognized heterozygosity of these markers make MRT flanking STR markers very efficient to be used in diagnostic medical genetics labs or homozygosity mapping on NS-ARID.

Multiplex polymerase chain reaction (PCR) enables examination of many loci simultaneously, and this multi-locus genotyping information can increase interpretation capabilities beyond what is available from a single locus. Short tandem repeat (STR) profiles can be illustrated with simple triangles, line drawings, or more sophisticated tools for illustrating electropherograms. This chapter addresses single-source samples. An understanding of expected behavior of single-source DNA samples is important prior to attempting DNA mixtures containing multiple contributors.

Aim To systemically select and evaluate short tandem repeats (STRs) on the chromosome 14 and obtain new STR loci as expanded genotyping markers for forensic application. Methods STRs on the chromosome 14 were filtered from Tandem Repeats Database and further selected based on their positions on the chromosome, repeat patterns of the core sequences, sequence homology of the flanking regions, and suitability of flanking regions in primer design. The STR locus with the highest heterozygosity and polymorphism information content (PIC) was selected for further analysis of genetic polymorphism, forensic parameters, and the core sequence. Results Among 26 STR loci selected as candidates, D14S739 had the highest heterozygosity (0.8691) and PIC (0.8432), and showed no deviation from the Hardy-Weinberg equilibrium. 14 alleles were observed, ranging in size from 21 to 34 tetranucleotide units in the core region of (GATA)9-18 (GACA)7-12 GACG (GACA)2 GATA. Paternity testing showed no mutations. Conclusion D14S739 is a highly informative STR locus and could be a suitable genetic marker for forensic applications in the Han Chinese population.

Background : The cytochrome P450 (CYP) 3A5 enzyme contributes to the metabolism of many drugs. Single nucleotide polymorphisms in the CYP3A5 gene ( CYP3A5 ⁎ 3C and CYP3A5 ⁎ 6 ) are associated with decreased CYP3A5 expression in the liver. We designed a multiplex genotyping assay to detect the CYP3A5 ⁎ 3C and CYP3A5 ⁎ 6 polymorphisms in a single polymerase chain reaction (PCR) and a single pyrosequencing reaction. Methods : A multiplex PCR assay was designed to simultaneously amplify 2 fragments, one containing the CYP3A5 ⁎ 3C polymorphism and the other containing the CYP3A5 ⁎ 6 polymorphism. Following PCR, multiplex genotyping was performed with pyrosequencing analysis. Results : Patient samples ( n = 69) were analyzed for the CYP3A5 ⁎ 3C and CYP3A5 ⁎ 6 polymorphisms using the multiplex PCR-pyrosequencing assay. Genotypes obtained by the multiplex reaction were in 100% concordance with genotypes obtained using simplex PCR-pyrosequencing ( n = 69) and direct DNA sequencing ( n = 29). Conclusions : The advantage of this method is that the CYP3A5 ⁎ 3C and CYP3A5 ⁎ 6 polymorphism can be amplified in a single PCR reaction and genotyped in a single pyrosequencing reaction. This combined approach improves the time-efficiency and decreases the cost of CYP3A5 genotyping.

26 Y chromosome short tandem repeat (STR) loci were amplified in a sample of 856 unrelated males from Bhutan, using two multiplex polymerase chain reaction (PCR) assays. The first multiplex is the Y-STR 20plex described by Butler et al. [J.M. Butler, R. Schoske, P.M. Vallone, M.C. Kline, A.J. Redd, M.F. Hammer, A novel multiplex for simultaneous amplification of 20 Y chromosome STR markers, Forensic Sci. Int. 129 (2002) 10-24], and the second is a novel (but overlapping) 14plex that targets six additional Y-STRs (DYS425, DYS434, DYS435, DYS436, DYS461, DYS462) and also amplifies the amelogenin locus. The 26-loci give a discriminating power of 0.9957, though even at this resolution one haplotype occurs 24 times. We identify novel alleles at five loci and microvariants at a further three, which were characterised by sequencing. Extended (11-locus) haplotypes for these samples have been submitted to the Y-STR Haplotype Reference Database (YHRD).

Two multiplex polymerase chain reaction systems for the automated profiling of 12 X-chromosomal short tandem repeat (STR) markers were developed. Multiplex A consisted of DXS6789, DXS6809, GATA172D05, DXS101, DXS8378, and DXS8377. Multiplex B consisted of DXS7132, DXS6800, DXS6801, DXS7424, HPRTB, and DXS10011. The set of amplified X-STRs was designed to include groups of closely linked markers (DXS101-DXS7424 and DXS6789-DXS6801-DXS6809) to generate highly informative haplotypes for kinship testing. A population genetics study of the 12 X-STRs was conducted in a northwestern Italian population sample (n=160, 80 women and 80 men). A diallelic pattern at locus DXS6789 was observed in one man.

We investigated 15 polymorphic short tandem repeat (STR) loci (D1S1656, D7S1517, D8S306, D8S639, D9S304, D10S2325, D11S488, D12S391, D14S608, D16S3253, D17S976, D18S1270, D19S253, D20S161, and D21S1437) which are not included in the standard sets of forensic loci. The markers were selected according to the complexity of the polymorphic region: Of the 15 investigated loci, 7 loci showed a simple repeat structure (D9S304, D10S2325, D14S608, D16S3253, D18S1270, D19S253, and D21S1437), 3 loci (D7S1517, D12S391, and D20S161) consisted of compound repeat units, and 5 loci (D1S1656, D8S306, D8S639, D11S488, and D17S976) showed a more complex polymorphic region partly including different repeat blocks and incomplete repeat units, which resulted in a relatively high proportion of intermediate alleles. A population study on a sample of 270 unrelated persons from Austria was carried out. We did not observe significant deviations from Hardy-Weinberg expectations. The combined probability of exclusion for the 15 loci was 0.99999998. In combination with the conventional set of STR markers included in commercially available kits (no linkage was observed between these 15 loci and the Powerplex 16 System loci), these markers are approved as highly discriminating forensic tools, also suitable for the analysis of difficult paternity and kinship constellations.

The molecular methods that are presently being used for studying phylogenetics, phylogeography and population genetics can also be applied to study bird migration. They are powerful and can supplement the information obtained from ringing, telemetry, morphometrics, ringing, radar tracking and isotope analysis. This short review describes the principles, scopes and limitations DNA methods and DNA markers that are relevant for migration research, such as DNA sequences, short tandem repeats (microsatellites), single nucleotide polymorphisms, amplified fragment length polymorphism, inter simple sequence repeats and molecular sexing.

Cross-contamination between cultured cell lines can result in the generation of erroneous scientific data. Hence, it is very important to eliminate cell lines that are of an origin different from that being claimed. Inter-species contamination can be detected by various established methods, such as karyotype and isozyme analyses. However, it has been impossible to detect intraspecies cross-contamination prior to the development of technology to detect differences between cell lines at the molecular level. Recently, profiling of short tandem repeat (STR) polymorphisms has been established as a method for the analyses of gene polymorphism. Gene profiling by STR polymorphism (STR profiling) is a simple and reliable method to identify individual cell lines. Each human cell line currently provided by the Cell Engineering Division of the RIKEN BioResource Center was analyzed by STR profiling to authenticate its identity. We found that more than 10 human cell lines out of approximately 400 were in fact identical to a different cell line deposited in the collection, and therefore had been misidentified. We conclude that STR profiling is a useful and powerful method for eliminating cell lines that have been misidentified by cross-contamination or by other causes. Hence, STR profiling of human cell lines used in published research will likely be a prerequisite for publication in the future, so that the problem of misidentification of cell lines can be eliminated.

The human phosphoglycerate kinase (PGK1) gene is located within Xqll-Xql3 and is closely linked to the androgen receptor gene within a region implicated in a number of X-chromosome-linked urologic disorders. A polymorphism of a TATC short tandem repeat (STR) is present downstream from the PGK1 3' nuclease-sensitive site. We present the PGK1 flanking STR sequence and population genetic data for 190 Japanese males and 83 Japanese females. Ten STR alleles and 29 genotypes were identified in the population. Five alleles--*10, *11, *12, *13, and *14--were common in the Japanese with frequencies greater than 10%. No significant deviations from Hardy-Weinberg equilibrium were established. The power of discrimination was 0.993 for females and 0.819 for males; heterozygosity was 0.759 for females; and the polymorphic information content was 0.936. These data indicate that this STR locus shows a high degree of polymorphism in this Japanese population and may prove to be a useful genetic marker in forensic medicine, in determining the clonality of neoplasms, and potentially in studying predisposition to prostate cancer and other urologic diseases.

Molecular technique with STRs can rapidly diagnose aneuploidy. In order to improve its fidelity, we developed a novel STR-based strategy for fast diagnosis of trisomy 21 and constructed a multimarker diagnostic system according to it. The system is based on nine STRs, of which two were previously known and seven were newly identified from the genomic sequence of the long arm of chromosome 21. They were confirmed to be highly polymorphic in the Chinese population by PCR amplification and gel electrophoresis. The combination of nine STR markers, when applied to DNA from 102 Chinese individuals with normal karyotype, did not yield any false-positives, and clearly revealed three different alleles in DNA from 15 out of 18 trisomy 21 patients. The results show that our new strategy can provide an alternative molecular technique for the rapid detection of aneuploidy.

A simple and rapid detection of short tandem repeat (STR) markers was studied as a screening test for individual identification of cattle. DNAs were extracted from eight commercial beef samples by a proteinase K-boil method followed by purification with 2-propanol precipitation. Five STR markers, known to be highly polymorphic, were amplified by PCR and analyzed both by a conventional sequencing analysis (SEQ) and by a proposed microchip electrophoresis (MEP). Every marker revealed high polymorphism, such as 5-9 alleles in SEQ analysis, and 4-6 alleles in MEP analysis. This simple and rapid MEP analysis is expected to be an effective screening tool with use of confirmatory SEQ analysis.

A forensic genotyping panel of 11 tetranucleotide STR loci from the domestic cat was characterized and evaluated for genetic individualization of cat tissues. We first examined 49 candidate STR loci and their frequency assessment in domestic cat populations. The STR loci (3–4 base pair repeat motifs), mapped in the cat genome relative to 579 coding loci and 255 STR loci, are well distributed across the 18 feline autosomes. All loci exhibit Mendelian inheritance in a multi-generation pedigree. Eleven loci that were unlinked and were highly heterozygous in cat breeds were selected for a forensic panel. Heterozygosity values obtained for the independent loci, ranged from 0.60–0.82, while the average cat breed heterozygosity obtained for the 11 locus panel was 0.71 (range of 0.57–0.83). A small sample set of outbred domestic cats displayed a heterozygosity of 0.86 for the 11 locus panel. The power of discrimination of the panel is moderate to high in the cat breeds examined, with an average Pm of 3.7E-06. The panel shows good potential for genetic individualization within outbred domestic cats with a Pm of 5.31E-08. A multiplex protocol, designed for the co-amplification of the 11 loci and a gender-identifying locus, is species specific and robust, generating a product profile with as little as 0.125 nanograms of genomic DNA.