Browsing by Author "Heathfield, Laura J"

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    A retrospective study investigating risk factors for sudden unexpected death in the young
    (2022) Oghenechovwen, Ogheneochuko Mary; Heathfield, Laura J; Mole, Calvin
    Sudden unexpected death in the young (SUDY) is the unanticipated demise of individuals aged between 1 and 40 years. In South Africa, these deaths are referred for forensic investigation. The primary aim of this study was to retrospectively investigate the frequency of known risk factors in SUDY cases admitted to Salt River Mortuary in Cape Town and explore differences between males and females. There were 1 088 SUDY cases identified with 0.9% (10/1 088) missing files. Reviewed cases were n=1 078, 62.6% (675/1 078) males, and 37.4% (403/1 078) females; 83.5% (901/1 078) adults and 16.4% (177/1 078) children, accounting for 5.6% of total admissions between 1 January 2010 and 31 December 2015. Despite the predominance of males, significantly more females (61.8%) were obese (p < 0.05). At least one primary medical condition was present in 53.7% of cases, with the leading conditions being tuberculosis (11.9 % of adult males), epilepsy (11.7% of adult males; 10.3% of female children), HIV (10.7% of adult females) and asthma (11.1% of male children). In the subset of the study population where information was available, before death, 74% of individuals were reported to have experienced prodromal symptoms; 37.6% of males and 32.4% of females did not seek medical intervention following symptoms. Information regarding a family history of sudden death was known in 237/1078 cases. In 3.2% of these cases, a family history of sudden death was reported. Significantly more males than females reported the use of tobacco, alcohol, and other illicit drugs (p < 0.05). More females were unemployed (p < 0.05). Interventions based on lifestyle modification, social support, pharmacologic needs, and awareness should be targeted at individuals with the above profiles, especially those with a family history of sudden death, as they may be high-risk groups. Findings from this study contribute new and relevant local reference data for SUDY risk profiles of males and females admitted to Salt River Mortuary.
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    Constructing a DNA profile frequency database for South Africa using the Qiagen Investigator 24plex GO! Kit
    (2018) Nel, Lorraine; Heathfield, Laura J
    DNA profiling is routinely used in the forensic setting to identify individuals during criminal and medico-legal investigations. Its principle is based on the molecular analysis of DNA to produce a string of alpha-numeric characters which can be matched to a known reference sample. The use of allele frequencies from the background population aids the statistical interpretation of a match and can be used to calculate the random match probability. In South Africa, allele frequency data for the background population is currently limited, which can hinder the discriminatory value of DNA evidence, particularly when only a partial profile is obtained. Therefore, the aim of this study was to generate DNA allele frequency data for four South African population groups using the QIAGEN Investigator® 24PLEX GO! Kit, which has six markers for which data does not yet exist for the South African population. Full forensic DNA profiles were generated from 655 unrelated individuals from four population groups in South Africa: Black African (n = 172), Coloured (n = 195), Indian/Asian (n = 88) and White (n = 200). A 98% first time success rate was observed using the direct PCR approach. Allele frequencies were significantly different between all four population groups at three markers (D8S1179, D2S1338 and D2S441) after a Bonferroni correction (ρ < 0.001) and sixteen novel alleles were observed. Two genetic anomalies were observed, namely triallelic patterns at the TPOX marker (n = 9) and a null allele at amelogenin (n = 1). While the sample size for the Indian/Asian population group was limited in this study, the data generated here nevertheless prospects to contribute towards the data currently published for South Africa. This, in turn, will allow for more DNA markers to be analysed during forensic casework in South Africa, as the data for its statistical interpretation is now available.
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    Ethical considerations in forensic genetics research on tissue samples collected post-mortem in Cape Town, South Africa
    (BioMed Central, 2017-11-29) Heathfield, Laura J; Maistry, Sairita; Martin, Lorna J; Ramesar, Raj; de Vries, Jantina
    Background: The use of tissue collected at a forensic post-mortem for forensic genetics research purposes remains of ethical concern as the process involves obtaining informed consent from grieving family members. Two forensic genetics research studies using tissue collected from a forensic post-mortem were recently initiated at our institution and were the first of their kind to be conducted in Cape Town, South Africa. Main body: This article discusses some of the ethical challenges that were encountered in these research projects. Among these challenges was the adaptation of research workflows to fit in with an exceptionally busy service delivery that is operating with limited resources. Whilst seeking guidance from the literature regarding research on deceased populations, it was noted that next of kin of decedents are not formally recognised as a vulnerable group in the existing ethical and legal frameworks in South Africa. The authors recommend that research in the forensic mortuary setting is approached using guidance for vulnerable groups, and the benefit to risk standard needs to be strongly justified. Lastly, when planning forensic genetics research, consideration must be given to the potential of uncovering incidental findings, funding to validate these findings and the feedback of results to family members; the latter of which is recommended to occur through a genetic counsellor. Conclusion: It is hoped that these experiences will contribute towards a formal framework for conducting forensic genetic research in medico-legal mortuaries in South Africa.
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    Novel CYP2E1 haplotype identified in a South African cohort
    (2014) Heathfield, Laura J; Dalvie, Shareefa; Kalideen, Kusha; Dandara, Collet
    Alcohol abuse accounts for approximately 2.5 million deaths annually and is the third highest risk factor for disease and disability. Alcohol is metabolised by polymorphic enzymes and the status of an individual with respect to alcohol metabolising enzymes may have forensic relevance in post-mortems. Baseline frequencies of gene variants involved in alcohol metabolism need to be established to aid the identification of suitable population-specific polymorphisms to genotype during molecular autopsies. The principal alcohol metabolising enzymes include alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH) and cytochrome P450 2E1 (CYP2E1). Six single nucleotide polymorphisms (SNPs) – rs1229984G>A and rs2066702C>T in ADH1B, rs671G>A in ALDH2, and rs3813867G>C, rs2031920C>T and rs6413432T>A in CYP2E1 – were genotyped in 150 individuals from four South African populations: Xhosa, Zulu, South African white and South African coloured. Allele frequencies for each SNP in the four population groups were 0–10% for rs1229984A, 2–12% for rs2066702T, 0–2% for rs671A, 1–4% for rs3813867C, 0–1% for rs2031920T and 3–15% for rs6413432A. Haplotype analysis revealed a novel combination of three SNPs in CYP2E1 whose effects on alcohol metabolism need further investigation. Establishment of baseline frequencies adds to our knowledge of genetic variation in alcohol metabolising enzymes and additional research is required to determine the functional significance of this novel CYP2E1 haplotype.
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    Post-mortem toxicological investigations in a paediatric population
    (2020) Louw, Ané; Davies, Bronwen B; Heathfield, Laura J
    In South Africa, little is known about the presence of drugs in infant cases admitted for post-mortem medico-legal examinations,as toxicological investigations are not routinely performed. It was hypothesised that drugs would be detected in sudden and unexpected death ofinfant (SUDI) cases admitted to Salt River Mortuary (SRM), as infantsform a vulnerable population. Biological samples (blood, vitreous humour, urine and hair) were collected from 30 infants who were admitted as SUDIcasesto Salt River Mortuary,Cape Town,between 28 May 2019 and 17 October 2019. Samples were screened for at least 750 common drugs using a SCIEX X500R QTOF. Demographic variables, social circumstances and clinical historywere recorded from the medico-legal case folder. Of the 30 SUDI cases, drugs were detected in 25 (83 %) cases, with acetaminophen (61 %) and caffeine (54 %) being most prevalent. Methaqualone (32 %) and methamphetamine (11 %),two commonly abused drugs in the Western Cape,werealsoidentified, with the former only present in hair. There were significantly more drugs detected in hair samples compared to the other samples (p < 0.0001). Therefore, while challenging in its interpretation, hair analyses provideda wealth of information concerningpossiblelonger-termdrug exposure in infants.This was particularly valuable inrevealingmethaqualoneexposure, which may have otherwise gone undetected, and which may indicate an environment of neglect. While the cause of death in most cases was natural (infectious causes) (63 %), next-of-kin seldom declared that their infant exhibited symptoms of illness orthat medication was administeredprior to death. Therefore, theresults of this study illustrate the valueof toxicological testing in SUDIcases at SRM, as well as the need to analyse multiple samples. This study provides empirical data to motivate for the SUDI investigation protocolatSRM toinclude routine toxicological analysis. This is anticipated toadd value to the medico-legal investigation as well as add social value to the lives of siblings who may also be at risk for neglect.
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    Retrospective analysis of abandoned live births, stillbirths and non-viable foetuses admitted to Salt River Mortuary, Cape Town
    (2018) du Toit, Chante; Heathfield, Laura J; Martin, Lorna J
    The abandonment of neonates in locations where discovery and survival is not intended is a global concern. These cases comprise non-viable foetuses and stillbirths (natural deaths), as well as abandoned live births (unnatural deaths); the latter having possible legal consequences. To describe the profile of abandoned neonates and obtain a global perspective of the post-mortem investigation in such cases, a systematic review of the literature on abandoned foetuses, concealed births and neonaticide was conducted. This revealed a paucity of research on the subject; only one published South African study and less than 30 studies from other parts of the world were obtained. While guidelines were available, a standard protocol for conducting the medico-legal investigation on abandoned neonates did not exist and the necessary extent of the investigation was debated. Furthermore, seemingly higher rates of abandoned neonates were observed in South Africa compared to elsewhere in the world, warranting investigation of these cases in a local setting. In an attempt to add to the data concerning abandoned neonates in South Africa, a case file review was carried out on abandoned live births, stillbirths and non-viable foetuses at Salt River Mortuary between 1 January 2012 and 31 December 2016 (n=249). Despite the majority of the cases being natural deaths, the cause of death frequently remained 'undetermined’ in these cases, often due to the presence of decomposition. Histological analyses were only performed in a small fraction of undetermined cases. Furthermore, the hypothesis that the prosecution rate of abandoned live births is extremely low was supported by this study, with only one case prosecuted in the 5- year period. For the remainder of the cases, the court status was given as either 'under investigation’ (47.8%) or 'case closed’ (47.8%). In the majority of the instances, the case was closed due to the unknown identity of the biological mother; however, DNA analyses were not performed in all of these cases. Overall, the data highlighted the need for the development and implementation of standard protocols, to ensure that cause of death and identification of the neonate can be established as far as possible.