In the field, commercial ystr kits assist forensic biologists detect and characterize dna from males in mixed stains with dna from females. The stutter analysis of the 26plex typing system was made according to the results obtained from the genotyping of 200 male dna samples 1 ng with the 26plex typing system on ab 3 genetic analyzer. An ultrahigh discrimination y chromosome short tandem repeat. Improved ystr analysis of degraded dna using reduced size. Training at our location, or our mobile training team mtt blends classroom instruction, small group discussion and demonstrations with handson practical exercises so participants quickly gain exploitation. In the united states, autosomal str loci are now accepted as the system used for forensic purposes. Powerpoint slides for figures from forensic dna typing 2nd edition 181 slides, 8. A short tandem repeat str is a microsatellite, which is polymorphic in. Application of y str typing in solving a forensic case. Utility of the ystr typing systems yplex 6 and yplex 5 in forensic casework and 11 ystr haplotype database for three major population groups in the united states, journal of forensic sciences 2004 49. Routine ystr typing in forensic casework researchgate.
Forensic dna typing, second edition, is the only book available that specifically covers detailed information on mitochondrial dna and the y chromosome. Since the system was designed specifically to augment the european y chromosome typing communitys minimal haplotype ystr set mhl for forensic casework, it contains a novel constellation of. Results were compared with those from the ampflstr yfiler pcr amplification kit. Request pdf ystr typing in forensic analysis we reinvestigated 20 cases of rapesexual maltreatment from the years 20002001 i. Swgdam guidelines for str enhanced detection methods. Forensic applications of y chromosome strs and snps principal investigators. The primary application of ystrs in forensics is the analysis of sexual assault samples 8,9. During the 1980s, most digital forensic investigations consisted of live analysis, examining digital media directly using nonspecialist tools. Basic priniciples for estimating the rarity of ystr. Ystr typing in the identification of genetic profile of the semen. Courts have already widely accepted str typing, instrumentation, and software for analysis ystr markers just have different pcr primers acceptance of statistical reports using the counting methoddue to previous experience with mtdna scenarios where ystrs can aid forensic casework sexual assaults by vasectomized or azoospermic.
Ychromosome short tandem repeat ystr analysis and typing. In forensic casework, y chromosome short tandem repeat markers ystrs are often used to identify a male donor dna profile in the presence of excess quantities of female dna, such as is found in many sexual assault investigations. There are several additional benefits of ystr analysis in forensic casework. The autodimer software was developed to rapidly screen previously selected pcr primers for primerdimer and hairpin interactions in short dna oligomers forensic. Forensic approach to analyzing rape cases forensic science. Request pdf routine y str typing in forensic casework in the field of molecular diagnosis, forensic casework analysis is one of the most demanding investigations, due to its social impact. Forensic science training national forensic science. This type of dna testing can be invaluable in cases where male dna is present on evidence but cannot be detected using traditional str testing. Application of y str typing in solving a forensic case amany a abdulhakimmoussa 1, mohammed a al ramadi, adel ma elberry1 and fadwa a elroby2 1egyptian forensic medicolegal authority, egypt 2department of forensic medicine and clinical toxicology, beni suef university, egypt case presentation figure 1. The most common type of dna profiling today for criminal cases and other types of forensic uses is called str short tandem repeat analysis. This document is not intended to invalidate any forensic.
The methodology was developed in parallel with the autosomal str analysis for human identification purposes and evaluated in a very similar way for forensic analysis. Y chromosome strs are demonstrating value in the forensic identification of male dna from sexual assault cases. A distinguishing tool for exclusion in a casework of sexual assault suminder kaur 1, monica lamba 1 and ritika gupta 2 1 regional forensic science laboratory, dna fingerprinting unit, biology division, new delhi110021, india. If, for example, dna evidence of sexual activity on a female homicide victim is detected using autosomal str analysis, y str analysis can be applied to corroborate these findings using touch. Forensic biology protocols for forensic str typing genemapper id default table and plot settings date effective 06202016 approved by nuclear dna technical leader page 1 of 70 controlled versions of department of forensic biology manuals only exist in the forensic biology qualtrax software. Ystr analysis allows for the facile determination of the number of male contributors in mixtures. Table s4 shows the detected allelic frequencies, gene diversity and forensic parameters of the 26 ystrs. However, in many forensic cases, dna samples are highly degraded.
Why should forensic labs use ystr analysis in sexual assault cases. A number of recent improvements have provided contemporary forensic investigations with a variety of tools to improve the analysis of mixed dna samples in criminal investigations, producing notable improvements in the analysis. Shortly after the characterization and evaluation of the. The analysis of str loci has become a routine procedure in forensic laboratories 1,2. The analysis of short tandem repeat str markers located on the y. Jan 27, 2009 the analysis of regular str dna has become the gold standard of identification in forensic casework. We have been on the forefront of forensic analysis. Fragment sizes were determined automatically using the genescan analysis software v 3. Ychromosome strs are demonstrating value in the forensic identification of male dna from sexual assault cases. Forensic analytical crime lab dna evidence forensic. A 21plex system of strs integrated with ystr dys391 and. A 21plex system of strs integrated with ystr dys391 and abo typing for forensic dna analysis le wang national engineering laboratory for forensic science and mps key laboratory of forensic genetics, institute of forensic. Forensic dna typing by capillary electrophoresis using the.
Rapid ystr typing for both screening samples and identification purposes was. Swgdam validation guidelines for forensic dna analysis methods. Forensic biology protocols for forensic str typing approval form. Thus, application of y chromosomal strs to forensic casework might be useful and more informative than autosomal str typing plus amelogenin alone, especially if there are dna mixtures from two or more male persons or if the male suspect is unknown and only mixed dna from victim and suspect is available. This type of dna testing can be invaluable in cases where male dna is present on evidence but cannot be detected using traditional str testing methods. Forensic characteristics and genetic affinity analyses of. Kinship testing based on snps using microarray system. Forensic applications of y chromosome strs and snps. The forensic biology team at nms labs recently conducted a. Ystr markers are useful when multiple males are involved in a sexual assault. Dec 26, 2019 forensic characteristics and phylogenetic analysis of both y. Evaluating profilerplus and mentype pcrs, only two or three loci, respectively, could be determined as being loci from the suspect.
Other applications for ystrs include tracing paternal lineages to aid in missing. Jenkins, the y chromosome as a tool for studying human evolution, curr. Current developments in forensic interpretation of mixed. Ystr analysis focuses on short tandem repeats strs found on the y chromosome, only carried by male individuals for forensic labs, the most common application of ystrs is in criminal cases such as sexual assault, where evidence samples are difficult to resolve with traditional autosomal str analysis. Short tandem repeats str and singlenucleotide polymorphisms snp on the y chromosome were typed in 311 unrelated men from four different ethnic groups italians from northern italy, albanians, africans from the maghreb region, and indopakistanis, using the ampflstr yfiler pcr amplification kit and the snapshot multiplex kit. A ystr profile may provide the evidentiary lead needed to supplement an investigation. Correctly typing all assigned samples for the loci included in the typing kit used in the forensic biology unit. Software developed by the nist forensicshuman identity project team. Basic priniciples for estimating the rarity of y str haplotypes derived from forensic evidence bruce budowle, jianye ge, and ranajit chakraborty introduction the y chromosome str loci are malespecific and thus typing of these genetic markers enable analysis of previously problematic forensic biological samples, such as. Sometimes, regular str will cause the masking effect if there is a very small quantity of male dna in the mixed sample.
Forensic dna typing has an important impact on the society by providing reliable evidence both for convicting the offenders and for exonerating the innocent suspects. Learn the basics of data analysis software, become familiar with the purpose of genescan and genotyper software, learn the. Why should forensic labs use y str analysis in sexual assault cases. It examines the science of current forensic dna typing methods by focusing on the biology, technology, and genetic interpretation of short tandem repeat str markers, which encompass the most common forensic dna analysis.
An ultrahigh discrimination y chromosome short tandem. Y str markers have become a valuable tool for forensic dna typing especially in male sibship analysis and sexual crime investigation. Ystrs represent a powerful method in the studies of human evolution as well as in everyday analysis in the forensic practice, when determining the kinship relations and paternity expertise, especially in. Request pdf routine ystr typing in forensic casework in the field of molecular diagnosis, forensic casework analysis is one of the most demanding investigations, due to its social impact. While many legal professionals may be well acquainted with the conventional autosomal short tandem repeat str analysis that is typically associated with forensic cases involving dna, some may be less familiar with the technique of ychromosome str analysis. Ystr markers have become a valuable tool for forensic dna typing especially in male sibship analysis and sexual crime investigation. Ystr analysis used the same scientific foundation as str analysis, but the dna fragments that are being targeted in this type of testing are found only on the ychromosome making this analysis specific to males only. Forensic approach to analyzing rape cases forensic. Y str is also used for nonsexual assault cases where mixed samples are collected from evidence. Kinship analysis comparison with paternity probabilities based on the result of 169 snp typing along with initial autosomal and ystr typing in two pairs discussion it has been reported that snps can offer extra discrimination power to relationship tests that routinely are done using str typing. Commercially available ystr multiplexes incorporating 1217 loci are currently used in forensic casework promegas powerplex y and applied biosystems.
Ystr marker duplication likely arises due to a ychromosome region duplication followed by a singlestep mutation in the ystr repeat region for either the original marker or the copy. Performing y str testing can help to identify all males who have contributed to the evidence. In many sexual assault cases, standard autosomal str typing does not yield a probative result due to large quantities of female dna and very little male dna. Str markers or y str haplotyping is a method used to detect and differentiate male dna. Other applications for y strs include tracing paternal lineages to aid in missing persons investigations and historical studies and to help link families through genetic genealogy. Fb analysis of forensic casework using pcrbased autosomal and y str analysis training manual issued by. John butler organized workshop on new autosomal and ystr loci and kits.
Multiplex str typing is used in forensic, paternity and. Thus, males in the same lineage will possess identical ystr haplotypes allowing for the determination of a missing persons male haplotype by typing male relatives. Swgdam guidelines for the collection and serological examination of biological evidence. We provide top instructors, a support team, and the forensic equipment and supplies to ensure an in depth, immersive training experience. Snp in the li and han ethnic groups from hainan island of china. The hapydive program was used to determine haplotype diversities. Application of y str typing in solving a forensic case amany a abdulhakimmoussa 1, mohammed a al ramadi, adel ma elberry1 and fadwa a elroby2 1egyptian forensic medicolegal authority, egypt 2department of forensic. Ystrs are taken specifically from the male y chromosome. Y chromosome short tandem repeat ystr analysis is a specific type of str test performed by the drl only in cases of malefemale dna mixtures or to trace male lineage across generations. Since y str typing is more widely used than y snp in forensic casework, it seems workable and convenient to use y str haplotype to predict the most likely haplogroup thus referring the geographic or ethnic origin of unknown samples, suggesting that the validation using snp analysis is appropriate when high accuracy is required. Even with commercially available y str kits, the poor. Employing y str analysis, we obtained three new haplotypes that were not found in the european y str data collection, which currently contains around 7000 haplotypes from 51 population samples. Ystr typing in the identification of genetic profile of.
If a large section of the ychromosome containing multiple ystr markers was duplicated, then it may be possible for these sets of ystr alleles to diverge through mutation over multiple generations. Thus, application of y chromosomal strs to forensic casework might be useful and more informative than autosomal str typing plus amelogenin alone, especially if there are dna mixtures from two or. Str markers or ystr haplotyping is a method used to detect and differentiate male dna. A forensic dna typing system needs to be able to work with. Given enough y strs, which scientists call loci, a y str profile can offer substantial power to discriminate between individuals, but this type of profile is certainly not as powerful as an autosomal str profile. Addendum to the swgdam interpretation guidelines for autosomal str typing by forensic dna testing laboratories to address next generation sequencing. Y chromosome str analysis in forensic practice 14 these 7 systems have been extensively validated both with respect to molecular properties sequence structure, chromosomal localization, mutation rate, etc. In the past 2 years commercial ystr kits were developed to enable forensic. They dont offer comprehensive ystr typing at the same time or in the same kit. The practical competency exam is used to ascertain the trainees technical skills and abilities. A ystr is a short tandem repeat str on the ychromosome. Y str analysis can also be used in conjunction with autosomal strs to strengthen the evidence in a criminal case. Recommendations of the swgdam ad hoc working group on genotyping results reported as likelihood ratios. Swgdam contamination prevention and detection guidelines for forensic dna laboratories.
Development and validation of a novel 29plex ystr typing. The current standard method in forensic dna analysis is str typing, which utilizes the. Forensic typing of short tandem repeat markers on the x. Dna evidence forensic biology fa crime lab hayward. There are numerous cases though where biological evidence exists but regular dna testing cant provide probative evidence or insufficient nuclear dna was obtained.
It examines the science of current forensic dna typing methods by focusing on the biology, technology, and genetic interpretation of short tandem repeat str markers, which encompass the most common forensic dna analysis methods used today. Paternity testing and forensic dna typing by multiplex str. Y str s represent a powerful method in the studies of human evolution as well as in everyday analysis in the forensic practice, when determining the kinship relations and paternity expertise, especially in cases where the possible biological father is dead. We have been on the forefront of forensic analysis from a single gene to the stateoftheart amplification of numerous strs. Published pcr primers ychromosome strs lowtemplate dna. Swgdam interpretation guidelines for y chromosome str testing. If three men are involved in such an attack the investigators would expect ystr analysis to show a maximum of.
Str data analysis and interpretation for forensic analysts this course provides information in three lessons. The scientific working group on dna analysis methods, known as swgdam, serves as a forum to discuss, share, and evaluate forensic biology methods, protocols, training, and research to enhance forensic biology services as well as provide recommendations to the fbi director on quality assurance standards for forensic dna analysis. For forensic labs, the most common application of ystrs is in criminal cases such. Higher throughput approaches for str typing will also. Sep 01, 2001 a nomenclature for yca ii which is compatible with the isfg guidelines for y str analysis 2003, 481485, in vol. Forensic typing of short tandem repeat markers on the x and y chromosomes. Dna ystr typing is an important tool to solve criminal cases. Ystr analysis focuses on short tandem repeats strs found on the y chromosome, only carried by male individuals for forensic labs, the most common application of ystrs is in criminal cases such as sexual assault, where evidence samples are difficult to resolve with traditional autosomal str analysis due to low amounts of male dna present in a high background of female dna. Jack ballantyne from the university of central florida explains that y str analysis can help in such cases and it is a mere extension of standard methodology that. It is often challenging to obtain pcr amplification products from forensic samples because either the dna in those samples is degraded, or mixed, such as in a sexual assault case. Ychromosome polymorphisms and ethnic group a combined str. Our forensic biology team has been conducting criminal and civil investigations since 1982 and has been conducting pcrbased dna evidence analysis over the past 25 years. Dec 26, 2019 forensic characteristics and genetic affinity analyses of xinjiang mongolian group using a novel six fluorescent dye. Finally, ystr analysis can provide additional discriminatory power when combined with often partial autosomal str profile results.
The primary focus will be on the chemistry, hardware, and software used with the abi prism 310 genetic analyzer from applied biosystems as it is the most widely used instrument today for str analysis. Jack ballantyne from the university of central florida explains that ystr analysis. The smaller size of str alleles make str markers better candidates for use in forensic applications, in which degraded dna is common. Forensic value of novel strs on the human y chromosome 6 1. Ystr typing in forensic analysis request pdf researchgate. All male relatives from the same line are expected to share the same ystr profile, making ystr testing. Str short tandem repeat data analysis and interpretation software. Ystrs are often used in forensics, paternity, and genealogical dna testing. Y str typing in forensic analysis 2003, 487490, in vol. In the 1990s, several freeware and other proprietary tools both hardware and software were created to allow investigations to take place without modifying media.
Ystr typing was attempted on 166 semen traces from 89 cases that failed to yield a detectable male autosomal profile following differential extraction. However, in many forensic cases, dna samples are highly degraded and environmental contaminants are commingled with specimen. A novel 29plex ystr typing system was designed for forensic application. In many sexual assault cases, standard autosomal str typing does not yield a. Swgdam recommendations for the efficient dna processing of sexual assault evidence kits. Swgdam ystr interpretation guidelines approved 010914 2 p a g e guidelines which are intended to make it reflective of the current state of forensic ystr typing. A distinguishing tool for exclusion in a casework of sexual assault suminder kaur 1, monica lamba 1 and ritika gupta 2 1 regional forensic science laboratory, dna. Applications of y str typing in forensic casework jiyoun chae, heeyeon park, jongkeun jung, mijung kim, jiwon choi, sangcheul shin, sikeun lim dna analysis section, forensic medicine department, southern office branch of national forensic service, 50 gumoro, mulgum, yangsan, kyungsangnamdo, korea. Development of a new 26plex ystrs typing system for. This first set of tools mainly focused on computer forensics. Short tandem repeat within the malespecific part of the human y chromosome ystr is an effective forensic tool in mixture identification, patrilineal relationship evaluation, and familial searches.
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