Role of mitochondrial DNA in identification

Abstract

The molecular marker that has revolutionized the discipline of human identification is the Mitochondrial DNA (mtDNA), which has revolutionarily redefined the sunset in the fields of forensic science, anthropological studies and genealogies in the last three decades. This overall overview is looking at the versatile use of the simple use of the method in identification processes with the current understanding of the methodology frameworks, technology development and their practical applications. The unique properties of the mitochondrial DNA, such as a large number of copies per cell (100-1,000 copies when compared to two copies of the nuclear DNA), strict patterns of maternal inheritance, high resistance to environmental disintegration and the circular structure of the genome makes the use of the mitochondrial DNA to be invaluable in analyzing degraded, old, or restricted biological samples in which the more conventional nuclear DNA technology would be inadequate.

The systematic review of the literature is based on an assessment of the efficacy of the various type of analyses of the mtDNA technique in various tasks of identifying crime, including forensic casework at the crime scene with damaged evidence, cold case investigations, victim identification after a mass disaster, and anthropological studies. Historical development since early 1990s methodologies up to modern Massively Parallel Sequencing technology is factored into the analysis of the development of quality assurance standards, statistical interpretation models, and population genetic issues that are a requirement to quality evaluation of evidence.

Comparative analysis shows that although the use of the program has proven itself to be very useful in problematic sample conditions and adult line following, it has lower discriminatory capability than nuclear DNA markers and is unable to distinguish individuals that share common maternal genetic groups. The review focuses on such fundamental technical problems as contamination prevention, heteroplasmy interpretation, mixture analysis, and heterocellularity of the nuclear mitochondrial DNA segments. Statistical models on computing probability of matches, likelihood ratios and information on estimating a confidence interval is identified together with international standards of quality assurance on laboratory accreditation, staff qualification and on protocols of the validation of the analytical procedures.

The results emphasize the point that the properly used and carefully regarded quality-control doctor-level products of the mtDNA analysis can be used with superior identification features as a complement to the nuclear DNA techniques. The focus in future will be on technology integration, the overall expansion of databases, greater standardization, and multi-marker methods that incorporate both the nuclear coupled with the sexual chromosomal markers and markers of ancestry to maximize the accuracy of the identification in all the forensic, anthropological and archaeological.