scholarly journals Could Rapidly Mutating Y-STRs be a Potential Forensic Tool in Discriminating Lebanese Monozygotic Twins?

2018 ◽  
Vol 2 (2) ◽  
pp. 35
Author(s):  
Paula Romanos ◽  
Jamilah Borjac
Keyword(s):  
Twin Pair ◽  
Monozygotic Twins ◽  
Dna Profile ◽  
Identifiler Plus ◽  
Lineage Markers ◽  
Dna Profiles ◽  
Short Tandem Repeat Markers ◽  
Genetic Analyzer ◽  
Y Haplotype ◽  
Short Tandem

Despite the high power of discrimination that characterizes the well identified 16 to 24 autosomal short tandem repeat markers, monozygotic twins differentiation is generally limited. Arising from a single fertilized egg, monozygotic twins share the same genotype therefore the same DNA profile. This situation imposes a challenge in forensics especially considering that lineage markers are in general less informative than autosomal ones. Although in some cases Y haplotype is considered a powerful investigative tool, it cannot distinguish males belonging to the same paternal lineage.  The use of rapidly mutating Y-STRs with mutation rate above 1x10-2 that were recently included in forensic casework is presumed helpful. Since science is always dynamic and each population has its own characteristics, we aim in this study to distinguish between Lebanese monozygotic male twins using rapidly mutating Y-STRs. For this purpose, fourteen unrelated pairs of male monozygotic twins were recruited. Participants filled in a well-designed questionnaire and signed an informed consent. DNA was extracted using PureLink Genomic DNA Mini kit, genotyped using the Identifiler Plus kit, and separated on 3500 Genetic Analyzer to confirm the monozygosity status. DNA samples underwent a second amplification using the Y Filer Plus kit. According to our results, all the Y Filer Plus DNA profiles showed complete match for each twin pair. By consequence, the use of rapidly mutating Y-STRs in this study did not improve discrimination.

Validity of the Zygosity Questionnaire and Characteristics of Zygosity-Misdiagnosed Twin Pairs in the Healthy Twin Study of Korea

2010 ◽  
Vol 13 (3) ◽  
pp. 223-230 ◽  
Author(s):  
Yun-Mi Song ◽  
Dong-Hun Lee ◽  
Mi Kyoung Lee ◽  
Kayoung Lee ◽  
Hee Jung Lee ◽  
...  
Keyword(s):  
Twin Study ◽  
Twin Pair ◽  
Correct Diagnosis ◽  
Striking Similarity ◽  
Genotype Information ◽  
Zygosity Questionnaire ◽  
Questionnaire Method ◽  
Short Tandem Repeat Markers ◽  
Mz Twins ◽  
Short Tandem

AbstractDetermining valid zygosity is a basic and important requirement in a twin study, because misdiagnosing zygosity leads to biased results. The Healthy Twin Study has collected data from adult like-sex twins and their families since 2005. In the study, a questionnaire to determine zygosity was developed comprising four questions; one concerning the degree of resemblance, and three concerning the degree of confusion by the resemblance. Among 2,761 individuals (624 twin pairs) of twin and their families, 406 pairs of twins (mean age 38.3, 63.5% women) with both questionnaire and genotype information were selected to examine the validity of the zygosity questionnaire using 16 short tandem repeat markers. We first determined individual zygosity including undetermined category, and then decided the zygosity of a twin pair using a decision tree. Sensitivity of questionnaire diagnosis was 98.8% for monozygotic (MZ) and 88.9% for dizygotic (DZ) twins, and positive predictive value was 97.2% for MZ and 95.0% for DZ. When we compared correctly and wrongly diagnosed twin pairs, misdiagnosed DZ twins (nine pairs) showed striking similarity in stature or obesity even exceeding that of true MZ twins. Our finding suggests that a parsimonious questionnaire method of diagnosing the zygosity will be useful, and adding physical or physiological measurements to a questionnaire of zygosity diagnosis will either confound the correct diagnosis or reduce the efficiency of the study compared with using questionnaire alone or with introducing genotyping.

scholarly journals Family relation and STR-DNA matching using fuzzy inference

2019 ◽  
Vol 9 (2) ◽  
pp. 1335
Author(s):  
Maria Susan Anggreainy ◽  
M. Rahmat Widyanto ◽  
Belawati Widjaja ◽  
Nurtami Soedarsono ◽  
Putut Tjahjo Widodo
Keyword(s):  
Fuzzy System ◽  
Fuzzy Inference ◽  
Human Identity ◽  
Family Relation ◽  
Dna Profile ◽  
Fuzzy Similarity ◽  
Polymerase Chain ◽  
Mass Disasters ◽  
Dna Profiles ◽  
Short Tandem

Deoxyribose Nucleic Acid (DNA) are the basic elements that make up a whole section of an individual. The basic elements store information that is unique to each individual and will be passed down the generations. DNA also helps in identifying the father in paternity testing, locating missing person investigations, identifying victims in mass disasters. Identification of the victims has a problem if the comparison the father and mother no instance the victim’s parents have died or are very far away from where the victim. Therefore, it is necessary to try to identify Short Tandem Repeat (STR) Inference of live family such as sibling, grandfather/grandmother, uncle/aunt, cousin and nephew. In this paper, we performed a method to measure the similarity of human DNA profiles using fuzzy similarity. In this fuzzy system,  DNA profile data is used as an input that stores human identity along with its DNA profile. The data entered is the result of polymerase chain reaction (PCR) identification which is an electropherogram consisting of 16 loci with two alleles for each locus.  Output in this fuzzy system is the value of individual similarity with reference and with similarity levels, namely small, medium and high.

scholarly journals DMSO Improves the Ski-Slope Effect in Direct PCR

2021 ◽  
Vol 11 (4) ◽  
pp. 1943
Author(s):  
Joo-Young Kim ◽  
Ju Yeon Jung ◽  
Da-Hye Kim ◽  
Seohyun Moon ◽  
Won-Hae Lee ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Pcr Amplification ◽  
Analytical Techniques ◽  
Direct Pcr ◽  
Dna Profile ◽  
Novel Technologies ◽  
Specific Amplification ◽  
Polymerase Chain ◽  
Dna Profiles

Analytical techniques such as DNA profiling are widely used in various fields, including forensic science, and novel technologies such as direct polymerase chain reaction (PCR) amplification are continuously being developed in order to acquire DNA profiles efficiently. However, non-specific amplification may occur depending on the quality of the crime scene evidence and amplification methods employed. In particular, the ski-slope effect observed in direct PCR amplification has led to inaccurate interpretations of the DNA profile results. In this study, we aimed to reduce the ski-slope effect by using dimethyl sulfoxide (DMSO) in direct PCR. We confirmed that DMSO (3.75%, v/v) increased the amplification yield of large-sized DNA sequences more than that of small-sized ones. Using 50 Korean buccal samples, we further demonstrated that DMSO reduced the ski-slope effect in direct PCR. These results suggest that the experimental method developed in this study is suitable for direct PCR and may help to successfully obtain DNA profiles from various types of evidence at crime scenes.

Conditional Genotypic Probabilities for Microsatellite Loci

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1973-1980
Author(s):  
Jinko Graham ◽  
James Curran ◽  
B S Weir
Keyword(s):  
Short Tandem Repeats ◽  
Tandem Repeats ◽  
Dirichlet Distribution ◽  
Forensic Dna ◽  
Match Probability ◽  
Microsatellite Genotype ◽  
Allelic State ◽  
Forensic Assessments ◽  
Dna Profiles ◽  
Short Tandem

Abstract Modern forensic DNA profiles are constructed using microsatellites, short tandem repeats of 2–5 bases. In the absence of genetic data on a crime-specific subpopulation, one tool for evaluating profile evidence is the match probability. The match probability is the conditional probability that a random person would have the profile of interest given that the suspect has it and that these people are different members of the same subpopulation. One issue in evaluating the match probability is population differentiation, which can induce coancestry among subpopulation members. Forensic assessments that ignore coancestry typically overstate the strength of evidence against the suspect. Theory has been developed to account for coancestry; assumptions include a steady-state population and a mutation model in which the allelic state after a mutation event is independent of the prior state. Under these assumptions, the joint allelic probabilities within a subpopulation may be approximated by the moments of a Dirichlet distribution. We investigate the adequacy of this approximation for profiled loci that mutate according to a generalized stepwise model. Simulations suggest that the Dirichlet theory can still overstate the evidence against a suspect with a common microsatellite genotype. However, Dirichlet-based estimators were less biased than the product-rule estimator, which ignores coancestry.

scholarly journals Autotetraploid Emergence via Somatic Embryogenesis in Vitis vinifera Induces Marked Morphological Changes in Shoots, Mature Leaves, and Stomata

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1336
Author(s):  
Caterina Catalano ◽  
Loredana Abbate ◽  
Antonio Motisi ◽  
Dalila Crucitti ◽  
Vincenzo Cangelosi ◽  
...  
Keyword(s):  
Somatic Embryogenesis ◽  
Morphological Changes ◽  
Ploidy Levels ◽  
Dna Profile ◽  
Morphological Alterations ◽  
Cell Pair ◽  
Mature Leaves ◽  
Induction Process ◽  
Ploidy Changes ◽  
Dna Profiles

Polyploidy plays an important role in plant adaptation to biotic and abiotic stresses. Alterations of the ploidy in grapevine plants regenerated via somatic embryogenesis (SE) may provide a source of genetic variability useful for the improvement of agronomic characteristics of crops. In the grapevine, the SE induction process may cause ploidy changes without alterations in DNA profile. In the present research, tetraploid plants were observed for 9.3% of ‘Frappato’ grapevine somatic embryos regenerated in medium supplemented with the growth regulators β-naphthoxyacetic acid (10 µM) and N6-benzylaminopurine (4.4 µM). Autotetraploid plants regenerated via SE without detectable changes in the DNA profiles were transferred in field conditions to analyze the effect of polyploidization. Different ploidy levels induced several anatomical and morphological changes of the shoots and mature leaves. Alterations have been also observed in stomata. The length and width of stomata of tetraploid leaves were 39.9 and 18.6% higher than diploids, respectively. The chloroplast number per guard cell pair was higher (5.2%) in tetraploid leaves. On the contrary, the stomatal index was markedly decreased (12%) in tetraploid leaves. The observed morphological alterations might be useful traits for breeding of grapevine varieties in a changing environment.

scholarly journals UK epidemic strains of meticillin-resistant Staphylococcus aureus in clinical samples from Malta

2008 ◽  
Vol 57 (11) ◽  
pp. 1394-1398 ◽  
Author(s):  
Simon W. J. Gould ◽  
Jess Rollason ◽  
Anthony C. Hilton ◽  
Paul Cuschieri ◽  
Laura McAuliffe ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Great Britain ◽  
Surveillance System ◽  
Clinical Samples ◽  
Geographical Distance ◽  
Pfge Analysis ◽  
Dna Profile ◽  
The Uk ◽  
Dna Profiles ◽  
Southern European Countries

Since 1999, the European Antimicrobial Resistance Surveillance System (EARSS) has monitored the rise in infection due to a number of organisms, including meticillin-resistant Staphylococcus aureus (MRSA). The EARSS reported that MRSA infections within intensive care units account for 25–50 % of infections in many central and southern European countries, these included France, Spain, Great Britain, Malta, Greece and Italy. Each country has defined epidemic MRSA (EMRSA) strains; however, the method of spread of these strains from one country to another is unknown. In this current study, DNA profiles of 473 isolates of MRSA collected from the UK and Malta were determined by PFGE. Analysis of the data showed that two countries separated by a large geographical distance had a similar DNA profile pattern. Additionally it was demonstrated that strains of EMRSA normally found in the UK were also found in the Maltese cohort (EMRSA 15 and 16). A distinct DNA profile was found in the Maltese cohort, which may be a local EMRSA, and accounted for 14.4 % of all Maltese isolates. The appearance of the same MRSA and EMRSA profiles in two separate countries suggests that MRSA can be transferred out of their country of origin and potentially establish in a new locality or country.

On the Statistical Significance of one Pair of Monozygotic Twins in Clinical Genetics

1963 ◽  
Vol 12 (4) ◽  
pp. 317-323
Author(s):  
L. Gedda
Keyword(s):  
Twin Pair ◽  
Statistical Significance ◽  
Statistical Treatment ◽  
Monozygotic Twins ◽  
Monozygotic Twin ◽  
Clinical Genetics ◽  
Pair Comparison ◽  
Monozygotic Twin Pair ◽  
Development Result

SUMMARYA case of one twin pair concordant or discordant as to a given disease is always very important for Clinical Genetics, especially when it is monozygotic. In Clinical Genetics, isolated pairs occur to the physician, and the diagnosis must therefore be based on intra-pair comparison. The statistical treatment of the case must consider the fact that a concordant monozygotic twin pair represents a statistical universe rather than a statistical unit. This entails taking into account many traits concerning the time of onset, the symptoms, development, result of treatment, etc. Suggestions are made for the statistical treatment of such cases.

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