209 results on '"Kotze MJ"'
Search Results
2. Familial hypercholesterolaemia workshop for leveraging point-of-care testing and personalised medicine in association with the Lipid and Atherosclerosis Society of Southern Africa
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Marais, AD, primary, Kotze, MJ, additional, Raal, FJ, additional, Khine, AA, additional, Talmud, PJ, additional, and Humphries, SE, additional
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- 2019
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3. Mutation analysis in a small cohort of New Zealand patients originating from the United Kingdom demonstrates genetic heterogeneity in familial hypercholesterolemia
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Thiart, R, Varret, M, Lintott, CJ, Scott, RS, Loubser, O, du Plessis, L, de Villiers, JNP, Boileau, C, and Kotze, MJ
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- 2000
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4. Intronic mutations at splice junctions in the low-density lipoprotein receptor gene
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Peeters, AV, Thiart, R, de Villiers, JNP, Jensen, HK, Van Gaal, LF, and Kotze, MJ
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- 1999
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5. Evaluation of two different-gauge dental needles for the presence of blood following the application of local anesthesia by dental students
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Kotze, MJ and Labuschagne, W
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Blood-borne virus transmissions from patient to dental health care personnel are occupational hazards following needle stick injury. AIMS AND OBJECTIVES: Three local anesthetic (LA) techniques frequently used in the extraction of teeth were evaluated and compared for the presence of blood in the cartridge, needle lumen and needle surface when either 27G or 30G needles were used. DESIGN AND METHODS: The histogram function of Photoshop computer software identified differences in grey-scale value of the different blood parameters on photographs of urine dipsticks moistened with the first drop of liquid from the needle after the injection had been given and luminol spray was used to expose small quantities of blood on the surface of the needle. Blood visible to the naked eye in the LA cartridge was noted. RESULTS: A statistically significant association was found between needle diameter and visible blood in the cartridge (P=0.006), and the presence of blood in the needle lumen (P=0.029), especially with the 27G needle. CONCLUSION: There was a statistically significant difference in the presence of blood in the lumen (36%) and in the cartridge (29%) between 27G and 30G needles following the administration of LA to a patient.
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- 2015
6. Chronic disease risk management: Combining genetic testing with medical and nutrition therapy
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Kotze, MJ and Badenhorst, CH
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Overwhelming evidence indicates that diet is a key environmental factor affecting the incidence of many chronic diseases treated by medical practitioners on a daily basis. Information available in public gene databases, combined with advanced molecular technologies and nutrition research, provides the opportunity for the development of a new set of treatment and prevention strategies based partly on nutritional genomics. Nutrigenetics has been used for decades to prevent rare monogenic disorders such as phenylketonuria. Gene-diet interaction can now also be targeted to prevent or reduce the risk of many chronic conditions long before clinical manifestation. This multidisciplinary approach unites conventional medicine with genetics and lifestyle intervention for optimal health management.SA Fam Pract 2005;47(4): 40-42
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- 2013
7. Olfactory responses of Dasineura Dielsi Rübsaamen (Diptera: Cecidomyiidae) females to host plant volatiles
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Kotze, MJ and Hoffman, John
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Zoology - Abstract
Includes abstract., Includes bibliographical references., In 2001, Dasineura dielsi (Diptera: Cecidomyiidae), a gall midge, was introduced into South Africa as a biological control agent on the invasive alien plant species, Acacia cyclops (Mimosaceae). An investigation was launched to test the following hypotheses: 1) the midges respond to the scent of A. cyclops to locate suitable oviposition sites; 2) the floral scent of A. melanoxylon, A. longifolia and A. saligna resembles that of A. cyclops and this explains the insects’use of these plants too; and 3) the floral scents of African acacias are distinctly different from A. cyclops and therefore has no attraction for D. dielsi.
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- 2012
8. Somatic mutations of the APC, KRAS, and TP53 genes in nonpolypoid colorectal adenomas
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van Wyk, R, Slezak, P, Hayes, VM, Buys, CHCM, Kotze, MJ, de Jong, G, Rubio, C, Dolk, A, Jaramillo, E, Koizumi, K, and Grobbelaar, JJ
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NEOPLASTIC PROGRESSION ,RAS MUTATIONS ,endocrine system diseases ,FLAT ADENOMA ,ULCERATIVE-COLITIS ,P53 MUTATIONS ,POLYPOSIS-COLI GENE ,TUMORS ,CANCER ,digestive system diseases ,ADENOCARCINOMAS ,POLYMORPHISM - Abstract
Calorectal adenomas are macroscopically visible morphological changes of the mucosa that can develop focal carcinoma in the absence of surgical intervention. The successive molecular changes proposed to occur at different: stages in the adenoma-carcinoma sequence were primarily based on DNA studies of exophytic; polypoid-type adenomas. Nor all colorectal lesions, however, display an exophytic phenotype and a presumed distinct colorectal neoplasm, the nonpolypoid adenoma, was subsequently described as a precursor of colorectal cancer. The low incidence of KRAS mutations in nonpolypoid colorectal adenomas reported previously suggested a different genetic basis for the transformation process in these lesions. We have pursued the identification of genetic changes in benign sporadic nanpolypoid colorectal adenomas in a selected Swedish patient group with no family history of colarectal cancer. Mutation screening of the adenomarous polyposis coli (APC), KRAS, and TP53 genes was conducted using the protein truncation test, hereroduplex-single-strand conformation polymorphism analysis, and denaturing gradient: gel electrophoresis on PCR-amplified fragments. Fourteen mutations in the APC gene were characterized in 10/20 samples. Mutations in the KRAS and TP53 genes were identified in 3/57 and 4/51 adenomas, respectively. The mutation frequencies and distribution of mutations in APC correlate with published data on exophytic adenomas. The low mutation frequency of the TP53 gene is consistent with the benign nature of the research material. KRAS activation (an early event in polypoid colorectal adenomas) apparently does not play a significant role in nonpolypoid adenoma development bur may result in the development of a polypoid configuration. Genes Chromosomes Cancer 27:202-208, 2000. (C) 2000 Wiley-Liss, Inc.
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- 2000
9. A Third Major Locus for Autosomal Dominant Hypercholesterolemia maps at 1p34.1-p32
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Varret, M, Rabes, Jp, SAINT JORE, B, Cenarro, A, Marinoni, J. C., Civeira, F, Devillers, M, Krempf, M, Coulon, M, Thiart, R, Kotze, Mj, Schmidt, H, Buzzi, J. C., Kostner, Gm, Bertolini, Stefano, Pocovi, M, Rosa, A, Farnier, M, Martinez, M, Junien, C, and Boileau, C.
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- 1999
10. The significance of genetic risk factors in non-alcoholic fatty liver disease (NAFLD)
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Kruger, FC, primary and Kotze, MJ, additional
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- 2011
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11. Obesity and the metabolic syndrome: Impact of gene-diet interaction
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Kotze, MJ, primary, Marais, M, additional, and Van Rensburg, C, additional
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- 2010
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12. Cardiovascular genetic assessment and treatment in middle age to reduce the risk of heart disease and dementia in old age
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Kotze, MJ, primary, Thiart, R, additional, Hugo, FJ, additional, and Potocnik, FCW, additional
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- 2006
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13. Identification of clinically-informative biomarkers for risk stratification within the spectrum of gastro-esophageal reflux disease in the South African population
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Van Rensburg, C, primary, De Villiers, JNP, additional, Daniels, C, additional, Wright, C, additional, Kidd, M, additional, De Jong, G, additional, and Kotze, MJ, additional
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- 2006
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14. Health implications and counselling for paternity testing
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Kotze, MJ, primary, Scholtz, CL, additional, and Opperman, P, additional
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- 2006
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15. The role of molecular genetic testing in modern breast heath management
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Kotze, MJ, primary, Malan, J, additional, Pienaar, R, additional, and Apffelstaedt, J, additional
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- 2005
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16. Rapid thrombophilia genetic test facilitates improved prenatal care for mother and child
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Kotze, MJ, primary, La Grange, C, additional, and Mansvelt, EPG, additional
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- 2005
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17. Chronic disease risk management: Combining genetic testing with medical and nutrition therapy
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Kotze, MJ, primary and Badenhorst, CH, additional
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- 2005
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18. Preventing organ damage by genetic testing for hereditary haemochromatosis
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Kotze, MJ, primary, De Villiers, JNP, additional, and Van der Merwe, SW, additional
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- 2005
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19. Molecular diagnosis of hereditary hemochromatosis: application of a newly-developed reverse-hybridization assay in the South African population
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Kotze, MJ, primary, De Villiers, JNP, additional, Bouwens, CSH, additional, Warnich, L, additional, Zaahl, MG, additional, Van Der Merwe, S, additional, and Oberkanins, C, additional
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- 2004
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20. Fine mapping of region 1p32-p34.1 that contains the third major locus for autosomal dominant hypercholesterolemia
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Boileau, C., Villeger, L., Rabes, Jp, Devillers, M., Krempf, M., Cenarro, A., Farnier, M., Kotze, Mj, Kostner, Gm, Martinez, M., Junien, C., and Mathilde VARRET
21. Genomic mapping of a fourth gene involved in familial hypercholesterolemia
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Villeger, L., Mathilde VARRET, Rabes, Jp, Saint-Jore, B., Cenarro, A., Deviliers, M., Krempf, M., Kotze, Mj, Kostner, Gm, Martinez, M., Junien, C., and Boileau, C.
22. Incorporating familial risk, lifestyle factors, and pharmacogenomic insights into personalized noncommunicable disease (NCD) reports for healthcare funder beneficiaries participating in the Open Genome Project.
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De Klerk M, Van Der Merwe N, Erasmus J, Whati L, Moremi KE, Olivier DW, and Kotze MJ
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Introduction: An ethics-guided decision-making framework was developed for applying pathology-supported genetic testing, a multifaceted pharmacodiagnostic approach that translates population risk stratification into clinical utility. We introduce this service, supported by the Open Genome Project, which aligns with the beneficence principle in personalized medicine., Methods: Genetic testing of six noncommunicable disease pathways was conducted as part of a pilot program, benchmarked against a readiness checklist for implementation of genomic medicine in Africa. Patient referral criteria were determined using healthcare funder claims data, employing the Adjusted Clinical Groupers and Resource Utilization Band risk rating structure to identify potential nonresponders to treatment., Results: Three of the 135 doctors (2.2%) invited expressed immediate disinterest in the pilot, while 24 (17.8%) actively participated. Inherited, lifestyle-triggered, and therapy-related pathologies were simultaneously assessed in case reports, with special medical scheme reimbursement tariff codes applied to 25 patient referrals. The findings were used by the participating genetic counselor to select three patients for whole exome sequencing, utilizing a novel, level-up data processing algorithm for adaptive reporting., Conclusion: This study demonstrated the implementation of genomics into an evolving workflow for patients with a history of frequent clinic visits. Eliminating the cost barrier provided valuable insights to guide future reimbursement policy decisions., (© 2024 The Author(s). Annals of Human Genetics published by University College London (UCL) and John Wiley & Sons Ltd.)
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- 2024
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23. Clinical relevance of double heterozygosity revealed by next-generation sequencing of homologous recombination repair pathway genes in South African breast cancer patients.
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van der Merwe NC, Buccimazza I, Rossouw B, Araujo M, Ntaita KS, Schoeman M, Vorster K, Napo K, Kotze MJ, and Oosthuizen J
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- Humans, Female, South Africa, Middle Aged, Adult, Germ-Line Mutation, Aged, Clinical Relevance, Breast Neoplasms genetics, Breast Neoplasms pathology, High-Throughput Nucleotide Sequencing methods, Recombinational DNA Repair genetics, BRCA1 Protein genetics, Genetic Predisposition to Disease, BRCA2 Protein genetics, Heterozygote
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Purpose: Genetically predisposed breast cancer (BC) patients represent a minor but clinically meaningful subgroup of the disease, with 25% of all cases associated with actionable variants in BRCA1/2. Diagnostic implementation of next-generation sequencing (NGS) resulted in the rare identification of BC patients with double heterozygosity for deleterious variants in genes partaking in homologous recombination repair of DNA. As clinical heterogeneity poses challenges for genetic counseling, this study focused on the occurrence and clinical relevance of double heterozygous BC in South Africa., Methods: DNA samples were diagnostically screened using the NGS-based Oncomine™ BRCA Expanded Research Assay. Data was generated on the Ion GeneStudio S5 system and analyzed using the Torrent Suite™ and reporter software. The clinical significance of the variants detected was determined using international variant classification guidelines and treatment implications., Results: Six of 1600 BC patients (0.375%) tested were identified as being bi-allelic for two germline likely pathogenic or pathogenic variants. Most of the variants were present in BRCA1/2, including two founder-related small deletions in three cases, with family-specific variants detected in ATM, BARD1, FANCD2, NBN, and TP53. The scientific interpretation and clinical relevance were based on the clinical and tumor characteristics of each case., Conclusion: This study increased current knowledge of the risk implications associated with the co-occurrence of more than one pathogenic variant in the BC susceptibility genes, confirmed to be a rare condition in South Africa. Further molecular pathology-based studies are warranted to determine whether clinical decision-making is affected by the detection of a second pathogenic variant in BRCA1/2 and TP53 carriers., (© 2024. The Author(s).)
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- 2024
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24. Navigating the genetic landscape of breast cancer in South Africa amidst a developing healthcare system.
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Oosthuizen J, Van der Merwe NC, and Kotze MJ
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Breast cancer is a significant global health issue as it represents the leading cause of death in women worldwide. In 2021, the World Health Organization established the Global Breast Cancer Initiative framework with the aim to reduce the breast cancer mortality rate by the year 2040. In countries with developing healthcare systems, such as South Africa, the implementation of first-world technologies has been slow. We provide an overview of the strides taken to improve the cost-effectiveness of genetic service delivery for breast cancer patients in South Africa - from advances in the technology utilized for BRCA founder genotyping to variant screening in moderate-to high-penetrance genes. We furthermore reflect on research undertaken to improve accessibility by means of population-directed point-of-care genetic testing that is ideal for use in a primary healthcare setting. We also report on a pilot study utilizing exome sequencing at the intersection between research and service delivery. Finally, we discuss and conclude on the controversies, research gaps, and future prospects based on the most recent developments in first-world countries that are implementable in developing countries to improve early detection of breast cancer and overall disease management., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Oosthuizen, Van der Merwe and Kotze.)
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- 2024
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25. Incorporating functional genomics into the pathology-supported genetic testing framework implemented in South Africa: A future view of precision medicine for breast carcinomas.
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Christowitz C, Olivier DW, Schneider JW, Kotze MJ, and Engelbrecht AM
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- Humans, South Africa, Female, High-Throughput Nucleotide Sequencing methods, Breast Neoplasms genetics, Breast Neoplasms pathology, Precision Medicine methods, Genomics methods, Genetic Testing methods
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A pathology-supported genetic testing (PSGT) framework was established in South Africa to improve access to precision medicine for patients with breast carcinomas. Nevertheless, the frequent identification of variants of uncertain significance (VUSs) with the use of genome-scale next-generation sequencing has created a bottleneck in the return of results to patients. This review highlights the importance of incorporating functional genomics into the PSGT framework as a proposed initiative. Here, we explore various model systems and experimental methods available for conducting functional studies in South Africa to enhance both variant classification and clinical interpretation. We emphasize the distinct advantages of using in vitro, in vivo, and translational ex vivo models to improve the effectiveness of precision oncology. Moreover, we highlight the relevance of methodologies such as protein modelling and structural bioinformatics, multi-omics, metabolic activity assays, flow cytometry, cell migration and invasion assays, tube-formation assays, multiplex assays of variant effect, and database mining and machine learning models. The selection of the appropriate experimental approach largely depends on the molecular mechanism of the gene under investigation and the predicted functional effect of the VUS. However, before making final decisions regarding the pathogenicity of VUSs, it is essential to assess the functional evidence and clinical outcomes under current variant interpretation guidelines. The inclusion of a functional genomics infrastructure within the PSGT framework will significantly advance the reclassification of VUSs and enhance the precision medicine pipeline for patients with breast carcinomas in South Africa., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: MJK is a non-executive director and shareholder of Gknowmix Pty Ltd., to facilitate genetic research translation into clinical practice. DWO is a consultant for Gknowmix Pty Ltd. The other authors have no conflict interest to declare., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2024
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26. Detecting the most critical clinical variables of COVID-19 breakthrough infection in vaccinated persons using machine learning.
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Daramola O, Kavu TD, Kotze MJ, Kamati O, Emjedi Z, Kabaso B, Moser T, Stroetmann K, Fwemba I, Daramola F, Nyirenda M, van Rensburg SJ, Nyasulu PS, and Marnewick JL
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Background: COVID-19 vaccines offer different levels of immune protection but do not provide 100% protection. Vaccinated persons with pre-existing comorbidities may be at an increased risk of SARS-CoV-2 breakthrough infection or reinfection. The aim of this study is to identify the critical variables associated with a higher probability of SARS-CoV-2 breakthrough infection using machine learning., Methods: A dataset comprising symptoms and feedback from 257 persons, of whom 203 were vaccinated and 54 unvaccinated, was used for the investigation. Three machine learning algorithms - Deep Multilayer Perceptron (Deep MLP), XGBoost, and Logistic Regression - were trained with the original (imbalanced) dataset and the balanced dataset created by using the Random Oversampling Technique (ROT), and the Synthetic Minority Oversampling Technique (SMOTE). We compared the performance of the classification algorithms when the features highly correlated with breakthrough infection were used and when all features in the dataset were used., Result: The results show that when highly correlated features were considered as predictors, with Random Oversampling to address data imbalance, the XGBoost classifier has the best performance (F1 = 0.96; accuracy = 0.96; AUC = 0.98; G-Mean = 0.98; MCC = 0.88). The Deep MLP had the second best performance (F1 = 0.94; accuracy = 0.94; AUC = 0.92; G-Mean = 0.70; MCC = 0.42), while Logistic Regression had less accurate performance (F1 = 0.89; accuracy = 0.88; AUC = 0.89; G-Mean = 0.89; MCC = 0.68). We also used Shapley Additive Explanations (SHAP) to investigate the interpretability of the models. We found that body temperature, total cholesterol, glucose level, blood pressure, waist circumference, body weight, body mass index (BMI), haemoglobin level, and physical activity per week are the most critical variables indicating a higher risk of breakthrough infection., Conclusion: These results, evident from our unique data source derived from apparently healthy volunteers with cardiovascular risk factors, follow the expected pattern of positive or negative correlations previously reported in the literature. This information strengthens the body of knowledge currently applied in public health guidelines and may also be used by medical practitioners in the future to reduce the risk of SARS-CoV-2 breakthrough infection., Competing Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2023.)
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- 2023
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27. Disability in multiple sclerosis is associated with vascular factors: An ultrasound study.
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Kemp MC, Johannes C, van Rensburg SJ, Kidd M, Isaacs F, Kotze MJ, and Engel-Hills P
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- Humans, Carotid Intima-Media Thickness, Multiple Sclerosis diagnostic imaging
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Background: Although multiple sclerosis (MS) is an immune-related disorder, pharmaceutical interventions targeting the immune system do not stop or reverse disability progression; the major challenge for this condition. Studies show that disability progression in MS is associated with vascular comorbidity and brain volume loss, indicating that a multi-targeted approach is required to prevent debilitation. The aim of the present study was to examine the associations between vascular ultrasound, disability, biochemistry and lifestyle data in people with MS (pwMS)., Methods: Extracranial vascular ultrasound was performed on 51 pwMS and 25 age-matched controls. Sonographic interrogation determined carotid intima-media thickness (cIMT) and abnormal blood flow patterns. Disability was assessed using the Expanded Disability Status Scale (EDSS). Biochemical and lifestyle data were obtained for all participants., Results: The EDSS had a highly significant positive association with the cIMT of the right (r = 0.63; p = 0.001) and left (r = 0.49; p = 0.001) common carotid arteries and negative associations with the peak systolic blood flow velocity of the right vertebral artery (r = -0.42; p = 0.01) as well as end-diastolic velocity of the left internal carotid artery (r = -0.47; p = 0.01). These associations were significantly influenced by biochemical and lifestyle factors. Both cIMT and age showed significant associations with the EDSS. When cIMT was adjusted for age in a regression analysis, the association between the EDSS and the cIMT remained significant (p < 0.01), while the age association was reduced to being significant only at 10% (p = 0.06). There was no association between the use of MS medication and the EDSS (p = 0.56)., Conclusion: PwMS who had increased cIMT, a surrogate marker for atherosclerosis, and reduced carotid artery blood flow velocities were at risk for greater disability over and above the effect of aging. These findings provide important information for disease management and disability prevention in pwMS. Modification of diet and lifestyle may promote the unhindered flow of essential nutritional factors into the brain in pwMS., (Copyright © 2022. Published by Elsevier Inc.)
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- 2023
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28. An investigation of the correlation of vitamin D status and management outcomes in patients with severe COVID-19 at a South African tertiary hospital.
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Jalavu TP, Sigwadhi LN, Kotze MJ, Yalew A, Ngah V, Tamuzi JL, Chapanduka ZC, Allwood BW, Koegelenberg CF, Irusen EM, Lalla U, Matsha TE, Erasmus RT, Zumla A, Zemlin AE, and Nyasulu PS
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Background: Severe COVID-19 has a poor prognosis, and biomarkers may predict disease severity. This study aimed to assess the effect of baseline Vitamin D (VitD) inadequacy on outcome of patients with severe COVID-19 admitted to intensive care unit (ICU) in a tertiary hospital in South Africa., Methods: Patients with confirmed SARS-CoV-2 were recruited during wave II of the pandemic in Cape Town. Eighty-six patients were included in the study. They were categorized into three groups "VitD deficient, VitD insufficient and VitD sufficient". We combined the VitD deficient with insufficient group to form "VitD inadequate'' group. Cox regression analysis was done to assess the association between VitD status and mortality. Factors with p< 0.05 in adjusted multivariable cox regression were considered statistically significant., Results: The proportion of VitD inadequacy was 64% (55/86), with significantly higher proportion of hypertension (66%; p 0.012). Kaplan Meir curve showed no significant difference in the probability of survival among the COVID-19 patients admitted in the ICU with or without VitD inadequacy. However, patients with elevated serum creatinine were significantly more at risk of dying (Adjusted Hazard Ratio 1.008 (1.002 - 1.030, p<0.017)., Conclusion: Our study found a high prevalence of VitD inadequacy (combined deficiency and insufficiency) in COVID-19 patients admitted to the ICU. This may indicate a possible risk of severe disease. Whilst there was no statistically significant relationship between VitD status and mortality in this cohort, baseline VitD may be an important prognostic biomarker in COVID-19 patients admitted to the ICU, particularly in those with comorbidities that predispose to VitD deficiency., Competing Interests: No conflict of interest declared, (© 2023 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.)
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- 2023
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29. Data sharing: A Long COVID perspective, challenges, and road map for the future.
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Oladejo SO, Watson LR, Watson BW, Rajaratnam K, Kotze MJ, Kell DB, and Pretorius E
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'Long COVID' is the term used to describe the phenomenon in which patients who have survived a COVID-19 infection continue to experience prolonged SARS-CoV-2 symptoms. Millions of people across the globe are affected by Long COVID. Solving the Long COVID conundrum will require drawing upon the lessons of the COVID-19 pandemic, during which thousands of experts across diverse disciplines such as epidemiology, genomics, medicine, data science, and computer science collaborated, sharing data and pooling resources to attack the problem from multiple angles. Thus far, there has been no global consensus on the definition, diagnosis, and most effective treatment of Long COVID. In this work, we examine the possible applications of data sharing and data science in general with a view to, ultimately, understand Long COVID in greater detail and hasten relief for the millions of people experiencing it. We examine the literature and investigate the current state, challenges, and opportunities of data sharing in Long COVID research., Competing Interests: Competing interests We have no competing interests to declare.
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- 2023
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30. Pathology-supported genetic testing for the application of breast cancer pharmacodiagnostics: family counselling, lifestyle adjustments and change of medication.
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Okunola AO, Baatjes KJ, Zemlin AE, Torrorey-Sawe R, Conradie M, Kidd M, Erasmus RT, van der Merwe NC, and Kotze MJ
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- Humans, Female, Genetic Testing, Vitamin D therapeutic use, Life Style, Breast Neoplasms diagnosis, Breast Neoplasms drug therapy, Breast Neoplasms genetics, Osteoporosis etiology, Osteoporosis genetics
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Background: Pathology-supported genetic testing (PSGT) enables transitioning of risk stratification from the study population to the individual., Research Design and Methods: We provide an overview of the translational research performed in postmenopausal breast cancer patients at increased risk of osteoporosis due to aromatase inhibitor therapy, as the indication for referral. Both tumor histopathology and blood biochemistry levels were assessed to identify actionable disease pathways using whole exome sequencing (WES)., Results: The causes and consequences of inadequate vitamin D levels as a modifiable risk factor for bone loss were highlighted in 116 patients with hormone receptor-positive breast cancer. Comparison of lifestyle factors and WES data between cases with vitamin D levels at extreme upper and lower ranges identified obesity as a major discriminating factor, with the lowest levels recorded during winter. Functional polymorphisms in the vitamin D receptor gene contributed independently to therapy-related osteoporosis risk. In a patient with invasive lobular carcinoma, genetic counseling facilitated investigation of the potential modifying effect of a rare CDH1 variant co-occurring with BRCA1 c.66dup (p.Glu23ArgfsTer18)., Conclusion: Validation of PSGT as a three-pronged pharmacodiagnostics tool for generation of adaptive reports and data reinterpretation during follow-up represents a new paradigm in personalized medicine, exposing significant limitations to overcome.
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- 2023
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31. Pathology-supported genetic testing presents opportunities for improved disability outcomes in multiple sclerosis.
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Johannes C, Moremi KE, Kemp MC, Whati L, Engel-Hills P, Kidd M, van Toorn R, Jaftha M, van Rensburg SJ, and Kotze MJ
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- Humans, Life Style, Genetic Testing, Multiple Sclerosis genetics
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Background: Lipid metabolism may impact disability in people with multiple sclerosis (pwMS). Methods: Fifty-one pwMS entered an ultrasound and MRI study, of whom 19 had followed a pathology-supported genetic testing program for more than 10 years (pwMS-ON). Genetic variation, blood biochemistry, vascular blood flow velocities, diet and exercise were investigated. Results: pwMS-ON had significantly lower (p < 0.01) disability (Expanded Disability Status Scale) than pwMS not on the program (1.91 ± 0.75 vs 3.87 ± 2.32). A genetic variant in the lipid transporter FABP2 gene (rs1799883; 2445G>A, A54T) was significantly associated (p < 0.01) with disability in pwMS not on the program, but not in pwMS-ON (p = 0.88). Vascular blood flow velocities were lower in the presence of the A-allele. Conclusion: Pathology-supported genetic testing may provide guidance for lifestyle interventions with a significant impact on improved disability in pwMS.
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- 2023
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32. Editorial: Implementation of genomic medicine in Africa: One continent, one vision.
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Kotze MJ, Mashamba-Thompson TP, and Stephens D
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Competing Interests: MK is a non-executive director and shareholder of Gknowmix (Pty) Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
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- 2023
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33. Implementation of multigene panel testing for breast and ovarian cancer in South Africa: A step towards excellence in oncology for the public sector.
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van der Merwe NC, Ntaita KS, Stofberg H, Combrink HM, Oosthuizen J, and Kotze MJ
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Translation of genomic knowledge into public health benefits requires the implementation of evidence-based recommendations in clinical practice. In this study, we moved beyond BRCA1/2 susceptibility testing in breast and ovarian cancer patients to explore the application of pharmacogenetics across multiple genes participating in homologous recombination DNA damage repair. This involved the utilisation of next-generation sequencing (NGS) at the intersection of research and service delivery for development of a comprehensive genetic testing platform in South Africa. Lack of international consensus regarding risk categorization of established cancer susceptibility genes and the level of evidence required for prediction of drug response supported the development of a central database to facilitate clinical interpretation. Here we demonstrate the value of this approach using NGS to 1) determine the variant spectrum applicable to targeted therapy and implementation of prevention strategies using the 15-gene Oncomine™ BRCA Expanded Panel, and 2) searched for novel and known pathogenic variants in uninformative cases using whole exome sequencing (WES). Targeted NGS performed as a routine clinical service in 414 South African breast and/or ovarian cancer patients resulted in the detection of 48 actionable variants among 319 (15%) cases. BRCA1/2 -associated cancers were identified in 70.8% of patients (34/48, including two double-heterozygotes), with the majority (35.3%, 12/34) representing known South African founder variants. Detection of actionable variants in established non- BRCA1/2 risk genes contributed 29% to the total percentage (14/48), distributed amongst ATM , CHEK2 , BARD1 , BRIP1 , PALB2 and TP53 . Experimental WES using a virtually constructed multi-cancer NGS panel in 16 genetically unresolved cases (and four controls) revealed novel protein truncating variants in the basal cell carcinoma gene PTCH1 (c.4187delG) and the signal transmission and transduction gene KIT (c.930delA) involved in crucial cellular processes. Based on these findings, the most cost-effective approach would be to perform BRCA1/2 founder variant testing at referral, followed by targeted multigene panel testing if clinically indicated and addition of WES in unresolved cases. This inventive step provides a constant flow of new knowledge into the diagnostic platform via a uniquely South African pathology-supported genetic approach implemented for the first time in this context to integrate research with service delivery., Competing Interests: Prof Maritha Kotze is a non-executive director and shareholder of Gknowmix Pty Ltd., to facilitate genetic research translation into clinical practice. The other authors have no conflict of interest to declare., (Copyright © 2022 van der Merwe, Ntaita, Stofberg, Combrink, Oosthuizen and Kotze.)
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- 2022
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34. Relative Hypercoagulopathy of the SARS-CoV-2 Beta and Delta Variants when Compared to the Less Severe Omicron Variants Is Related to TEG Parameters, the Extent of Fibrin Amyloid Microclots, and the Severity of Clinical Illness.
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Grobbelaar LM, Kruger A, Venter C, Burger EM, Laubscher GJ, Maponga TG, Kotze MJ, Kwaan HC, Miller JB, Fulkerson D, Huff W, Chang E, Wiarda G, Bunch CM, Walsh MM, Raza S, Zamlut M, Moore HB, Moore EE, Neal MD, Kell DB, and Pretorius E
- Subjects
- Humans, Fibrin, SARS-CoV-2, COVID-19
- Abstract
Earlier variants of SARS-CoV-2 have been associated with hypercoagulability and an extensive formation of fibrin amyloid microclots, which are considered to contribute to the pathology of the coronavirus 2019 disease (COVID-19). The newer omicron variants appear to be far more transmissible, but less virulent, even when taking immunity acquired from previous infections or vaccination into account. We here show that while the clotting parameters associated with omicron variants are significantly raised over those of healthy, matched controls, they are raised to levels significantly lower than those seen with more severe variants such as beta and delta. We also observed that individuals infected with omicron variants manifested less extensive microclot formation in platelet-poor plasma compared with those harboring the more virulent variants. The measurement of clotting effects between the different variants acts as a kind of "internal control" that demonstrates the relationship between the extent of coagulopathies and the virulence of the variant of interest. This adds to the evidence that microclots may play an important role in reflecting the severity of symptoms observed in COVID-19., Competing Interests: M.J.K. is a nonexecutive director and shareholder of Gknowmix (Pty) Ltd. E.P. is the managing director of BioCODE Technologies. E.E.M., H.B.M., M.D.N. have received research grants from Haemonetics Corporation outside the submitted work. M.D.N. has received an honorarium from Haemonetics Corporation for speaking engagements, as well as research support from Janssen Pharmaceuticals (Beerse, Belgium) and Noveome Biotherapeutics (Pittsburgh, PA) outside the submitted work. He has served as a consultant to Janssen and CSL Behring (King of Prussia, PA) and serves on the Scientific Advisory Board of Haima Therapeutics (Cleveland, OH). M.M.W. has received honoraria from Alexion Pharmaceuticals (Boston, MA)., (Thieme. All rights reserved.)
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- 2022
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35. Prevalence of symptoms, comorbidities, fibrin amyloid microclots and platelet pathology in individuals with Long COVID/Post-Acute Sequelae of COVID-19 (PASC).
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Pretorius E, Venter C, Laubscher GJ, Kotze MJ, Oladejo SO, Watson LR, Rajaratnam K, Watson BW, and Kell DB
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- Amyloid, Female, Fibrin, Humans, Male, Prevalence, SARS-CoV-2, Post-Acute COVID-19 Syndrome, COVID-19 complications, COVID-19 epidemiology, Diabetes Mellitus, Type 2
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Background: Fibrin(ogen) amyloid microclots and platelet hyperactivation previously reported as a novel finding in South African patients with the coronavirus 2019 disease (COVID-19) and Long COVID/Post-Acute Sequelae of COVID-19 (PASC), might form a suitable set of foci for the clinical treatment of the symptoms of Long COVID/PASC. A Long COVID/PASC Registry was subsequently established as an online platform where patients can report Long COVID/PASC symptoms and previous comorbidities., Methods: In this study, we report on the comorbidities and persistent symptoms, using data obtained from 845 South African Long COVID/PASC patients. By using a previously published scoring system for fibrin amyloid microclots and platelet pathology, we also analysed blood samples from 80 patients, and report the presence of significant fibrin amyloid microclots and platelet pathology in all cases., Results: Hypertension, high cholesterol levels (dyslipidaemia), cardiovascular disease and type 2 diabetes mellitus (T2DM) were found to be the most important comorbidities. The gender balance (70% female) and the most commonly reported Long COVID/PASC symptoms (fatigue, brain fog, loss of concentration and forgetfulness, shortness of breath, as well as joint and muscle pains) were comparable to those reported elsewhere. These findings confirmed that our sample was not atypical. Microclot and platelet pathologies were associated with Long COVID/PASC symptoms that persisted after the recovery from acute COVID-19., Conclusions: Fibrin amyloid microclots that block capillaries and inhibit the transport of O
2 to tissues, accompanied by platelet hyperactivation, provide a ready explanation for the symptoms of Long COVID/PASC. Removal and reversal of these underlying endotheliopathies provide an important treatment option that urgently warrants controlled clinical studies to determine efficacy in patients with a diversity of comorbidities impacting on SARS-CoV-2 infection and COVID-19 severity. We suggest that our platelet and clotting grading system provides a simple and cost-effective diagnostic method for early detection of Long COVID/PASC as a major determinant of effective treatment, including those focusing on reducing clot burden and platelet hyperactivation., (© 2022. The Author(s).)- Published
- 2022
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36. Immuno-Thrombotic Complications of COVID-19: Implications for Timing of Surgery and Anticoagulation.
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Bunch CM, Moore EE, Moore HB, Neal MD, Thomas AV, Zackariya N, Zhao J, Zackariya S, Brenner TJ, Berquist M, Buckner H, Wiarda G, Fulkerson D, Huff W, Kwaan HC, Lankowicz G, Laubscher GJ, Lourens PJ, Pretorius E, Kotze MJ, Moolla MS, Sithole S, Maponga TG, Kell DB, Fox MD, Gillespie L, Khan RZ, Mamczak CN, March R, Macias R, Bull BS, and Walsh MM
- Abstract
Early in the coronavirus disease 2019 (COVID-19) pandemic, global governing bodies prioritized transmissibility-based precautions and hospital capacity as the foundation for delay of elective procedures. As elective surgical volumes increased, convalescent COVID-19 patients faced increased postoperative morbidity and mortality and clinicians had limited evidence for stratifying individual risk in this population. Clear evidence now demonstrates that those recovering from COVID-19 have increased postoperative morbidity and mortality. These data-in conjunction with the recent American Society of Anesthesiologists guidelines-offer the evidence necessary to expand the early pandemic guidelines and guide the surgeon's preoperative risk assessment. Here, we argue elective surgeries should still be delayed on a personalized basis to maximize postoperative outcomes. We outline a framework for stratifying the individual COVID-19 patient's fitness for surgery based on the symptoms and severity of acute or convalescent COVID-19 illness, coagulopathy assessment, and acuity of the surgical procedure. Although the most common manifestation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is COVID-19 pneumonitis, every system in the body is potentially afflicted by an endotheliitis. This endothelial derangement most often manifests as a hypercoagulable state on admission with associated occult and symptomatic venous and arterial thromboembolisms. The delicate balance between hyper and hypocoagulable states is defined by the local immune-thrombotic crosstalk that results commonly in a hemostatic derangement known as fibrinolytic shutdown. In tandem, the hemostatic derangements that occur during acute COVID-19 infection affect not only the timing of surgical procedures, but also the incidence of postoperative hemostatic complications related to COVID-19-associated coagulopathy (CAC). Traditional methods of thromboprophylaxis and treatment of thromboses after surgery require a tailored approach guided by an understanding of the pathophysiologic underpinnings of the COVID-19 patient. Likewise, a prolonged period of risk for developing hemostatic complications following hospitalization due to COVID-19 has resulted in guidelines from differing societies that recommend varying periods of delay following SARS-CoV-2 infection. In conclusion, we propose the perioperative, personalized assessment of COVID-19 patients' CAC using viscoelastic hemostatic assays and fluorescent microclot analysis., Competing Interests: EEM: Research support from Haemonetics, Instrumentation Laboratory, Hemosonics, Stago, and Diapharma. HBM: Research support from Haemonetics and Instumentation Laboratory. MJK is a non-executive director and shareholder of Gknowmix (Pty) Ltd. EP is the managing director of BioCODE Technologies. MMW is on the speaker’s bureau for AstraZeneca., (Copyright © 2022 Bunch, Moore, Moore, Neal, Thomas, Zackariya, Zhao, Zackariya, Brenner, Berquist, Buckner, Wiarda, Fulkerson, Huff, Kwaan, Lankowicz, Laubscher, Lourens, Pretorius, Kotze, Moolla, Sithole, Maponga, Kell, Fox, Gillespie, Khan, Mamczak, March, Macias, Bull and Walsh.)
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- 2022
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37. A View on Genomic Medicine Activities in Africa: Implications for Policy.
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Jongeneel CV, Kotze MJ, Bhaw-Luximon A, Fadlelmola FM, Fakim YJ, Hamdi Y, Kassim SK, Kumuthini J, Nembaware V, Radouani F, Tiffin N, and Mulder N
- Abstract
Genomics policy development involves assessing a wide range of issues extending from specimen collection and data sharing to whether and how to utilize advanced technologies in clinical practice and public health initiatives. A survey was conducted among African scientists and stakeholders with an interest in genomic medicine, seeking to evaluate: 1) Their knowledge and understanding of the field. 2) The institutional environment and infrastructure available to them. 3) The state and awareness of the field in their country. 4) Their perception of potential barriers to implementation of precision medicine. We discuss how the information gathered in the survey could instruct the policies of African institutions seeking to implement precision, and more specifically, genomic medicine approaches in their health care systems in the following areas: 1) Prioritization of infrastructures. 2) Need for translational research. 3) Information dissemination to potential users. 4) Training programs for specialized personnel. 5) Engaging political stakeholders and the public. A checklist with key requirements to assess readiness for implementation of genomic medicine programs is provided to guide the process from scientific discovery to clinical application., Competing Interests: MK is a non-executive director and shareholder of Gknowmix (Pty) Ltd., that developed a database resource for research translation under the auspices of the South African Research Council. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Jongeneel, Kotze, Bhaw-Luximon, Fadlelmola, Fakim, Hamdi, Kassim, Kumuthini, Nembaware, Radouani, Tiffin and Mulder.)
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- 2022
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38. The cost impact of unselective vs selective MammaPrint testing in early-stage breast cancer in Southern Africa.
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Myburgh EJ, de Jager JJ, Murray E, Grant KA, Kotze MJ, and de Klerk H
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- Africa, Southern, Chemotherapy, Adjuvant, Cost-Benefit Analysis, Female, Humans, South Africa, Breast Neoplasms drug therapy
- Abstract
Background: MammaPrint (MP) has been applied in South Africa (SA) for decision-making in early-stage hormone receptor-positive breast cancer since 2006. The cost-impact of MP in SA has not been assessed., Aim: To assess different MP testing strategies for cost-minimization in early-stage breast carcinoma using a funder perspective., Methods: Clinico-pathologic information was extracted from a prospectively collected database. Clinical risk stratification was done using Adjuvant Online! (AOL) and the Predict V2.1 algorithm (www.predict.nhs.uk). An unselected MP testing strategy was compared to a selective strategy, testing only clinically high risk (cHigh) patients. Excluding human epidermal growth factor receptor-2 positive tumours, the costs for chemotherapy treatment and MP using funding data were used to evaluate the financial impact of these strategies., Results: In 583 patients with 601 tumours, 52% were clinically low risk (cLow) (AOL) while the average Predict 10-year survival with chemotherapy was 2.9%. MP correlated strongly with Predict and 318 (60%) patients were MP low risk. Unselective testing allowed omission of chemotherapy in 44 (8.4%) patients but escalated cost by 57.7%. Using a selective testing strategy, only 251 would be tested, de-escalating treatment in 138 (55%) and reducing cost by 19.5%. Considering a Predict value up to 3.2% as cHigh, cost would be up to 7.3% (p = 0.0467) lower with a selective testing strategy., Conclusion: MP allowed reduction in the use of adjuvant chemotherapy. Unselective use of MP increases overall costs. A selective testing strategy through clinical risk stratification using AOL/Predict results in substantial cost saving., Competing Interests: Declaration of competing interest JJ de Jager is employed in the chemical active pharmaceutical ingredient (API) manufacturing industry. However, he has no influences associated with pharmaceutical (chemotherapeutic) agents related to the treatment of breast cancer. Prof MJ Kotze is a non-executive director and shareholder of Gknowmix (Pty) Ltd., that has developed a database tool for research translation under the auspices of the South African Medical Research Council. The other authors have no affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)
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- 2021
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39. Pioneering BRCA1/2 Point-Of-Care Testing for Integration of Germline and Tumor Genetics in Breast Cancer Risk Management: A Vision for the Future of Translational Pharmacogenomics.
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Mampunye L, van der Merwe NC, Grant KA, Peeters AV, Torrorey-Sawe R, French DJ, Moremi KE, Kidd M, van Eeden PC, Pienaar FM, and Kotze MJ
- Abstract
Research performed in South African (SA) breast, ovarian and prostate cancer patients resulted in the development of a rapid BRCA point-of-care (POC) assay designed as a time- and cost-effective alternative to laboratory-based technologies currently used for first-tier germline DNA testing. In this study the performance of the new assay was evaluated for use on a portable screening device (ParaDNA), with the long-term goal to enable rollout at POC as an inventive step to meet the World Health Organization's sustainable development goals for Africa. DNA samples for germline testing were obtained retrospectively from 50 patients with early-stage hormone receptor-positive breast cancer referred for genomic tumor profiling (MammaPrint). Currently, SA patients with the luminal-type breast cancer are not routinely selected for BRCA1/2 testing as is the case for triple-negative disease. An initial evaluation involved the use of multiple control samples representing each of the pathogenic founder/recurrent variants included in the BRCA 1.0 POC Research Assay. Comparison with a validated laboratory-based first-tier real-time polymerase chain reaction (PCR) assay demonstrated 100% concordance. Clinical utility was evident in five patients with the founder BRCA2 c.7934delG variant, identified at the 10% (5/50) threshold considered cost-effective for BRCA1/2 testing. BRCA2 c.7934delG carrier status was associated with a significantly younger age (p=0.03) at diagnosis of breast cancer compared to non-carriers. In three of the BRCA2 c.7934delG carriers a high-risk MammaPrint 70-gene profile was noted, indicating a significantly increased risk for both secondary cancers and breast cancer recurrence. Initiating germline DNA testing at the POC for clinical interpretation early in the treatment planning process, will increase access to the most common pathogenic BRCA1/2 variants identified in SA and reduce loss to follow-up for timely gene-targeted risk reduction intervention. The ease of using cheek swabs/saliva in future for result generation within approximately one hour assay time, coupled with low cost and a high BRCA1/2 founder variant detection rate, will improve access to genomic medicine in Africa. Application of translational pharmacogenomics across ethnic groups, irrespective of age, family history, tumor subtype or recurrence risk profile, is imperative to sustainably implement preventative healthcare and improve clinical outcome in resource-constrained clinical settings., Competing Interests: Author DF was employed by company LGC Limited. MJK is a non-executive director and shareholder of Gknowmix (Pty) Ltd. that is involved with the development of the POC 1.0 BRCA Research Assay. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Mampunye, van der Merwe, Grant, Peeters, Torrorey-Sawe, French, Moremi, Kidd, van Eeden, Pienaar and Kotze.)
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- 2021
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40. Pathology-supported genetic testing as a method for disability prevention in multiple sclerosis (MS). Part I. Targeting a metabolic model rather than autoimmunity.
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van Rensburg SJ, van Toorn R, Erasmus RT, Hattingh C, Johannes C, Moremi KE, Kemp MC, Engel-Hills P, and Kotze MJ
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- Brain pathology, Disability Evaluation, Humans, Myelin Sheath pathology, Autoimmunity genetics, Genetic Testing, Multiple Sclerosis genetics, Multiple Sclerosis pathology, Multiple Sclerosis prevention & control
- Abstract
In this Review (Part I), we investigate the scientific evidence that multiple sclerosis (MS) is caused by the death of oligodendrocytes, the cells that synthesize myelin, due to a lack of biochemical and nutritional factors involved in mitochondrial energy production in these cells. In MS, damage to the myelin sheaths surrounding nerve axons causes disruption of signal transmission from the brain to peripheral organs, which may lead to disability. However, the extent of disability is not deterred by the use of MS medication, which is based on the autoimmune hypothesis of MS. Rather, disability is associated with the loss of brain volume, which is related to the loss of grey and white matter. A pathology-supported genetic testing (PSGT) method, developed for personalized assessment and treatment to prevent brain volume loss and disability progression in MS is discussed. This involves identification of MS-related pathogenic pathways underpinned by genetic variation and lifestyle risk factors that may converge into biochemical abnormalities associated with adverse expanded disability status scale (EDSS) outcomes and magnetic resonance imaging (MRI) findings during patient follow-up. A Metabolic Model is presented which hypothesizes that disability may be prevented or reversed when oligodendrocytes are protected by nutritional reserve. Evidence for the validity of the Metabolic Model may be evaluated in consecutive test cases following the PSGT method. In Part II of this Review, two cases are presented that describe the PSGT procedures and the clinical outcomes of these individuals diagnosed with MS., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2021
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41. Correction to: Pathology-supported genetic testing as a method for disability prevention in multiple sclerosis (MS). Part II. Insights from two MS cases.
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van Rensburg SJ, Hattingh C, Johannes C, Moremi KE, Peeters AV, van Heerden CJ, Erasmus RT, Zemlin AE, Kemp MC, Jaftha M, Khine AA, Potocnik FCV, Whati L, Engel-Hills P, van Toorn R, and Kotze MJ
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- 2021
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42. Pathology-supported genetic testing as a method for disability prevention in multiple sclerosis (MS). Part II. Insights from two MS cases.
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van Rensburg SJ, Hattingh C, Johannes C, Moremi KE, Peeters AV, van Heerden CJ, Erasmus RT, Zemlin AE, Kemp MC, Jaftha M, Khine AA, Potocnik FCV, Whati L, Engel-Hills P, van Toorn R, and Kotze MJ
- Subjects
- Humans, Iron metabolism, Life Style, Multiple Sclerosis diagnosis, Myelin Sheath metabolism, Myelin Sheath pathology, Genetic Testing methods, Iron Deficiencies metabolism, Multiple Sclerosis genetics, Multiple Sclerosis pathology
- Abstract
In Part I of this Review we evaluated the scientific evidence for a Metabolic Model of multiple sclerosis (MS). Part II outlines the implementation of an adaptive pathology-supported genetic testing (PSGT) algorithm aimed at preventing/reversing disability in two illustrative MS cases, starting with a questionnaire-based risk assessment, including family history and lifestyle factors. Measurement of iron, vitamin B12, vitamin D, cholesterol and homocysteine levels identified biochemical deficits in both cases. Case 1, after following the PSGT program for 15 years, had an expanded disability status scale (EDSS) of 2.0 (no neurological sequelae) together with preserved brain volume on magnetic resonance imaging (MRI). A novel form of iron deficiency was identified in Case 1, as biochemical testing at each hospital submission due to MS symptoms showed low serum iron, ferritin and transferrin saturation, while hematological status and erythrocyte sedimentation rate measurement of systemic inflammation remained normal. Case 2 was unable to walk unaided until her EDSS improved from 6.5 to 4.0 over 12 months after implementation of the PSGT program, with amelioration of her suboptimal biochemical markers and changes to her diet and lifestyle, allowing her to regain independence. Genotype-phenotype correlation using a pathway panel of functional single nucleotide variants (SNVs) to facilitate clinical interpretation of whole exome sequencing (WES), elucidated the underlying metabolic pathways related to the biochemical deficits. A cure for MS will remain an elusive goal if separated from nutritional support required for production and maintenance of myelin, which can only be achieved by a lifelong investment in wellness., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2021
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43. Globally Rare BRCA2 Variants With Founder Haplotypes in the South African Population: Implications for Point-of-Care Testing Based on a Single-Institution BRCA1/2 Next-Generation Sequencing Study.
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Oosthuizen J, Kotze MJ, Van Der Merwe N, Myburgh EJ, Bester P, and van der Merwe NC
- Abstract
Breast cancer patients historically benefitted from population-based genetic research performed in South Africa, which led to the development of founder-based BRCA1/2 diagnostic tests. With the advent of next-generation sequencing (NGS) technologies, the clinical utility of limited, targeted genetic assays were questioned. The study focused on mining NGS data obtained from an extensive single-institution NGS series (n=763). The aims were to determine (i) the prevalence of the most common recurrent/founder variants in patients referred for NGS directly; and (ii) to explore the data for inferred haplotypes associated with previous and potential new recurrent/founder variants. The identification of additional founder variants was essential for promoting and potentially advancing to rapid founder-based BRCA1/2 point-of-care (POC) technology as a time- and cost-effective alternative. NGS revealed actionable BRCA1/2 variants in 11.1% of patients tested ( BRCA1 - 4.7%; BRCA2 - 6.4%), of which 22.4% represented variants currently screened for using first-tier targeted genetic testing. A retrospective investigation into the overall mutation-positive rate for an extended cohort (n=1906), which included first-tier test results, revealed that targeted genetic testing identified 74% of all pathogenic variants. This percentage justified the use of targeted genetic testing as a first-tier assay. Inferred haplotype analysis confirmed the founder status of BRCA2 c.5771_5774del (rs80359535) and c.7934del (rs80359688) and revealed an additional African founder variant ( BRCA2 c.582G>A - rs80358810). A risk-benefit analysis using a questionnaire-based survey was performed in parallel to determine genetic professionals' views regarding POC testing. This was done to bridge the clinical implementation gap between haplotype analysis and POC testing as a first-tier screen during risk stratification of breast and ovarian cancer patients. The results reflected high acceptance (94%) of BRCA1/2 POC testing when accompanied by genetic counselling. Establishing the founder status for several recurrent BRCA2 variants across ethnic groups supports unselected use of the BRCA POC assay in all SA breast/ovarian cancer patients by recent local and international public health recommendations. Incorporating POC genotyping into the planned NGS screening algorithm of the Department of Health will ensure optimal use of the country's recourses to adhere to the set standards for optimal care and management for all breast cancer patients., Competing Interests: MK is a non-executive director and shareholder of Gknowmix (Pty) Ltd. that is involved with the development of the POC 1.0 BRCA Research Assay. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Oosthuizen, Kotze, Van Der Merwe, Myburgh, Bester and van der Merwe.)
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- 2021
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44. Human whole genome sequencing in South Africa.
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Glanzmann B, Jooste T, Ghoor S, Gordon R, Mia R, Mao J, Li H, Charls P, Douman C, Kotze MJ, Peeters AV, Loots G, Esser M, Tiemessen CT, Wilkinson RJ, Louw J, Gray G, Warren RM, Möller M, and Kinnear C
- Subjects
- Humans, DNA analysis, DNA genetics, Genome, Human, Genomics methods, High-Throughput Nucleotide Sequencing methods, Sequence Analysis, DNA methods, Whole Genome Sequencing methods
- Abstract
The advent and evolution of next generation sequencing has considerably impacted genomic research. Until recently, South African researchers were unable to access affordable platforms capable of human whole genome sequencing locally and DNA samples had to be exported. Here we report the whole genome sequences of the first six human DNA samples sequenced and analysed at the South African Medical Research Council's Genomics Centre. We demonstrate that the data obtained is of high quality, with an average sequencing depth of 36.41, and that the output is comparable to data generated internationally on a similar platform. The Genomics Centre creates an environment where African researchers are able to access world class facilities, increasing local capacity to sequence whole genomes as well as store and analyse the data.
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- 2021
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45. The tumor genetics of acral melanoma: What should a dermatologist know?
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Tod BM, Schneider JW, Bowcock AM, Visser WI, and Kotze MJ
- Abstract
Dermatologists stand at the gateway of individualization of classification, treatment, and outcomes of acral melanoma patients. The acral melanoma genetic landscape differs in vital ways from that of other cutaneous melanomas. These differences have important implications in understanding pathogenesis, treatment, and prognosis. The selection of molecularly targeted therapy must be adapted for acral melanoma. It is also critical to recognize that tumor development is far more complex than an isolated event, reliably treated by a medication acting on a single target. Tumors exhibit intratumor genetic heterogeneity, metastasis may have different genetic or epigenetic features than primary tumors, and tumor resistance may develop because of the activation of alternative genetic pathways. Microenvironmental, immune, and epigenetic events contribute and sustain tumors in complex ways. Treatment strategies with multiple targets are required to effectively disrupt the tumor ecosystem. This review attempts to translate the current molecular understanding of acral melanoma into digestible concepts relevant to the practice of dermatology. The focus is tumor genetics defining potentially treatable cancer pathways, contextualized within the relevant pathologic and molecular features., Competing Interests: Conflicts of interest: None disclosed.
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- 2020
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46. Pioneering Informed Consent for Return of Research Results to Breast Cancer Patients Facing Barriers to Implementation of Genomic Medicine: The Kenyan BRCA1/2 Testing Experience Using Whole Exome Sequencing.
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Torrorey-Sawe R, van der Merwe N, Mining SK, and Kotze MJ
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Introduction: Obtaining informed consent from study participants and disseminating the findings responsibly is a key principle required for ethically conducted clinical and genetic research. Reports from African researchers providing feedback on insights gained during the return of whole exome sequencing (WES) results to breast cancer patients treated in resource-limited settings is lacking., Aim: The empirical process used to fill this gap in relation to BRCA1/2 variant detection using WES provided unique insights incorporated into a pathology-supported genetic testing algorithm for return of research results to Kenyan breast cancer patients., Methods: The Informed consent form approved by the Moi Teaching and Referral Hospital in Kenya was adopted from a translational research study conducted in South Africa. Initially, the informed consent process was piloted in 16 Kenyan female patients referred for breast surgery, following a community-based awareness campaign. A total of 95 female and two male breast cancer patients were enrolled in the study from 2013 to 2016. Immunohistochemistry (IHC) results of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2) status were obtained from hospital records. DNA of patients with a family history of cancer was extracted from saliva and screened for pathogenic variants in the BRCA1/2 genes as the first step using WES., Results: Ten patients approached for participation in this study declined to sign the informed consent form. Data on IHC used as a proxy for molecular subtype were available in 8 of 13 breast cancer patients (62%) with a family history of cancer. Five BRCA 1/2 variants of uncertain clinical significance were detected, as well as a pathogenic BRCA2 variant (c.5159C > A; S1720
∗ ) in a female patient eligible for return of WES results., Conclusion: Experience gained during the qualitative pilot phase was essential to overcome challenges associated with the translation of sophisticated genetic terms into native African languages. Detection of a pathogenic BRCA 2 variant in a patient with familial breast cancer, frequently associated with hormone receptor-positive breast carcinoma as reported in this case, led to a high level of confidence on which to base risk management in future. Implementation of new technologies alongside standard pathology provides a practical approach to the application of genomic medicine in Africa., (Copyright © 2020 Torrorey-Sawe, van der Merwe, Mining and Kotze.)- Published
- 2020
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47. The relationship between measurement of in vivo brain glutamate and markers of iron metabolism: A proton magnetic resonance spectroscopy study in healthy adults.
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Burger A, Kotze MJ, Stein DJ, Janse van Rensburg S, and Howells FM
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- Adult, Biomarkers, Brain diagnostic imaging, Female, Humans, Iron, Magnetic Resonance Imaging, Male, Proton Magnetic Resonance Spectroscopy, Glutamic Acid, Glutamine
- Abstract
Fundamental human studies which address associations between glutamate and iron metabolism are needed. Basic research reports associations between glutamate and iron metabolism. Human studies report sex differences in iron metabolism and glutamate concentrations, which suggest that these relationships may differ by sex. We hypothesised associations would be apparent between in vivo glutamate and peripheral markers of iron metabolism, and these associations would differ by sex. To test this, we recruited 40 healthy adults (20 men, 20 women) and measured (a) standard clinical biomarker concentrations for iron metabolism and (b) an in vivo proxy for glutamate concentration, glutamate with glutamine in relation to total creatine containing metabolites using proton magnetic resonance spectroscopy studies with a two-dimensional chemical shift imaging slice, with voxels located in bilateral dorsolateral prefrontal cortices, anterior cingulate cortices and frontal white matter. Only the female group reported significant associations between peripheral markers of iron metabolism and Glx:tCr concentration: (a) right dorsolateral prefrontal cortex Glx:tCr associated positively with serum transferrin (r = .60, p = .006) and negatively with transferrin saturation (r = -.62, p = .004) and (b) right frontal white matter Glx:tCr associated negatively with iron concentration (r = -.59, p = .008) and transferrin saturation (r = -.65, p = .002). Our results support associations between iron metabolism and our proxy for in vivo glutamate concentration (Glx:tCr). These associations were limited to women, suggesting a stronger regulatory control between iron and glutamate metabolism. These associations support additional fundamental research into the molecular mechanisms of this regulatory control., (© 2019 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)
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- 2020
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48. CYP19A1 rs10046 Pharmacogenetics in Postmenopausal Breast Cancer Patients Treated with Aromatase Inhibitors: One-year Follow-up.
- Author
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Baatjes K, Peeters A, McCaul M, Conradie MM, Apffelstaedt J, Conradie M, and Kotze MJ
- Subjects
- Aromatase genetics, Bone Density genetics, Female, Follow-Up Studies, Humans, Pharmacogenetics, Polymorphism, Single Nucleotide, Postmenopause, Aromatase Inhibitors adverse effects, Breast Neoplasms drug therapy, Breast Neoplasms genetics
- Abstract
Background: Significant individual variation in bone loss associated with aromatase inhibitors (AIs) emphasizes the importance of identifying postmenopausal breast cancer patients at high risk for this adverse effect. The study explores the clinical relevance of genetic variation in the Cytochrome P450 19A1 (CYP19A1) gene in a subset of South African patients during the first year of taking AIs for estrogen receptor (ER)-positive breast cancer., Methods: The study population consisted of ER-positive breast cancer patients on AIs, followed in real-life clinical practice. Body mass index was measured and bone mineral density (BMD) was determined at baseline and at month 12. CYP19A1 genotyping was performed using real-time polymerase chain reaction analysis of rs10046, extended to Sanger sequencing and whole exome sequencing in 10 patients with more than 5% bone loss at month 12 at the lumbar spine., Results: After 12 months of AI treatment, 72 patients had completed BMD and were successfully genotyped. Ten patients (14%) experienced more than 5% bone loss at the lumbar spine over the study period. Genotyping for CYP19A1 rs10046 revealed that patients with two copies of the A-allele were 10.79 times more likely to have an ordinal category change of having an increased percentage of bone loss or no increase at the lumbar spine, compared to patients with the GA or GG genotypes (CI of 1.771- 65.830, p=0.01). None of the 34 patients without lumbar spine bone loss at month 12 were homozygous for the functional CYP19A1 polymorphism. At the total hip region, patients with the AA genotype were 7. 37 times more likely to have an ordinal category change of having an increased percentage of bone loss or no increase (CI of 1.101- 49.336, p=0.04)., Conclusion: Homozygosity for the CYP19A1 rs10046 A-allele may provide information, in addition to clinical and biochemical factors that may be considered in risk stratification to optimize bone health in postmenopausal breast cancer women on AIs. Further investigation is required to place the clinical effect observed for a single CYP19A1 gene variant in a genomic context., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
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- 2020
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49. A framework for tiered informed consent for health genomic research in Africa.
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Nembaware V, Johnston K, Diallo AA, Kotze MJ, Matimba A, Moodley K, Tangwa GB, Torrorey-Sawe R, and Tiffin N
- Subjects
- Genetic Research legislation & jurisprudence, Humans, Information Dissemination legislation & jurisprudence, Informed Consent legislation & jurisprudence, Biological Specimen Banks ethics, Black People genetics, Genetic Research ethics, Genome, Human, Genomics methods, Information Dissemination ethics, Informed Consent ethics
- Published
- 2019
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50. Baseline bone health status in multi-ethnic South African postmenopausal breast cancer patients at initiation of aromatase inhibitor therapy: A descriptive study.
- Author
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Baatjes KJ, Kotze MJ, McCaul M, and Conradie M
- Subjects
- Aged, Aged, 80 and over, Black People, Body Weight drug effects, Bone Density drug effects, Bone Density Conservation Agents administration & dosage, Bone Diseases, Metabolic chemically induced, Bone and Bones drug effects, Breast Neoplasms complications, Breast Neoplasms pathology, Cohort Studies, Female, Fractures, Bone chemically induced, Fractures, Bone physiopathology, Health Status, Humans, Middle Aged, Osteoporosis, Postmenopausal chemically induced, Osteoporosis, Postmenopausal physiopathology, Postmenopause drug effects, Vitamin D administration & dosage, Aromatase Inhibitors adverse effects, Bone Diseases, Metabolic drug therapy, Breast Neoplasms drug therapy, Fractures, Bone drug therapy, Osteoporosis, Postmenopausal drug therapy
- Abstract
Introduction: Osteoporosis (OP) risk factor assessment and bone mineral density (BMD) testing are frequently omitted at baseline in aromatase inhibitor (AI) studies, which may lead to misinterpretation of AI associated bone loss. The present study describes bone health of South African postmenopausal women of predominantly Mixed Ancestry, prior to AI treatment., Methods: This descriptive baseline study, nested in a prospective AI cohort study, included postmenopausal women with endocrine sensitive breast cancer, aged 50 to 80 years. A baseline questionnaire documented demographic-, medical-, lifestyle- and fracture history. Body weight was assessed clinically, and body composition and BMD measured via dual energy absorptiometry (DXA). Data was analysed in STATA 14 using descriptive and inferential statistics., Results: 101 participants were recruited, with a mean age of 61±7 years. Nearly a third (n = 32) of women at baseline fulfilled global criteria for bone protection (BMD T-score ≥-2SD (n = 18); BMD T-score -1.5SD to < -2SD with risk factors (n = 14). Lower body weight, body mass index (BMI), fat mass index and lean mass index were significantly associated with the participants with a BMD measurement in keeping with a diagnosis of OP (p <0.001). Low vitamin D was present in 93% of the cohort tested (n = 95), whilst deficient vitamin D status (<20ng/ml) was documented in 52 women (55%)., Conclusions: In this study, a third of postmenopausal women considered for AI therapy fulfilled international criteria for bone protective pharmacological intervention. This emphasizes the need for clinical risk and BMD assessment in postmenopausal breast cancer patients at baseline. Body composition and bone health associations highlight bone fragility associated with lower body weight., Competing Interests: Prof. MJ Kotze is a director and shareholder of Gknowmix (Pty) Ltd.
- Published
- 2019
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