Population Substructure Can Significantly Affect Reliability of a DNA-led Process of Identification of Mass Fatality Victims

• Published in: Journal of forensic sciences Vol. 52; no. 4; pp. 874 - 878
• Main Authors: Kračun, Stjepan Krešimir, Ćurić, Goran, Biruš, Ivan, Džijan, Snježana, Lauc, Gordan
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.07.2007; Wiley Subscription Services, Inc
• Subjects: Computer Simulation; Consanguinity; Croatia; Deoxyribonucleic acid; Disasters; DNA; DNA Fingerprinting - methods; DNA Fingerprinting - standards; DNA typing; Female; Forensic chemistry; Forensic Genetics; forensic science; Forensic sciences; Genetic testing; Genetics, Population; Haplotypes; human identification; Humans; inbreeding; Male; mini-haplotypes; Molecular biology; population substructure; STR loci; Croatia
• ISSN: 0022-1198; 1556-4029
• DOI: 10.1111/j.1556-4029.2007.00492.x

:  Aiming to evaluate the effects of population substructure on the reliability of a DNA correspondence in the process of human identification, we used the model of “in silico” constructed populations with and without substructure. Effects of population substructure were evaluated at the level of locus heterozygosity, Hardy–Weinberg equilibrium and mini‐haplotype distribution. Inbreeding in a subpopulation of 100 individuals through 10 generations did not significantly alter the level of heterozygosity and Hardy–Weinberg equilibrium. However, analysis of mini‐haplotype distribution revealed a significant homogenization in separated subpopulations. Average observed mini‐haplotype frequency (fo) increased to threefold from expected values (fe), and the number of mini‐haplotypes with fo/fe above 10 increased over sixfold, suggesting that the effects of population substructure on calculated likelihood ratios (LR) might be larger than previously estimated. In most criminal cases, this would not represent a problem, whereas for identifications in large‐scale mass fatality events, population substructure might considerably increase the risk of false identification.