Amelogenin Locus Research Articles

Detection of aneuploidies in spontaneous abortions by quantitative fluorescent PCR with short tandem repeat markers: a retrospective study.

Approximately 10-15% of all pregnancies end in spontaneous abortions. Many factors can lead to embryonic loss; however, it has been well established that over 50% of all miscarriages result from chromosomal abnormalities, primarily aneuploidies (>96%). Identifying the cause of miscarriage can significantly reduce the psychological stress in women, and enable better genetic counseling for a future pregnancy. Quantitative fluorescent polymerase chain reaction (QF-PCR) has been previously used in the study of chromosomal abnormalities. In this retrospective study, the frequency of aneuploidy in samples of 130 miscarriages undergone by patients (age average: 34.1 ± 4.6 years) at our institution was determined by QF-PCR using short tandem repeat markers. The gender of the miscarriage cases was determined by amplifying the amelogenin locus (70 males and 60 females). Seventy-one of these cases (54.6%) presented aneuploidies such as trisomy, monosomy, triploidy, and double trisomy. Trisomy 22 was the most common aneuploidy (present in 14 cases), followed by trisomy 15, trisomy 16, and monosomy X. We also observed monosomy at chromosomes X and 21 and a case with multiple aneuploidies at chromosomes 16 and 22. The most common aneuploidies associated with miscarriages were detected by QF-PCR; therefore, we concluded that QF-PCR is a rapid and reliable method for the detection of aneuploidy, and can be used as an accessory to the widely used karyotype analysis.

Genetic polymorphisms of 22 autosomal STR loci in Chinese Han population

Microreader™ 23sp ID system was a new STR multiplex system developed for forensic application, but there was a lack of population data in the Chinese Han population. This kit contained 21 non-CODIS STR loci (D6S477, D18S535, D19S253, D15S659, D11S2368, D20S470, D1S1656, D22-GATA198B05, D7S3048, D8S1132, D4S2366, D21S1270, D13S325, D9S925, D3S3045, D14S608, D10S1435, D12S391, D2S1338, D17S1290, D5S2500), one CODIS STR locus (D16S539) and the amelogenin locus. In this study, a population sample in Chengdu Han population was analyzed with the kit. Forensic genetic parameters and probability values of the Hardy–Weinberg equilibrium (HWE) were calculated with software PowerStats v1.2 and Arlequin v3.5. Allele frequencies of the 22 STR loci and further forensic genetic parameters were obtained. The results suggested that Microreader™ 23sp ID system can provide informative polymorphic data for identification and parentage testing in Chinese Han population.

Ovine fetal sex determination using circulating cell-free fetal DNA (ccffDNA) and cervical mucous secretions

Abstract Objective To use PCR to investigate the presence of fetal SRY gene in the ovine cervical secretions and maternal blood plasma, and to assess predict fetal sex at different times of gestation in the ewe. Methods Fetal DNA was isolated from blood plasma and cervical secretions of 32 pregnant ewes during the 6 to 21 week of gestation. Overall, 15 male and 17 female fetuses were included in this study. After DNA extraction, the PCR amplified a 280 bp fragment from the X-chromosome and a 217 bp fragment from the Y-chromosome based on a sex-related polymorphism in the amelogenin locus. Results The presence of fetal Y-chromosome was confirmed in 11 out of 15 cervical mucus and 12 out of 15 blood plasma samples collected from sheep with male fetuses. The sensitivity and specificity of tests were 70% with false negative results. Conclusion This is the first report on validating the presence of fetal DNA material in the ovine cervical mucus and its potential usefulness for fetal sexing.

Generating Human DNA Profile(s) from Cell Phones for Forensic Investigation

The goals of this study were to investigate whether sufficient amount of human DNA can be recovered from a cell phone and if the identity of the single and/or multiple user(s) can be established by generating genetic profile(s). Cell phones were used to collect human DNA. Two Buccal swabs were used to collect Buccal cells as a DNA reference samples. Four soaked sterile cotton swabs were used to collect biological materials from each user’s cell phone. Sufficient quantity and quality of human genomic DNA was obtained from the cell phones using Quantifiler® Human DNA Quantitation Kit. More human DNA was collected from volunteers’ Buccal swabs (=74.56 ng) than from the surface of their cell phones (=0.23 ng). One nanogram (1 ng) of template DNA was used for buccal swabs and cell phones swabs, if available. However, when the DNA recovered from cell phone swabs was 0.00 to 500 pg, 10 μL of template DNA was used. In addition, the number of PCR cycles was increased from 28 to 32 in anticipation of Low Copy Number DNA. Genetic profiles were developed from the DNA on the cell phones and were compared with the reference DNA profiles from the buccal cells of the cell phone owners. Full Short Tandem Repeats (STR) DNA profiles for all 15 STR loci plus Amelogenin locus were typed for 36 Buccal swabs, reference DNA of cell phone owners. Complete STR profiles were generated from 33% (N=36) cell phones and were matched participants’. In addition, 28% of cell phones had partial DNA profiles matched with the cell phone owners. While, 33% of the cell phones had unknown partial or complete profiles. Four of the unknown partial profiles had more than two alleles at the STR loci indicating multiple unknown cell phone users. The Y chromosome was detected at the Amelogenin locus from the DNA profiles generated from two females’ cell phones identifying unknown male contributor(s). Our study demonstrates that DNA collected from the cell phones can be used as reliable physical evidence in forensic investigations.

Laser Capture and Single Cell Genotyping from Frozen Tissue Sections.

There is an increasing requirement for genetic analysis of individual cells from tissue sections. This is particularly the case for analysis of tumor cells but is also a requirement for analysis of cells in pancreas from individuals with type 1 diabetes where there is evidence of viral infection or in the analysis of chimerism in pancreas; either post-transplant or as a result of feto-maternal cell transfer.This protocol describes a strategy to isolate cells using laser microdissection and to run a 17plex PCR to discriminate between cells of haplo-identical origin (i.e., fetal and maternal cells) in pancreas tissue but other robust DNA tests could be used. In short, snap-frozen tissues are cryo-sectioned and mounted onto membrane-coated slides. Target cells are harvested from the tissue sections by laser microdissection and pressure catapulting (LMPC) prior to DNA profiling. This is based on amplification of highly repetitive yet stably inherited loci (short tandem repeats, STR) as well as the amelogenin locus for sex determination and separation of PCR products by capillary electrophoresis.

Genetic diversity between two Igbo men from Owerri senatorial province as determined by autosomal short tandem repeats, Y-chromosomal short tandem repeats and mitochondrial DNA typing methods

Background: Human identification has recently been optimized following the completion of human genome sequence, by using DNA markers that exhibit the highest possible variation. However, in developing countries such as Nigeria, the application of DNA typing for identification of human subjects either for forensic or medical purposes is inadequate due to the absence of national forensic DNA laboratories and lack of the legislative framework. Materials and Methods: In this study, two male subjects of Igbo origin provided their blood, hair and buccal samples for DNA analysis. DNA was extracted, purified, quantified with human quantifiler™ polymerase chain reaction reaction mix. Hyper-variable segment 1 of the D-loop mitochondrial DNA (mtDNA HVS-1) was amplified, purified and fragments sequenced and analyzed with ABI Genetic Analyzer. A multiplex AmpFlSTR Identifiler kit amplified 15 STR plus amelogenin loci of the nuclear DNA and 16 STR of the Y-chromosome. GeneMapper ID software version 3.2 was used for the analysis of autosomal and Y-chromosome AmpFlSTR. Results: Result show that the mtDNA lineage of UMBACK subject belongs to L3e2b while ELAMBIA is assigned to L3f1b1 haplogroup. Based on the allelic frequency database, both subjects displayed uniqueness in random match probability for the autosomal allelic short-tandem repeat (STR). Based upon a mutation rate of 0.003 for Y-DNA STR markers, the two individuals most likely shared a common paternal ancestor 96 generations ago. Both subjects were assigned to E1b1a haplogroup with a 100% probability, which is consistent with the haplogroup associated with Igbo people in Nigeria. Conclusion: As expected, well-established forensic genetic tools comprising of mtDNA, autosomal and Y-chromsomomal STR typing methods were all found to distinguish two selected Nigerian Igbo individuals with a very high power of discrimination.

Developmental validation of the AGCU 21+1 STR kit: a novel multiplex assay for forensic application.

In this study, we describe the developmental validation assay performed on a novel designed STR multiplex system, AGCU 21+1 STR kit. This kit contains a sex-determining locus amelogenin and 21 noncombined DNA index system STR loci, that are, D6S474, D12ATA63, D22S1045, D10S1248, D1S1677, D11S4463, D1S1627, D3S4529, D2S441, D6S1017, D4S2408, D19S433, D17S1301, D1GATA113, D18S853, D20S482, D14S1434, D9S1122, D2S1776, D10S1435, and D5S2500. The 21+1 kit was validated by a series of tests including optimized PCR conditions, sensitivity, precision and accuracy, stutter ratio, DNA mixture, inhibitors, and species specificity according to the revised validation guidelines issued by the Scientific Working Group on DNA Analysis Methods (SWGDAM). Our results in this study show that the kit is a useful tool for forensic application.

Concordance study between the ParaDNA® Intelligence Test, a Rapid DNA profiling assay, and a conventional STR typing kit (AmpFlSTR® SGM Plus®)

The ParaDNA® Intelligence Test enables STR profiling directly from human biological samples and evidence items collected from crime scene in 75min. Designed for non-expert use this system allows DNA information to be available to investigators before it would typically be available from a laboratory. The ParaDNA Intelligence Test system amplifies D3S1358, D8S119, D16S539, D18S1358 and TH01 STR loci and the gender typing locus amelogenin and detects the alleles present with HyBeacon® probes. Individual DNA samples from 381 UK Caucasian individuals were analysed using AmpFlSTR® SGM Plus® and the ParaDNA Intelligence Test with the derived STR profiles compared. Here we describe the high level of concordance demonstrated between the two systems and discuss this with reference to allele frequencies and the discriminatory power offered by the ParaDNA Intelligence Test.

A Pilot Study of the Hair-Trapping Method in Asiatic Black Bears (Ursus thibetanus): Determination of Optimal Survey Period for Estimating Population Size

In order to establish methodology for population estimation of Asiatic black bears using the hair-trapping method, hair-trapping devices were located within a study area, and basic data were collected to determine the optimal survey period for hair sampling. Bear hairs collected were classified as three types (guard hair; G, underfur; U, and intermediate hair; I) depending on hair-bulb thickness. After DNA extraction, six microsatellite loci and amelogenin locus were amplified in order to identify individual bears and sex, respectively. The number of hairs collected by hair-trapping devices decreased dramatically in late August, while those that had lost part of the hair bulb increased after September. The success rate of genetic analysis was over 90% prior to the month of July and rapidly decreased in August. Based on the results of the generalized linear model, it was determined that sampling session had the most significant impact on the success rate of genetic analysis of all the explanatory variables examined. Higher rates of U-type hairs within samples used in DNA extraction resulted in lower success rates of genetic analysis. It was concluded that the optimal survey period for estimating population size using the hair-trapping method was between June and early August.

Amelogenin test abnormalities revealed in Belarusian population during forensic DNA analysis

Study of gender markers is a part of routine forensic genetic examination of crime scene and reference samples, paternity testing and personal identification. Amelogenin locus as a gender marker is included in majority of forensic STR kits of different manufacturers. In current study we report 11 cases of amelogenin abnormalities identified in males of Belarusian origin: 9 cases of AMELY dropout and 2 cases of AMELX dropout. Cases were obtained from forensic casework (n=9) and paternity testing (n=2) groups. In 4 out of 9 AMELY-negative cases deletion of AMELY was associated with the loss of DYS458 marker. In addition, we identified 3 males with SRY-positive XX male syndrome. Deletion of the long arm of the Y-chromosome was detected in two XX males. Loss of the major part of the Y-chromosome was identified in the third XX male. The presence of two X-chromosomes in XX males was confirmed with the use of Mentype® Argus X-8 PCR Amplification Kit. AMELY null allele observed in 2 out of 9 cases with AMELY dropout can be caused by mutation in the primer-binding site of AMELY allele. Primer-binding site mutations of AMELX can result in AMELX dropout identified in 2 cases with amplification failure of AMELX. Our study represents the first report and molecular genetic investigation of amelogenin abnormalities in the Belarusian population.

Phylogenetic analysis of two haploid markers of 500-years-old human remains found in a central region of Korea

To understand the genetic history of maternal/paternal lineages of Koreans, we analyzed two haploid markers, mitochondrial DNA (mtDNA), and Y-chromosomal variations, in 25 human remains (dated at about 400–600 years old) excavated from a central region of Korea (Yangchon cemetery of Gimpo-si, Gyeonggi-do). MtDNA control region (HVS-I/II) sequences of 19 ancient human samples from a total of 25 remains were successfully determined by sequencing after PCR-cloning and direct sequencing techniques. Among the 25 remains, 12 individuals were found to be males determined by the amelogenin locus using PCR amplification. We found that the vicinal burial of the remains seemed to be related matrilineally or patrilineally. The most common mtDNA haplogroups were found to be D4a (5/19), followed by D4 (3/19), F1bde (3/19), D4c (2/19), D4g2a (1/19), B5b (1/19), F (1/19), F1a1 (1/19), G4 (1/19), and N9a (1/19), which are prevalent in the Northeast and Southeast Asians, including modern Koreans. On the paternal side, there are three dominant Y chromosome haplogroups C (41.7 %), O3 (25 %), and Y* (33.3 %) in total male samples. The phylogenetic analysis of the mtDNA HVS-I sequence variation revealed both the overall similarity to other northeastern populations, and also a larger genetic contribution from southeastern populations. Thus, these results are consistent with previous reports that the peopling of Korea is likely to have involved multiple sources. Larger sample sizes and additional genetic markers will be necessary to fully understand the population structure and the genetic history of the Koreans.

Construction of a library of cloned short tandem repeat (STR) alleles as universal templates for allelic ladder preparation.

Short tandem repeat (STR) genotyping methods are widely used for human identity testing applications, including forensic DNA analysis. Samples of DNA containing the length-variant STR alleles are typically separated and genotyped by comparison to an allelic ladder. Here, we describe a newly devised library of cloned STR alleles. The library covers alleles X and Y for the sex-determining locus Amelogenin and 259 other alleles for 22 autosomal STR loci (TPOX, D3S1358, FGA, D5S818, CSF1PO, D7S820, D8S1179, TH01, vWA, D13S317, D16S539, D18S51, D21S11, D2S1338, D6S1043, D12S391, Penta E, D19S433, D11S4463, D17S974, D3S4529 and D12ATA63). New primers were designed for all these loci to construct recombinant plasmids so that the library retains core repeat elements of STR as well as 5'- and 3'-flanking sequences of ∼500 base pairs. Since amplicons of commercial STR genotyping kits and systems developed in laboratories are usually distributed from 50 to <500 base pairs, this library could provide universal templates for allelic ladder preparation. We prepared three different sets of allelic ladders for this locus TH01 and an updated version of an allelic ladder for the DNATyper(®)19 multiplex system using these plasmids to confirm the suitability of the library as a good source for allelic ladder preparation. Importantly, the authenticity of each construct was confirmed by bidirectional nucleotide sequencing and we report the repeat structures of the 259 STR alleles. The sequencing results showed all repeat structures we obtained for TPOX, CSF1PO, D7S820, TH01, D16S539, D18S51 and Penta E were the same as reported. However, we identified 102 unreported repeat structures from the other 15 STR loci, supplementing our current knowledge of repeat structures and leading to further understanding of these widely used loci.

Developmental validation of a forensic rapid DNA-STR kit: Expressmarker 16

DNA-STR analysis is widely used in the forensic science field and has important requirements on the analysis time to obtain faster inspections. The developed forensic STR kit, referred to as Expressmarker 16 (EX16), could shorten the amplification time to a minimum of 35min. It enables 16 STR loci to be co-detected, including 13 CODIS loci, D2S1338, D6S1043 and Amelogenin loci. The kit is validated by a series of tests formed by DNA mixtures, stutter ratios, optimized PCR protocols based on annealing temperature research, species specificities, inhibitors, sensitivity, and parallel tests according to FBI QAS (2009/2011) (QAS, 2009; SWGDAM, 2010). The results demonstrated that EX16 was a useful tool for rapid criminal investigation.

Comparing six commercial autosomal STR kits in a large Dutch population sample

Regularly, STR results obtained with different PCR amplification kits are compared, for instance with old cases, when revisiting cold cases or when addressing cross-border crimes. It is known that differences in primer design for the same loci in different kits may give rise to null alleles or shifted alleles. In this study, the genotyping results of 2085 Dutch male samples were compared for six autosomal STR kits (Promega's PowerPlex(®) 16, ESX-16 and ESI-17 Systems, Qiagen's Investigator(®) ESSplex Kit and Applied Biosystems' AmpFlSTR(®) Identifiler and NGM PCR Amplification Kits). A total of 19 discordant autosomal genotyping results were obtained that were examined by sequence analysis using Roche-454 next generation sequencing and/or Sanger sequencing. A further 25 discordances were found and sequenced for the Amelogenin locus. The 24 samples showing the same primer binding site mutation at the Amelogenin locus were subjected to X-STR analysis in order to assess whether they could share a common origin, which appeared not to be the case. Based on the sequencing results, we set the final genotypes and determined the allele frequencies of 23 autosomal STRs for the Dutch reference database.

Evaluation of genetic parameters of 22 autosomal STR loci (PowerPlex® Fusion System) in a population sample from Northern Italy

The PowerPlex® Fusion System (Promega, Madison, WI) is a short tandem repeat (STR) multiplex that allows co-amplification of 22 autosomal STRs, including the CODIS core and the European Standard Set loci, plus amelogenin for gender determination and DYS391 male specific marker included in order to avoid errors in gender assignment when null Y-alleles or deletions of the Y-chromosome short arm involve the amelogenin locus. Allele frequencies and forensic efficiency parameters were estimated in a population sample of 303 unrelated healthy individuals living in Northern Italy. No significant deviations from Hardy-Weinberg expectations were observed after applying Bonferroni's correction for multiple testing. The combined power of discrimination was 0.999999999999 and the combined power of exclusion was 0.9999956. A rare 28 allele at locus D12S391 was observed, while one tri-allelic pattern at Penta E locus was detected. Population differentiation test revealed significant genetic diversity between our population sample and other European populations considered. The results showed that the PowerPlex® Fusion System is one of the most informative kit available in forensic genetics and may prove useful in both human identification and kinship analysis.

A 21‐Locus Autosomal SNP Multiplex and its Application in Forensic Science

To develop a cost-effective technique for single-nucleotide polymorphism (SNP) genotyping and improve the efficiency to analyze degraded DNA, we have established a novel multiplex system including 21-locus autosomal SNPs and amelogenin locus, which was based on allele-specific amplification (ASA) and universal reporter primers (URP). The target amplicons for each of the 21 SNPs arranged from 63 base pair (bp) to 192bp. The system was tested in 539 samples from three ethnic groups (Han, Mongolian, and Zhuang population) in China, and the total power of discrimination (TPD) and cumulative probability of exclusion (CPE) were more than 0.99999999 and 0.98, respectively. The system was further validated with forensic samples and full profiles could be achieved from degraded DNA and 63 case-type samples. In summary, the multiplex system offers an effective technique for individual identification of forensic samples and is much more efficient in the analysis of degraded DNA compared with standard STR typing.

Genotyping of 38 insertion/deletion polymorphisms for human identification using universal fluorescent PCR

Short insertion/deletion (Indel) polymorphisms of approximately 2–6 bp are useful as biallelic markers for forensic analysis, and the application of Indel genotyping as a supplementary tool would improve human identification accuracy. We examined the allele frequencies of 37 autosomal Indels in the Japanese population and developed a novel dual-color genotyping method for human identification on the basis of universal fluorescent PCR, including the sex-typing amelogenin locus. Target genomic fragment sizes for 38 Indels were 49–143 bp. We analyzed these Indels in 100 Japanese individuals using the M13(-47) sequence as a universal primer. For dual-color genotyping, we designed a novel universal primer with high amplification efficiency and specificity. Using FAM-labeled M13(-47) and HEX-labeled modified M13(-47) primers, fluorescent signals at all loci were clearly distinguished in two independent multiplex PCRs. Average minor allele frequency was 0.39, and accumulated matching probability was 2.12 × 10−15. Complete profiles were successfully amplified with as little as 0.25 ng of DNA. This method provides robust, sensitive, and cost-effective genotyping for human identification.

I-DNASE21 system: Development and SWGDAM validation of a new STR 21-plex reaction

I-DNASE21 is a new STR multiplex system that amplifies 21 STR autosomal loci, plus the amelogenin locus in one reaction. This system has been designed to analyze all the STR loci included in the Combined DNA Index System (CODIS), Interpol Standard Set of Loci (ISSL), Extended European Standard Set (ESS-Extended), UK National Criminal Intelligence DNA Database (NDNAD) and German Core loci (GCL). This manuscript presents the validation of the I-DNASE21 system according to the revised guidelines issued by the Scientific Working Group on DNA Analysis Methods (SWGDAM). The results of this validation, added to the extremely high discriminatory power showed, suggest that I-DNASE21 could be a potentially helpful tool for identification and kinship determination even in complex paternity cases.

Fully integrated, fully automated generation of short tandem repeat profiles

BackgroundThe generation of short tandem repeat profiles, also referred to as ‘DNA typing,’ is not currently performed outside the laboratory because the process requires highly skilled technical operators and a controlled laboratory environment and infrastructure with several specialized instruments. The goal of this work was to develop a fully integrated system for the automated generation of short tandem repeat profiles from buccal swab samples, to improve forensic laboratory process flow as well as to enable short tandem repeat profile generation to be performed in police stations and in field-forward military, intelligence, and homeland security settings.ResultsAn integrated system was developed consisting of an injection-molded microfluidic BioChipSet cassette, a ruggedized instrument, and expert system software. For each of five buccal swabs, the system purifies DNA using guanidinium-based lysis and silica binding, amplifies 15 short tandem repeat loci and the amelogenin locus, electrophoretically separates the resulting amplicons, and generates a profile. No operator processing of the samples is required, and the time from swab insertion to profile generation is 84 minutes. All required reagents are contained within the BioChipSet cassette; these consist of a lyophilized polymerase chain reaction mix and liquids for purification and electrophoretic separation.Profiles obtained from fully automated runs demonstrate that the integrated system generates concordant short tandem repeat profiles. The system exhibits single-base resolution from 100 to greater than 500 bases, with inter-run precision with a standard deviation of ±0.05 - 0.10 bases for most alleles. The reagents are stable for at least 6 months at 22°C, and the instrument has been designed and tested to Military Standard 810F for shock and vibration ruggedization. A nontechnical user can operate the system within or outside the laboratory.ConclusionsThe integrated system represents the first generation of a turnkey approach to short tandem repeat profiling and has the potential for use in both the field (for example, police booking stations, the battlefield, borders and ports) and the forensic laboratory.

A 27-Locus STR Assay to Meet All United States and European Law Enforcement Agency Standards,

Different national and international agencies have selected specific STR sets for forensic database use. To enhance database comparison across national and international borders, a 27-locus multiplex system was developed comprising all 15 STR loci of the European standard set, the current 13 STR loci of the CODIS core, the proposed 22 STR loci of the expanded CODIS core, 4 additional commonly used STR loci, and the amelogenin locus. Development required iterative primer design to resolve primer-related artifacts, amplicon sizing, and locus-to-locus balance issues. The 19.5-min assay incorporated newly developed six-dye chemistry analyzed using a novel microfluidic electrophoresis instrument capable of simultaneous detection and discrimination of 8 or more fluorescent dyes. The 27-locus multiplex offers the potential for a new international STR standard permitting laboratories in any jurisdiction to use a single reaction to determine profiles for loci they typically generate plus an expanded common STR profiling set of global interest.