Investigator Argus X-12 study on the population of northern Croatia

Abstract

X chromosome STR typing has emerged recently as a powerful tool, complementary to autosomal STR typing, in solving complex forensic and missing person cases. Investigator® Argus X-12 is a commercial product that allows co-amplification of 12 X chromosomal markers belonging to four linkage groups (LGs). In this study, we analyzed by capillary electrophoresis blood samples from 100 females and 102 males from a population of northern Croatia. Statistical analysis included calculation of allele and haplotype frequencies, as well as forensic parameters. The most informative marker for the northern Croatia population was DXS10135 with PIC=0.9211 and a total of 27 alleles. The least polymorphic marker was DXS8378 with 6 alleles. The proportion of observed haplotypes from the number of possible haplotypes varied from 2.74–8.57% across all LGs, with LG1 being the most informative. Of the 11 tested world populations compared to the population of northern Croatia, significant differences in genetic distance (FST) were found for Greenlandic and all non-European populations. We found that all tested markers are in HWE and can thus be used for match probability calculation. Because of high combined power of discrimination in both men and women, Investigator® Argus X-12 is applicable for the northern Croatia population in routine forensic casework.

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“…Since autosomal STR analyses revealed the number of discrepant loci between the alleged father and female child less than three and left these paternity testing cases unsolved, additional X-linked STR analyses using Investigator ® Argus X-12 kit (QIAGEN, GmbH, Hilden, Germany) were included for confirmation or exclusion of paternity. Studies proved usability and efficiency of this kit in kinship testing cases (Hering et al, 2015) and population-genetic researches (Crnjac et al, 2017). Analysis of 12 X-STR loci yielded only one mismatch between child and the alleged father, caused by a singlestep mutation at DXS10135 locus in the Case 1, and complete matching at all analysed X-STR loci in the Case 2.…”

“…Besides high heterozygosity, discriminating power, clearly defined repetitive units and precisely determined allelic variants, simple amplification and detection of STR markers make them ideal for forensic analyses (Khalil et al, 2008;Primorac et al, 2014;Gomes et al, 2020). STR markers located on the autosomal, X and Y chromosomes are highly informative, practical and reliable for all kinds of forensic-genetic analyses including parentage testing, what was strongly supported by many population-genetic studies focused on investigating allele frequencies and forensic parameters (such as heterozygosity, power of discrimination, power of exclusion, polymorphic information content, matching probability and typical paternity index) of autosomal STR (Al-Eitan and Tubaishat, 2016;Al-Eitan et al, 2019;Al-Eitan et al, 2020;Pilav et al, 2020;Takic Miladinov et al, 2020) and X-STR loci (Grskovic et al, 2013;Crnjac et al, 2017;Veselinovic et al, 2018) in different populations. Generally, parentage testing follows Mendelian inheritance law, according to which child receives one allele from the mother and the other allele from the father .…”

Expanded Croatian 12 X-STR loci database with an overview of anomalous profiles

“…In addition to the already published data for northern [2], central [3] and southern Croatia [4], allele and haplotype frequencies for eastern Croatia (100 females and 103 males) and western Croatia (48 females and 146 males) are given in Supplementary material 1 (Tables S1-S4). In both additional regions, HWE was confirmed for all loci.…”

“…As the purpose of this study is to build comprehensive forensic database based on 12 X-STR loci for the Croatian population, we expanded data set of the already published 598 profiles [2][3][4] with additional 397 profiles and consolidated Investigator® Argus X-12 Kit typing results. The ensuing comprehensive database encompasses 995 individuals, originating from five historic-cultural regions of the northern [2], central [3], southern [4], eastern and western part of the country (Figure 1). The Republic of Croatia is a European country bordering with Slovenia and Hungary in the north, Serbia and Bosnia and Herzegovina in the east, Montenegro in the south and Italy in the south-west.…”

DNA Paternıty Testıng wıth Two Mısmatches: Our Experıence

“…Besides high heterozygosity, discriminating power, clearly defined repetitive units and precisely determined allelic variants, simple amplification and detection of STR markers make them ideal for forensic analyses (Khalil et al, 2008;Primorac et al, 2014;Gomes et al, 2020). STR markers located on the autosomal, X and Y chromosomes are highly informative, practical and reliable for all kinds of forensic-genetic analyses including parentage testing, what was strongly supported by many population-genetic studies focused on investigating allele frequencies and forensic parameters (such as heterozygosity, power of discrimination, power of exclusion, polymorphic information content, matching probability and typical paternity index) of autosomal STR (Al-Eitan and Tubaishat, 2016;Al-Eitan et al, 2019;Al-Eitan et al, 2020;Pilav et al, 2020;Takic Miladinov et al, 2020) and X-STR loci (Grskovic et al, 2013;Crnjac et al, 2017;Veselinovic et al, 2018) in different populations. Generally, parentage testing follows Mendelian inheritance law, according to which child receives one allele from the mother and the other allele from the father .…”