In this review, we highlighted the DNA markers and their applications in forensic medicine which included the study of genetic variation or polymorphism, markers for genetic variation, types of variation, diallelic polymorphisms (SNPs and Indels), haplotypes, autosomal short tandem repeat (STRs), Y-chromosome short tandem repeat (Y-STRs) and Y chromosome. This is a useful tool for tracing human evolution, analysis of Y-chromosomal microsatellite haplotypes in globally human populations, organization of the human mitochondrial genome, and mitochondrial coding region as a source for variability and interpretation of sequence data. The light has been focused and directed in this study to establish the basic forensic genetic information, knowledge, data and statistics which might be so ultimately helpful practically in forensic science and criminology and to let evaluate and present the DNA weight evidences in medico-legal institute and courts of law.

The objectives of the study included the detection of genetic variation of 21 autosomal short tandem repeats (STRs) loci from random unrelated individuals in the middle and South Arab people of Iraq, the Forensic efficiency parameters of the autosomal 21 genetic loci using power plex21® kit and to evaluate the importance of these loci for forensic genetic purposes and the possibility to use the new kit in routine practical work. FTA® Technology was utilized to extract DNA from blood collected on FTA™ paper. Twenty one (21) STR loci including D3S1358, D13S317, D19S433 and Amelogenin were amplified by using power plex21® kit. PCR products were detected by genetic analyzer 3130xL then, the data processed and analyzed by PowerStatsV1.2 software. Several statistical parameters of genetic and forensic efficiencies based on allelic frequencies have been estimated. This includes the observed heterozygosity (Ho), expected heterozygosity (He), paternity index (PI), random match probability (RMP), power of discrimination (PD), chance of exclusion (CE), polymorphic information content (PIC) and P-value. The power of discrimination values for autosomal tested loci was from 75 to 96% therefore those loci can be safely used to establish a DNA-based database for Iraq population for identifical purpose. The high PIC values of the selected markers confirm their usefulness for genetic polymorphism studies and linkage mapping programs in human as well. The mean heterozygosity observed, expected and mean PIC values across the 20 loci were 0.79, 0.83 and 0.81, respectively indicating high gene diversity. A total of nine off-ladder alleles and one tri-allelic pattern were detected in this study.

The first objective of this study was the detection of mitochondrial hypervariable HVII and HVIII regions. Secondly, the study evaluates the importance of these positions for forensic genetic purposes and establishes the degree of variation characteristic of a fragment. Blood samples were collected from 270 healthy unrelated male living in Middle and South of Iraq. FTA® Technology was utilized to extract DNA. A portion of a noncoding region encompassing positions 37 to 340 for HVII and encompassing positions 438 to 574 for HVIII, was amplified in accordance with the Anderson reference sequence. By using EZ-10 spin column the PCR products were purified, sequenced and detected by using the ABI 3730xL Genetic Analyzer. New polymorphic positions 57, 63, 101, 469 and 482 are described that may be very important for forensic identification purpose in the future. This study shows the importance of the adoption of mitochondria in forensic medicine and criminal diagnosis and a private Iraqi society was discovered as the study sites. Further study on larger number of samples from different Iraqi ethics groups is suggested to confirm the results obtained by this study.

This study evaluates the mitochondrial noncoding regions by using the Sanger sequencing method for application in Forensic Science. FTA® Technology (FTA™ paper DNA extraction) was utilized to extract DNA. Portion of coding region encompassing positions from (10,716 to 11,184) amplified in accordance with the Anderson reference sequence. PCR products purified by EZ-10 spin column were then sequenced and detected using the ABI 3730 × L DNA Analyzer. A new polymorphic positions 10,750 and 10,790 that are described may be suitable sources in future for identification purpose. The data obtained can be used to identify variable nucleotide positions characterized by frequent occurrence, most promising for identification variants.

The aim of this research is to study the mitochondria non-coding region by using Sanger sequencing technique and establish the degree of variation characteristic of a fragment. FTA® Technology (FTA™ paper DNA extraction) is utilized to extract DNA. A portion of a non-coding region encompassing positions 438 to 574 for HVIII amplified in accordance with the Anderson reference sequence. PCR products purified by EZ-10 spin column were then sequenced and detected by using the ABI 3730xL DNA analyzer. The new polymorphic positions 469 and 482 that are described in this study may in future be suitable sources for identification purpose. The data obtained can be used to identify variable nucleotide positions characterized by frequent occurrence, most promising for identification variants.