Developmental validation of reduced-size STR Miniplex primer sets

This paper describes a developmental validation study of three Miniplex sets covering 12 of the 13 CODIS loci. As these new sets will be used for the analysis of degraded and low level DNA, the validation studies were performed using 100-125 pg of DNA, the lowest input level at which peak balance, peak intensity, and allele consistency were stable. To demonstrate the applicability of the Miniplex sets to forensic casework, these validation studies were completed in accordance with the Scientific Working Group on DNA Analysis Methods (SWGDAM). A range of tests were performed including studies of concordance with standard multiplex kits, sensitivity and reproducibility, and PCR amplification conditions. Additionally, studies of mixtures, nonhuman and environmentally degraded DNA, and simulated forensic samples were performed. Our results demonstrate that Miniplex STR amplification procedures are a robust and sensitive tool for the analysis of degraded DNA.     

Genetic data of 4 X-chromosomal short tandem repeats in a North of Portugal population

POPULATION: One hundred unrelated females and 100 unrelated males, autochthonous, healthy, from the North of Portugal.     

Pitbull mauling deaths in Detroit

Between the years 1987 and 2005, there were 6 deaths reported in Wayne County, Michigan, associated with pitbull dog attacks. This article discusses the age incidence, scene investigation, nature of the injuries, and discussion relative to fatal dog attacks, an unusual accidental type of death.     

The Mitigating Effects of Suspicion on Post-Identification Feedback and on Retrospective Eyewitness Memory

Three studies examined procedures for reducing the post-identification feedback effect. After viewing a video event, participants were then asked to identify a suspect from a target-absent photo lineup. After making their identification, some participants were given information suggesting that their identification was correct, while others were given no information about the accuracy of their identification. Some participants who received confirming feedback were also given reasons to entertain suspicion regarding the motives of the lineup administrator, either immediately (Experiment 1) or after a one-week retention interval (Experiment 2). Suspicious perceivers failed to demonstrate the confidence inflation effects typically associated with confirming post-identification feedback. In Experiment 3, the confidence prophylactic effect was tested both immediately and after a one-week retention interval. The effect of confidence prophylactic varied with retention interval such that it eliminated the effects of post-identification feedback immediately but not after a retention interval. However, the suspicion manipulation eliminated the post-identification feedback effects at both time intervals. Both theoretical and practical implications are discussed.     

Male batterers with and without psychopathy: an exploratory study in Spanish prisons

The aim of this study was to analyze the differential profile of male batterers in prison with and without psychopathy. The sample consisted of 162 perpetrators sentenced for a serious offence against their intimate partner. The prevalence of psychopathy or psychopathic traits, established according to the Psychopathy Checklist-Revised, was about 12%. The psychopathic batterers were younger, more impulsive, more suspicious, and less empathetic and had lower self-esteem than nonpsychopathic batterers. However, the psychopathic batterers were not engaged in intimate femicide more often than were the nonpsychopathic batterers. The severity of the crime was similar in both groups, so it may be attributed to other variables (e.g., substance abuse, intoxication at the time of the offence, violence history, jealousy, etc.). Implications of these results for further research and clinical practice are discussed.     

Haplotype frequencies of 16 Y-chromosome STR loci in the Barcelona metropolitan area population using Y-Filer kit

Haplotype frequencies for 16 Y-chromosomal short tandem repeat (STR) loci, included in the Y-Filer kit, were determined in 247 unrelated healthy individuals from the Barcelona metropolitan area (Catalonia, NE Spain). After PCR amplification and denaturing PAGE electrophoresis, DYS456, DYS389I, DYS390, DYS389II, DYS458, DYS19, DYS385a/b, DYS393, DYS391, DYS439, DYS635, DYS392, Y GATA H4.1, DYS437, DYS438 and DYS448 loci were typed. The aim of this study is to evaluate the performance in our population of the 16 loci of the Y-chromosome present in the new Y-Filer commercial identification kit, and acquire haplotype frequencies for mathematic processing of the forensic diagnosis in our geographical working area. In this sample, all haplotypes were unique. From the forensic point of view, the combined polymorphisms of the Y-Filer kit provide a high diagnostic efficiency.     

Genetic data of 10 X-STRs in a Spanish population sample

In this work, we present population genetic data of 10 X-chromosome STRs (DXS8378, DXS9898, DXS8377, HPRTB, GATA172D05, DXS7423, DXS6809, DXS7132, DXS101 and DXS6789) obtained from sample of 145 unrelated female individuals belonging to Valencia (Spain), a region located in the east of the Iberian Peninsula. All the markers studied present high genetic diversities, similar to those previously reported in other European population samples. No deviations from Hardy-Weinberg equilibrium were observed, with the exception of DXS101 locus. Allele frequencies and parameters of forensic interest for each X-STR were calculated. High mean exclusion chance and power of discrimination values were obtained by combining these 10 X-linked markers. Population comparisons (exact test of population differentiation; pairwise genetic distances) were carried out and low genetic distances were found between our sample and those from other Spanish or European regions.     

Heteroplasmy in hair: differences among hair and blood from the same individuals are still a matter of debate

The analysis of mitochondrial DNA (mtDNA) is a useful tool in forensic cases when sample contents too little or degraded nuclear DNA to genotype by autosomal short tandem repeat (STR) loci, but it is especially useful when the only forensic evidence is a hair shaft. Several authors have related differences in mtDNA from different tissues within the same individual, with high frequency of heteroplasmic variants in hair, as also in some other tissues. Is still a matter of debate how the differences influence the interpretation forensic protocols. One difference between two samples supposed to be originated from the same individual are related to an inconclusive result, but depending on the tissue and the position of the difference it should have a different interpretation, based on mutation-rate heterogeneity of mtDNA. In order to investigate it differences in the mtDNA control region from hair shafts and blood in our population, sequences from the hypervariable regions 1 and 2 (HV1 and HV2) from 100 Brazilian unrelated individuals were compared. The frequency of point heteroplasmy observed in hair was 10.5% by sequencing. Our study confirms the results related by other authors that concluded that small differences within tissues should be interpreted with caution especially when analyzing hair samples.     

Eugenics: progress or backward movement?]

Throughout this article there is a critical analysis of how genetics presents a dilemma for "human progress". So much so, that the legal world aims to create unequivocal norms and guarantees in relation with eugenics in order to avoid attempting against human dignity. The document makes the reader reflect on the ethical problems that eugenics can entail.