Overview of Forensic DNA Profiling and Database

2021 ◽  
pp. 23-29
Author(s):  
Sabreen Sabreen Aboujildah
Keyword(s):  
Genetic Markers ◽  
Tandem Repeats ◽  
Forensic Genetics ◽  
Human Leukocyte ◽  
Dna Profiling ◽  
Individual Identification ◽  
Forensic Dna ◽  
Forensic Dna Profiling ◽  
Victims Of Violence ◽  
Forensic Genetic

Deoxyribonucleic acid (DNA) profiling, has had a tremendous impact on forensic genetics. Before DNA profiling, all forensic genetic casework (e.g., Paternity testing, criminal casework, individual identification) was performed using classical serological genetic markers. Blood groups, human leukocyte antigen (HLA), and polymorphic protein and enzymes were used for solving forensic genetic casework using immunological and electrophoretic methodologies. These genetic markers were nevertheless limited when it was necessary to analyze minimal or degraded material, which is commonly involved in forensic cases. An STR is a region of human DNA containing an array of tandem repeats. Arrays range from only a 10 to about a hundred repeated units. This essay confers the basic concepts of operating of DNA in the criminal investigation. This review primarily summarizes the major tandem repeat markers used in forensic DNA profiling, that assist criminal’s conviction, exonerate the inferring individuals, and recognize victims of violence, catastrophes, and armed conflict.

scholarly journals Autosomal STR Profiling and Databanking in Malaysia: Current Status and Future Prospects

Genes ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1112
Author(s):  
Hashom Mohd Hakim ◽  
Hussein Omar Khan ◽  
Japareng Lalung ◽  
Bryan Raveen Nelson ◽  
Geoffrey Keith Chambers ◽  
...  
Keyword(s):  
Tandem Repeats ◽  
Dna Analysis ◽  
Dna Profiling ◽  
Individual Identification ◽  
Current Status ◽  
Weight Of Evidence ◽  
Forensic Dna ◽  
Kinship Analysis ◽  
Forensic Dna Analysis ◽  
Dna Profiles

Science and technology are extensively used in criminal investigation. From the mid- to late-1980s, one of the scientific discoveries that has had a particularly remarkable impact on this field has been the use of highly variable DNA sequence regions (minisatellites) in the human genome for individual identification. The technique was initially referred to as DNA fingerprinting, but is now more widely referred to as DNA profiling. Since then, many new developments have occurred within this area of science. These include the introduction of new genetic markers (microsatellites also known as short tandem repeats/STRs), the use of the polymerase chain reaction for target amplification, the development of DNA databases (databanking), and the advancement and/or improvement of genotyping protocols and technologies. In 2019, we described the progress of DNA profiling and DNA databanking in Malaysia for the first time. This report included information on DNA analysis regulations and legislation, STR genotyping protocols, database management, and accreditation status. Here, we provide an update on the performance of our DNA databank (numbers of DNA profiles and hits) plus the technical issues associated with correctly assigning the weight of evidence for DNA profiles in an ethnically diverse population, and the potential application of rapid DNA testing in the country. A total of 116,534 DNA profiles were obtained and stored in the Forensic DNA Databank of Malaysia (FDDM) by 2019, having increased from 70,570 in 2017. The number of hits increased by more than three-fold in just two years, where 17 and 69 hits between the DNA profiles stored in the FDDM and those from crime scenes, suspects, detainees, drug users, convicts, missing persons, or volunteers were recorded in 2017 and 2019, respectively. Forensic DNA analysis and databanking are thus progressing well in Malaysia and have already contributed to many criminal investigations. However, several other issues are discussed here, including the need for STR population data for uncharacterized population groups, and pilot trials for adopting rapid DNA profiling technology. These aspects should be considered by policy makers and law enforcement agencies in order to increase the reliability and efficiency of DNA profiling in criminal cases and in kinship analysis in Malaysia.

scholarly journals Forensic Genetics and Genotyping

2019 ◽  
Vol 20 (2) ◽  
pp. 75-86
Author(s):  
Katarina Vitoševic ◽  
Danijela Todorovic ◽  
Zivana Slovic ◽  
Radica Zivkovic-Zaric ◽  
Milos Todorovic
Keyword(s):  
Genetic Markers ◽  
Short Tandem Repeats ◽  
Tandem Repeats ◽  
Forensic Genetics ◽  
Personal Identification ◽  
Hair Color ◽  
Forensic Dna ◽  
Kinship Analysis ◽  
Dna Profile ◽  
Short Tandem

Abstract Forensic genetics represents a combination of molecular and population genetics. Personal identification and kinship analysis (e.g. paternity testing) are the two main subjects of forensic DNA analysis. Biological specimens from which DNA is isolated are blood, semen, saliva, tissues, bones, teeth, hairs. Genotyping has become a basis in the characterization of forensic biological evidence. It is performed using a variety of genetic markers, which are divided into two large groups: bi-allelic (single-nucleotide polymorphisms, SNP) and multi-allelic polymorphisms (variable number of tandem repeats, VNTR and short tandem repeats, STR). This review describes the purpose of genetic markers in forensic investigation and their limitations. The STR loci are currently the most informative genetic markers for identity testing, but in cases without a suspect SNP can predict offender’s ancestry and phenotype traits such as skin, eyes and hair color. Nowadays, many countries worldwide have established forensic DNA databases based on autosomal short tandem repeats and other markers. In order for DNA profile database to be useful at a national or international level, it is essential to standardize genetic markers used in laboratories.

scholarly journals Comparison of the Allelic Alterations between InDel and STR Markers in Tumoral Tissues Used for Forensic Purposes

Medicina ◽  
2021 ◽  
Vol 57 (3) ◽  
pp. 226
Author(s):  
Pamela Tozzo ◽  
Arianna Delicati ◽  
Anna Chiara Frigo ◽  
Luciana Caenazzo
Keyword(s):  
Colorectal Cancer ◽  
Genomic Instability ◽  
Tandem Repeats ◽  
Forensic Genetics ◽  
Tumor Type ◽  
Forensic Dna ◽  
Dna Identification ◽  
Human Dna ◽  
Tumor Transformation ◽  
Paternity Tests

Background and objectives: Over the last two decades, human DNA identification and kinship tests have been conducted mainly through the analysis of short tandem repeats (STRs). However, other types of markers, such as insertion/deletion polymorphisms (InDels), may be required when DNA is highly degraded. In forensic genetics, tumor samples may sometimes be used in some cases of human DNA identification and in paternity tests. Nevertheless, tumor genomic instability related to forensic DNA markers should be considered in forensic analyses since it can compromise genotype attribution. Therefore, it is useful to know what impact tumor transformation may have on the forensic interpretation of the results obtained from the analysis of these polymorphisms. Materials and Methods: The aim of this study was to investigate the genomic instability of InDels and STRs through the analysis of 55 markers in healthy tissue and tumor samples (hepatic, gastric, breast, and colorectal cancer) in 66 patients. The evaluation of genomic instability was performed comparing InDel and STR genotypes of tumor samples with those of their healthy counterparts. Results: With regard to STRs, colorectal cancer was found to be the tumor type affected by the highest number of mutations, whereas in the case of InDels the amount of genetic mutations turned out to be independent of the tumor type. However, the phenomena of genomic instability, such as loss of heterozygosity (LOH) and microsatellite instability (MSI), seem to affect InDels more than STRs hampering genotype attribution. Conclusion: We suggest that the use of STRs rather than InDels could be more suitable in forensic genotyping analyses given that InDels seem to be more affected than STRs by mutation events capable of compromising genotype attribution.

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