PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Forensic Genetics”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed2003

A-elute alleles of the ABO blood group system in Japanese.

The ABO blood group system is important in forensic genetics, as well as transfusion medicine. Since the elucidation of the molecular basis of ABO gene regulation, nucleotides of variant alleles or suballeles have been analyzed by polymerase chain reaction (PCR)-based methods and sequencing. Ael (A-elute) is one of the subgroups of A in the ABO system. By analyzing the suballeles responsible for Ael phenotype by PCR-RFLP and PCR direct sequencing, we found seven types of Ael allele. The allele frequency of ABO*Ael in a Japanese population was calculated to be 0.0049.

ABO Blood-Group System↗
PubMed2000

mtDNA hypervariable region II (HVII) sequences in human evolution studies.

Variation in human mitochondrial DNA (mtDNA) has been used to infer the origin and migration patterns in human populations. mtDNA analysis has been focused mainly on the first hypervariable region (HVI). Nevertheless, although many studies of the second hypervariable region (HVII) have been carried out during recent years, the correlation between the first and the second hypervariable regions has not been well established. We have analysed 71 individuals from a relatively isolated region at the westernmost edge of continental Europe (Galicia, NW Iberian peninsula) and we have used available HVII sequence information from another 17 European and African populations. The results show high concordance between the two hypervariable regions, not only in variability levels but also in other phylogenetic aspects. The study of the population structure through an AMOVA analysis shows a low level of heterogeneity in the European populations. Nevertheless, we have found some inconsistency in the results, which are related to the mutation rate in these two hypervariable regions. These results are compatible with a high heterogeneity of mutation rates across the HVII region and stress the interest of HVII in population and forensic genetics.

Base Sequence↗
PubMedDate not supplied

DNA profiles of chimeric twins, TS and MR using the single-locus-probe technique.

A pair of blood-group-chimeric twins, TS and MR and their family have been investigated with the single-locus-probe DNA technique for restriction fragment length polymorphism in five variable-numbers-of-tandem-repeat systems. An admixture of DNA from the other twin could be demonstrated in both twins, leading to a possible false-genotype determination in at least one system. Chimerism is a potential pitfall in DNA investigations with single-locus probes in forensic genetics.

Blotting, Southern↗
PubMedDate not supplied

Statistical power of an exact test of Hardy-Weinberg proportions of genotypic data at a multiallelic locus.

A computer algorithm for numerical evaluation of the statistical power of an exact test of Hardy-Weinberg genotypic proportions (HWP), developed here, indicates that the power is dependent on the number of segregating alleles as well as allele frequencies. While low levels of departure from the null hypothesis are difficult to detect from single-locus data, should such deviation be due to population substructuring, multiple loci, at each of which the number of segregating alleles is large (as seen with hypervariable loci), may easily detect even low levels of departure from HWP. Undetected small levels of departure may still provide conservative estimates of genotype frequencies from allele frequency data, following the current practice in forensic genetics.

Algorithms↗
PubMed2005

Challenges of DNA profiling in mass disaster investigations.

In cases of mass disaster, there is often a need for managing, analyzing, and comparing large numbers of biological samples and DNA profiles. This requires the use of laboratory information management systems for large-scale sample logging and tracking, coupled with bioinformatic tools for DNA database searching according to different matching algorithms, and for the evaluation of the significance of each match by likelihood ratio calculations. There are many different interrelated factors and circumstances involved in each specific mass disaster scenario that may challenge the final DNA identification goal, such as: the number of victims, the mechanisms of body destruction, the extent of body fragmentation, the rate of DNA degradation, the body accessibility for sample collection, or the type of DNA reference samples availability. In this paper, we examine the different steps of the DNA identification analysis (DNA sampling, DNA analysis and technology, DNA database searching, and concordance and kinship analysis) reviewing the "lessons learned" and the scientific progress made in some mass disaster cases described in the scientific literature. We will put special emphasis on the valuable scientific feedback that genetic forensic community has received from the collaborative efforts of several public and private USA forensic laboratories in assisting with the more critical areas of the World Trade Center (WTC) mass fatality of September 11, 2001. The main challenges in identifying the victims of the recent South Asian Tsunami disaster, which has produced the steepest death count rise in history, will also be considered. We also present data from two recent mass fatality cases that involved Spanish victims: the Madrid terrorist attack of March 11, 2004, and the Yakolev-42 aircraft accident in Trabzon, Turkey, of May 26, 2003.

DNA Fingerprinting↗
PubMed1997

[Classification of isolated skeletal elements using aDNA typing].

Analysis of ancient DNA of material found in the Lichtensteinhöhle, a burial site of the Younger Bronze Age has been used for the first time to assign isolated skeletal elements to corresponding individuals. The method involved DNA typing through amplification of five Short Tandem Repeat loci which are also used in forensic genetics for the determination of kinship and identification. From all of the examined bone samples DNA was successfully extracted and amplification by means of Polymerase Chain Reaction could be carried out. For the skeletal elements allelic profiles which are specific for an individual were set up. These profiles made it possible to recognize bones belonging to one individual. Elements which were not from this individual could be excluded with certainty by aDNA analysis.

Bone and Bones↗
PubMed2003

Precision studies using the ABI prism 3100 genetic analyzer for forensic DNA analysis.

Precision studies using the ABI Prism 3100 Genetic Analyzer have been conducted by performing multiple runs of the AmpFlSTR Identifiler allelic ladder, 9947A kit positive control DNA and the 250-base-pair fragment from the internal size standard (GeneScan LIZ-500). Intra-run and inter-run precision data demonstrates the sizing reproducibility of the 3100 instrument for forensic applications. This precision data is utilized to assist in making allele assignments for outlier and variant alleles (i.e., 'off-ladder' alleles). It also provides a means of addressing systematic variations due to temperature fluctuations, polymer (POP-4) or capillary effects, and associated troubleshooting efforts.

Alleles↗
PubMed2003

A molecular genetic approach for forensic animal species identification.

This study investigated potential markers within chromosomal, mitochondrial DNA (mtDNA) and ribosomal RNA (rRNA) with the aim of developing a DNA based method to allow differentiation between animal species. Such discrimination tests may have important applications in the forensic science, agriculture, quarantine and customs fields. DNA samples from five different animal individuals within the same species for 10 species of animal (including human) were analysed. DNA extraction and quantitation followed by PCR amplification and GeneScan visualisation formed the basis of the experimental analysis. Five gene markers from three different types of genes were investigated. These included genomic markers for the beta-actin and TP53 tumor suppressor gene. Mitochondrial DNA markers, designed by Bataille et al. [Forensic Sci. Int. 99 (1999) 165], examined the Cytochrome b gene and Hypervariable Displacement Loop (D-Loop) region. Finally, a ribosomal RNA marker for the 28S rRNA gene optimised by Naito et al. [J. Forensic Sci. 37 (1992) 396] was used as a possible marker for speciation. Results showed a difference of only several base pairs between all species for the beta-actin and 28S markers, with the exception of Sus scrofa (pig) beta-actin fragment length, which produced a significantly smaller fragment. Multiplexing of Cytochrome b and D-Loop markers gave limited species information, although positive discrimination of human DNA was evident. The most specific and discriminatory results were shown using the TP53 gene since this marker produced greatest fragment size differences between animal species studied. Sample differentiation for all species was possible following TP53 amplification, suggesting that this gene could be used as a potential animal species identifier.

Actins↗
PubMed1992

Genetic structure of forensic populations.

DNA-based identification depends on the probability that two different individuals have the same phenotype, which is given by kinship theory. Together with the large and consistent body of evidence on human population structure, kinship theory provides a sound basis for forensic use of DNA markers.

DNA Fingerprinting↗
PubMedDate not supplied

[A complex forensic-medical molecular-genetic examination of the victims of terroristic bombing in Moscow underground].

The authors emphasize the need in coordination when conducting expert examinations in investigation of accidents with a great number of victims. Coordination is of special importance for combined application of molecular-genetic technologies and standard forensic medical investigations. The experience in experts cooperation in investigation of terroristic bombing in Moscow underground on February 6, 2004, according to algorithm of combined use of conventional forensic medical methods and innovating techniques of molecular-genetic identification for personal identification of dead bodies in accidents with a great number of victims is demonstrated.

Algorithms↗
PubMed1992

Sample size requirements for addressing the population genetic issues of forensic use of DNA typing.

DNA typing offers a unique opportunity to identify individuals for medical and forensic purposes. Probabilistic inference regarding the chance occurrence of a match between the DNA type of an evidentiary sample and that of an accused suspect, however, requires reliable estimation of genotype and allele frequencies in the population. Although population-based data on DNA typing at several hypervariable loci are being accumulated at various laboratories, a rigorous treatment of the sample size needed for such purposes has not been made from population genetic considerations. It is shown here that the loci that are potentially most useful for forensic identification of individuals have the intrinsic property that they involve a large number of segregating alleles, and a great majority of these alleles are rare. As a consequence, because of the large number of possible genotypes at the hypervariable loci that offer the maximum potential for individualization, the sample size needed to observe all possible genotypes in a sample is large. In fact, the size is so large that even if such a huge number of individuals could be sampled, it could not be guaranteed that such a sample was drawn from a single homogeneous population. Therefore adequate estimation of genotypic probabilities must be based on allele frequencies, and the sample size needed to represent all possible alleles is far more reasonable. Further economization of sample size is possible if one wants to have representation of only the frequent alleles in the sample, so that the rare allele frequencies can be approximated by an upper bound for forensic applications.

Alleles↗
PubMed2026

Forensic applicability of genetic profile generation from hair roots and shafts: Integration of retrotransposon polymorphisms and morphological predictors.

Genetic profiles were successfully obtained from hair samples both directly plucked from the scalp and indirectly from personal items such as combs and hairbrushes. Additionally, 100 genetic profiles were generated from buccal swabs from all donors, allowing the calculation of population allele and genotype frequencies. Complete genetic profiles were recovered from samples containing less than 0.012 ng of total nuclear DNA. Nuclear DNA yield per hair root was highly variable, whereas hair shafts yielded up to 2 ng of total nuDNA and in some cases less than 0.1 ng. Multiple correspondence analysis (MCA) revealed that hair growth phase and the presence of a root were not significantly associated with successful profile recovery; instead, greater hair thickness and direct sampling correlated with higher success rates. In certain cases, the Insertion/Null (INNUL) markers system, InnoTyper 21, outperformed the Power Plex Fusion 6 C STR kit. For forensic purposes, using the entire hair shaft provided better profiling outcomes than using the root alone. All Insertion/Null (INNUL) markers were in Hardy-Weinberg equilibrium, except for a few loci showing minor linkage disequilibrium. These results highlight the analytical potential of INNUL markers for obtaining nuclear DNA profiles from hair, even in challenging forensic contexts.

Humans↗
PubMed2006

Interpreting anonymous DNA samples from mass disasters--probabilistic forensic inference using genetic markers.

MOTIVATION: The problem of identifying victims in a mass disaster using DNA fingerprints involves a scale of computation that requires efficient and accurate algorithms. In a typical scenario there are hundreds of samples taken from remains that must be matched to the pedigrees of the alleged victim's surviving relatives. Moreover the samples are often degraded due to heat and exposure. To develop a competent method for this type of forensic inference problem, the complicated quality issues of DNA typing need to be handled appropriately, the matches between every sample and every family must be considered, and the confidence of matches need to be provided. RESULTS: We present a unified probabilistic framework that efficiently clusters samples, conservatively eliminates implausible sample-pedigree pairings, and handles both degraded samples (missing values) and experimental errors in producing and/or reading a genotype. We present a method that confidently exclude forensically unambiguous sample-family matches from the large hypothesis space of candidate matches, based on posterior probabilistic inference. Due to the high confidentiality of disaster DNA data, simulation experiments are commonly performed and used here for validation. Our framework is shown to be robust to these errors at levels typical in real applications. Furthermore, the flexibility in the probabilistic models makes it possible to extend this framework to include other biological factors such as interdependent markers, mitochondrial sequences, and blood type. AVAILABILITY: The software and data sets are available from the authors upon request.

Algorithms↗
PubMed1992

Population genetics in the forensic DNA debate.

The use of matching variable number of tandem repeat (VNTR) profiles to link suspects with crimes is potentially very powerful, but it has been quite controversial. Initial debate over laboratory procedures has largely given way to debate over the statistical and population genetic issues involved in calculating the frequency of a profile for a random member of a population. This frequency is used to weight the evidence of a match between suspect and crime scene material when the suspect denies responsibility for that material. A recent report from the National Research Council, intended to put to rest some of the issues, has instead raised further debate by advocating a procedure based on maximum frequencies of profile components over several different populations.

Alleles↗