Thomas Bajanowski

The publication of population genetic data in the International Journal of Legal Medicine: guidelines

Since the 10 or 11 century AD, Vineta has been a major trade city at the Baltic Sea. It is generally assumed that the population consists of Wends and Slavs. Here, we analyzed eleven X chromosomal STRs in 200 women and 300 men who could prove their ancestry in Vineta for at least twenty-five generations and compared the results with German, Polish, Finnish and Swedish populations. For almost 200 years Vineta was the most important harbour at the South of the Baltic Sea, and even after the Wendish Crusade in the 12 century AD, a part of the Christianisation efforts in this geographical region, it remained a major trade city. Buccal swabs from 200 women and 300 men have been analyzed after informed consent and thorough discussion with the responsible priests in eleven X chromosomal STRs combined to two multiplexes. Samples were obtained and analyzed after advice of the Medical Ethics Committee of the University of Vineta in accordance with the declaration of Helsinki. The anonymity of the individuals investigated was preserved corresponding to the rules of data protection of the Human Medical Faculty Vineta. DNA extraction, PCR, analysis on an ABI310 genetic analyzer and statistical evaluation have been done as described before [2]. The allele frequencies and the results of the forensic efficiency parameter calculations are given in Table S1 and Table S2. Combined forensic efficiency parameters were calculated for all STRs with the exception of DXS7424, for which linkage disequilibrium to DXS101 has previously been detected [3], as follows: combined power of discrimination for males 0.99999999, combined power of discrimination for females greater than 0.999999999 and combined mean exclusion chance for trios 0.999991. The frequency of DXS101–DXS7424 haplotypes is shown in Table S3. Linkage disequilibrium between DXS101 and DXS7424 has not been tested for our samples because the number of investigated individuals was too small. Two rare alleles were found in the samples from Vineta, the allele 61 in DXS8377 and the allele 7.3 in DXS9898. Both have been verified by sequencing as described before [2]. Genetic distances were estimated for each STR marker with the exception of DXS7424—due to the linkage disequilibrium to DXS101—to different European populations [4–8] and non-European populations [9, 10] as available (see Table S4 for results). In summary, there were only few differences between the peoples from Vineta and other Northern European populations, but major differences to the populations from Brazil and the Ivory Coast, as expected.

Sudden infant death syndrome and long QT syndrome: an epidemiological and genetic study

Sudden infant death syndrome (SIDS) is a frequent cause of death among infants. The etiology of SIDS is unknown and several theories, including fatal ventricular arrhythmias, have been suggested. We performed an epidemiological and genetic investigation of SIDS victims to estimate the presence of inherited long QT syndrome (LQTS) as a contributor for SIDS. Forty-one consecutively collected and unrelated SIDS cases were characterized by clinical and epidemiological criteria. We performed a comprehensive gene mutation screening with single-strand conformation polymorphism analysis and sequencing techniques of the most relevant LQTS genes to assess mutation frequencies. In vitro characterization of identified mutants was subsequently performed by heterologous expression experiments in Chinese hamster ovary cells and in Xenopus laevis oocytes. A positive family history for LQTS was suspected by mild prolonged Q-T interval in family members in 2 of the 41 SIDS cases (5%). In neither case, a family history of sudden cardiac death was present nor a mutation could be identified after thorough investigation. In another SIDS case, a heterozygous missense mutation (H105L) was identified in the N-terminal region of the KCNQ1 (LQTS 1) gene. Despite absence of this mutation in the general population and a high conservational degree of the residue H105 during evolution, electrophysiological investigations failed to show a significant difference between wild-type and KCNQ1H105L/minK-mediated IKs currents. Our data suggest that a molecular diagnosis of SIDS related to LQTS genes is rare and that, even when an ion channel mutation is identified, this should be regarded with caution unless a pathophysiological relationship between SIDS and the electrophysiological characterization of the mutated ion channel has been demonstrated.

Influence of the examiner’s qualification and sources of error during stage determination of the medial clavicular epiphysis by means of computed tomography

Computed tomography (CT) of the medial clavicular epiphysis has been well established in forensic age estimations of living individuals undergoing criminal proceedings. The present study examines the influence of the examiner’s qualification on the determination of the clavicular ossification stage. Additionally, the most frequent sources of error made during the stage assessment process should be uncovered. To this end, thin-slice CT scans of 1,420 clavicles were evaluated by one inexperienced and two experienced examiners. The latter did the evaluations in consensus. Two classification systems, a five-stage system and a substaging system for the main stages 2 and 3, were used. Prior to three of his six assessment sessions, the inexperienced examiner was specifically taught staging of clavicles. Comparison of the examiners’ results revealed increasing inter- and intraobserver agreements with increasing state of qualification of the inexperienced examiner (from κ= 0.494 to 0.674 and from κ= 0.634 to 0.783, respectively). The attribution of a not-assessable anatomic shape variant to an ossification stage was identified as the most frequent error during stage determination (n= 349), followed by the overlooking of the epiphyseal scar defining stage 4 (n= 144). As to the clavicular substages, classifying substage 3a instead of 3b was found to be the most frequent error (n= 69). The data of this study indicate that κ values must not be considered as objective measures for inter- and intraobserver agreements. Furthermore, a high degree of specific qualification, particularly the knowledge about the diversity of anatomic shape variants, appears to be mandatory and indispensable for reliable evaluation of the medial clavicular epiphysis.

Analysis of 155 consecutive forensic exhumations with emphasis on undetected homicides

A total of 155 consecutive forensic exhumations performed in Münster, Germany from 1967 to 2001 were evaluated retrospectively on the basis of the autopsy report, the police report and the death certificate. Histology and toxicology were performed in most cases. The postmortem intervals varied from 8 days to 8 years. Compared to other countries, the autopsy rate was low (1.2–1.4%) and the exhumation rate high (0.016%): principle of reciprocity. The cause of death could be clearly determined in 103 cases (66.5%) and histology or toxicology were decisive in 40%. Some findings were discernable using immunohistochemistry after considerable postmortem intervals, such as acute myocardial infarction after 1 year and pneumonia after 2 years and a diazepam intoxication was determined after 4.5 years. Major deviations between the cause of death as stated on the death certificate and as diagnosed after autopsy existed in 57 cases (37%). A more detailed analysis revealed five subgroups. 1. primary suspicion of intoxication (n=18) confirmed in 6 cases including 3 homicides (with parathion, clozapin, diazepam) which are described in more detail. 2. primary suspicion of homicide other than poisoning (n=51) confirmed in 19 cases. There was a serial killing of 15 patients by injection of air. In the remaining 4 cases, a shaken infant, craniocerebral injuries from blows with beer bottles, a craniocerebral gunshot and a multiplicity of blunt force injuries were diagnosed. The latter two cases are described in more detail. Superficial external examinations and the low autopsy rate were 2 common reasons for the occurrence of “buried homicides” (n=22)—not a single forensic autopsy had been performed directly after the death of the victims. 3. primary suspicion of medical malpractice (n=39). 4. accidents including traffic accidents (n=30). 5. clarification of the cause of death, circumstances or identity (n=17). Exhumations were frequently successful for recovering evidence which should better have been collected immediately after the death of an individual. Exhumations can also be regarded as an instrument to evaluate the quality of death certificates and death investigations.

Good shedder or bad shedder—the influence of skin diseases on forensic DNA analysis from epithelial abrasions

The successful analysis of weak biological stains by means of highly sensitive short tandem repeat (STR) amplification has been increased significantly over the recent years. Nevertheless, the percentage of reliably analysable samples varies considerably between different crime scene investigations even if the nature of the stains appears to be the same. It has been proposed that the amount and quality of DNA left at a crime scene may be due to individual skin conditions (among other factors). Therefore, we investigated DNA from handprints from 30 patients acutely suffering from skin diseases like atopic dermatitis, psoriasis or skin ulcer before and after therapy by STR amplification using the new and highly sensitive Powerplex® ESX17 kit in comparison to 22 healthy controls. Handprints from atopic dermatitis patients showed a correct and reliable DNA profile in 90% and 40% of patients before and after therapy, respectively. Regarding psoriasis patients, we detected full DNA profiles in only 64% and 55% of handprints before and after therapy. In contrast, in ulcus patients and controls, full DNA profiles were obtained in much lower numbers. We conclude that active skin diseases like atopic dermatitis or psoriasis have a considerable impact on the amplificable DNA left by skin contact with surfaces. Since up to 7% of adults in European countries suffer from one of these diseases, this could explain at least partially the varying quality of DNA from weak stains.

Bio-medicolegal scientific research in Europe: a comprehensive bibliometric overview.

In times of globalisation, the future of bio-medicolegal sciences in Europe depends on the scientific community’s ability to develop new strategies for research, to introduce new and generally accepted standards, to develop new analytical methods, all in order to draw up inter-site, multidisciplinary and interdisciplinary long-term research projects, eligible for European Union (EU) funding. To analyse the scientific output and to identify the topics of greatest interest and appeal in these sciences, an innovative method has been developed to select and analyse publications. This method has been applied to analyse a total of 21,176 records from PubMed out of which 5,826 papers were suitable for further analysis because they were published in national and international journals in the time between January 1, 2005 and June 1, 2010 by European authors in the field of interest. In 69% of all manuscripts, authors presented results of systematic research (original articles); 84% of the papers were written in English language. The cumulative impact factor increased from 1,670 points in 2005 to 1,878 in 2009, and extrapolated 2,812 points in 2010. The most frequent topics were the description of new analytical methods in forensic toxicology (5.7% of all papers), the analysis of short tandem repeat systems (STR, 5.6%) as well as the analysis of injury mechanisms in forensic pathology and clinical forensic medicine (4.9%). If the impact factor related potential of different topics is calculated (ratio of frequency of papers and frequency of impact points achieved), SIDS research reaches 1.64 points, followed by studies on mtDNA (1.59) and the development of new analytical methods in forensic toxicology (1.49). The findings made in the present bibliometric analysis reveal a clear and interesting overall picture of the European scientific production and productivity and could be used to identify the most innovative research lines.

Bio-medicolegal guidelines and protocols: survey and future perspectives in Europe

The preservation of uniqueness and the enhancement of the value of evidence in legal medicine is based on the implementation and development of a “quality management system,” which includes a continuous education of specialists, the introduction and application of guidelines and protocols, as well as mechanisms of internal quality control. This ongoing process shows differences with regard to various fields of knowledge such as forensic genetics, toxicology, forensic pathology or forensic psychiatry, especially if different European countries are compared. To get an overview on the development of legal medicine in different European countries, a questionnaire was developed and sent to representatives of 42 European countries to verify the existence of bio-medicolegal guidelines and protocols. A National Society of Legal Medicine is established in 27 out of 32 countries (84%) which could be included in the final analyses. In 25 countries (78%), a specialisation is necessary as a prerequisite of inclusion in a national register, and 30 of the countries (94%) have guidelines in at least one field of legal medicine. The most common guidelines concern forensic pathology (in the fields of professional qualification and sudden death), forensic toxicology (driving under the influence of drugs and substance testing) and forensic genetics (paternity testing and personal identification). The findings of this study show that comparison is possible and can be a basis for further consensus in the European medicolegal community. The process of harmonisation of the medicolegal autopsy rules in Europe initiated in 1990 was a first step on this way. Further consensus is necessary and might be gained by developing European guidelines for each field within the subdisciplines, based on a standard European Guideline Format.

Cardiac arrhythmias and sudden death in infancy: implication for the medicolegal investigation

Genetically transmitted diseases are an important cause of juvenile sudden cardiac death (SCD). In a considerable proportion of individuals in which a medicolegal investigation is performed, structural heart disease is absent, and the medical examiner fails to discover an adequate cause of death. In such cases, an inherited arrhythmogenic disease should be considered, which manifests with life-threatening ventricular tachycardia or SCD. Molecular diagnosis is progressively becoming an important tool for these questions. Therefore, postmortem genetic testing (“molecular autopsy”) should be considered as a part of the comprehensive medicolegal investigation in SCD cases without apparent structural heart disease. It will have implications not only for the deceased individual but also for living family members in preventing (further) cardiac events by expert counseling, appropriate lifestyle adjustment, and adequate treatment, if available.

Head covering and the risk for SIDS: findings from the New Zealand and German SIDS case-control studies

OBJECTIVES. The aim of this investigation was to identify risk factors for being found with the head covered in sudden infant death syndrome cases and determine whether head covering was likely to be an agonal event or potentially part of the causal pathway in some cases. By using the data from 2 sudden infant death syndrome case-control studies, consistency of the findings could be assessed. METHODS. Two case-control studies were assessed: (1) the New Zealand Cot Death Study (1987–1990, 393 sudden infant death syndrome cases) and (2) a German SIDS case-control study (1998–2001, 333 sudden infant death syndrome cases). RESULTS. The proportion of sudden infant death syndrome cases in which infants were found with their head covered was 15.6% in the New Zealand study and 28.1% in the German study. Being found with head covering was associated with older infant age. In both studies, being found with head covering was associated with being very sweaty when found. Head covering was also associated with the incidence and severity of thymic petechiae in both studies. Both the position in which the child was placed to sleep and the position in which the child was found were not associated with head covering. CONCLUSIONS. The finding that sudden infant death syndrome cases in which infants were found with their heads covered were often very sweaty suggests that head covering was not an agonal event and that it preceded the death and may have been causally related to the death. Infants who were found with their head covered were older, which probably reflects motor development.

Enhanced reactivity of Alz-50 antibody in brains of sudden infant death syndrome victims versus brains with lethal hypoxic/ischemic injury. Diagnostic significance after application of the ImmunoMax technique on routine paraffin material.

Abstract Alz-50 antibody is immunoreactive with brain tissue of subjects with Alzheimer’s disease and can also be demonstrated by immunocytochemistry in neurons of vibratome-prepared brain tissue of victims of sudden infant death syndrome (SIDS). The application of a slightly modified ImmunoMax method enabled us to demonstrate Alz-50 immunoreactivity in paraffin-embedded material. The Alz-50 epitope was detected in the hippocampus region and in nuclei of the medulla oblongata at the level of the inferior olivary protuberance in three diagnostic groups: victims of SIDS (n = 10), infants dying of subacute hypoxia/ischemia with subsequent (re-)perfusion (n=9), and infants dying of acute ischemia without (re-) perfusion (n = 7). Quantitative evaluation of the hippocampal cortex and the nucleus olivaris inferior disclosed a significantly (P < 0.05) higher percentage of Alz-50-reactive neurons in SIDS cases than in the control groups (hippocampal cortex and nucleus olivaris; SIDS victims: median = 100%; subacute hypoxia/ischemia: median = 33.6– 81%; acute ischemia: median = 89.2–99%). Semiquantitative analysis revealed an equally pronounced preponderance of Alz-50-reactive neurons in SIDS victims versus the control groups. This greater expression in SIDS victims may be due to an ongoing hypoxia/ischemia during agony, but the present paucity of knowledge prohibits definitive elucidation. Nevertheless, the method described here appears to offer the realistic possibility of distinguishing SIDS cases from cases of sudden death in infants due to other causes, i.e., it offers for the first time a positive criterion for the diagnosis of SIDS.