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Mudau MM, Seymour H, Nevondwe P, Kerr R, Spencer C, Feben C, Lombard Z, Honey E, Krause A, Carstens N. A feasible molecular diagnostic strategy for rare genetic disorders within resource-constrained environments. J Community Genet 2024; 15:39-48. [PMID: 37815686 PMCID: PMC10858011 DOI: 10.1007/s12687-023-00674-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 09/19/2023] [Indexed: 10/11/2023] Open
Abstract
Timely and accurate diagnosis of rare genetic disorders is critical, as it enables improved patient management and prognosis. In a resource-constrained environment such as the South African State healthcare system, the challenge is to design appropriate and cost-effective assays that will enable accurate genetic diagnostic services in patients of African ancestry across a broad disease spectrum. Next-generation sequencing (NGS) has transformed testing approaches for many Mendelian disorders, but this technology is still relatively new in our setting and requires cost-effective ways to implement. As a proof of concept, we describe a feasible diagnostic strategy for genetic disorders frequently seen in our genetics clinics (RASopathies, Cornelia de Lange syndrome, Treacher Collins syndrome, and CHARGE syndrome). The custom-designed targeted NGS gene panel enabled concurrent variant screening for these disorders. Samples were batched during sequencing and analyzed selectively based on the clinical phenotype. The strategy employed in the current study was cost-effective, with sequencing and analysis done at USD849.68 per sample and achieving an overall detection rate of 54.5%. The strategy employed is cost-effective as it allows batching of samples from patients with different diseases in a single run, an approach that can be utilized with rare and less frequently ordered molecular diagnostic tests. The subsequent selective analysis pipeline allowed for timeous reporting back of patients results. This is feasible with a reasonable yield and can be employed for the molecular diagnosis of a wide range of rare monogenic disorders in a resource-constrained environment.
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Affiliation(s)
- Maria Mabyalwa Mudau
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - Heather Seymour
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Patracia Nevondwe
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Robyn Kerr
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Careni Spencer
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Candice Feben
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Zané Lombard
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Engela Honey
- Department of Biochemistry, Genetics and Microbiology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
| | - Amanda Krause
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Nadia Carstens
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Genomics Platform, South African Medical Research Council, Cape Town, South Africa
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2
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Lou J, Chu X, Yang X, Jamil M, Zhu H. Deciphering DNA repair gene mutational landscape in uterine corpus endometrial carcinoma patients using next generation sequencing. Am J Cancer Res 2024; 14:210-226. [PMID: 38323278 PMCID: PMC10839304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 12/25/2023] [Indexed: 02/08/2024] Open
Abstract
Uterine Corpus Endometrial Carcinoma (UCEC) is a significant health concern with a complex genetic landscape impacting disease susceptibility and progression. This study aimed to unravel the spectrum of DNA repair gene mutations in Pakistani UCEC patients through Next Generation Sequencing (NGS) and explore their potential functional consequences via downstream analyses. NGS analysis of genomic DNA from 30 UCEC patients was conducted to identify clinically significant pathogenic mutations in DNA repair genes. This analysis revealed mutations in 4 key DNA repair genes: BRCA1, BRCA2, APC, and CDH1. Kaplan-Meier (KM) analysis was employed to assess the prognostic value of these mutations on patient overall survival (OS) in UCEC. To delve into the functional impact of these mutations, we performed RT-qPCR, immunohistochemistry (IHC), and western blot analyses on the mutated UCEC samples compared to their non-mutated counterparts. These results unveiled the up-regulation in the expression of the mutated genes, suggesting a potential association between the identified mutations and enhanced gene activity. Additionally, targeted bisulfite sequencing analysis was utilized to evaluate DNA methylation patterns in the promoters of the mutated genes. Strikingly, hypomethylation in the promoters of BRCA1, BRCA2, APC, and CDH1 was observed in the mutated UCEC samples relative to the non-mutated, indicating the involvement of epigenetic mechanisms in the altered gene expression. In conclusion, this study offers insights into the genetic landscape of DNA repair gene mutations in Pakistani UCEC patients. The presence of pathogenic mutations in BRCA1, BRCA2, APC, and CDH1, coupled with their down-regulation and hypermethylation, suggests a convergence of genetic and epigenetic factors contributing to genomic instability in UCEC cells. These findings enhance our understanding of UCEC susceptibility and provide potential avenues for targeted therapeutic interventions in Pakistani UCEC patients.
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Affiliation(s)
- Jun Lou
- Department of Gynecological Oncology, Jiangxi Cancer HospitalNanchang 330029, Jiangxi, China
- The Second Affiliated Hospital of Nanchang Medical College, Jiangxi Key Laboratory of Translational Research for CancerNanchang 330029, Jiangxi, China
| | - Xiaoyan Chu
- Department of Gynecological Oncology, Jiangxi Cancer HospitalNanchang 330029, Jiangxi, China
- The Second Affiliated Hospital of Nanchang Medical CollegeNanchang 330029, Jiangxi, China
| | - Xiaorong Yang
- Department of Gynecological Oncology, Jiangxi Cancer HospitalNanchang 330029, Jiangxi, China
- The Second Affiliated Hospital of Nanchang Medical CollegeNanchang 330029, Jiangxi, China
| | - Muhammad Jamil
- PARC Arid Zone Research CenterDera Ismail Khan 29050, Pakistan
| | - Hong Zhu
- Department of Gynecological Oncology, Jiangxi Cancer HospitalNanchang 330029, Jiangxi, China
- The Second Affiliated Hospital of Nanchang Medical CollegeNanchang 330029, Jiangxi, China
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3
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Zhang Y, Ali A, Xie J. Detection of clinically important BRCA gene mutations in ovarian cancer patients using next generation sequencing analysis. Am J Cancer Res 2023; 13:5005-5020. [PMID: 37970354 PMCID: PMC10636669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 10/10/2023] [Indexed: 11/17/2023] Open
Abstract
Ovarian cancer, a complex and aggressive malignancy, remains a significant challenge in clinical oncology due to its heterogeneous nature and limited therapeutic options. In this study, across Pakistani ovarian cancer patients, we conducted a comprehensive analysis of mutations within the BRCA1 and BRCA2 genes to elucidate their potential implications in ovarian cancer susceptibility and progression. Employing Next-Generation Sequencing (NGS), we conducted a comprehensive mutational analysis of BRCA1/2 genes. Kaplan Meier analysis was used to analyze the effect of pathogenic mutations on the survival outcomes of ovarian cancer patients. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Immunohistochemistry (IHC) analyses were conducted to analyze the downstream effect of the pathogenic mutations. Targeted bisulfite sequencing (bisulfite-seq) analysis facilitated the investigation of epigenetic contributions to gene expression regulation. Enrichment analysis was conducted to uncover significant Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways associated with BRCA1/2. Exploring DrugBank, we identified potential drugs capable of modulating BRCA1/2 expression regulation. NGS analysis identified three clinically significant pathogenic mutations within the BRCA1 gene and two within the BRCA2 gene, shedding light on their potential involvement in ovarian cancer susceptibility and progression. Kaplan Meier analysis unveiled poor overall survival (OS) associated with the identified pathogenic mutations, accentuating their prognostic value. Expression analysis using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and IHC demonstrated a significant up-regulation of BRCA1 and BRCA2 genes in ovarian cancer samples harboring pathogenic mutations. Bisulfite-seq revealed a significant hypomethylation within promoter regions of mutated BRCA1 and BRCA2 genes in ovarian cancer samples, compared to non-mutated cases with pathogenic mutations, indicating the role of epigenetics in expression dysregulation as well. By uncovering clinically significant pathogenic mutations in BRCA1/2 genes and establishing their link with up-regulated gene expression, this study significantly advances our understanding of ovarian cancer's underlying causes in the Pakistani population.
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Affiliation(s)
- Yiping Zhang
- School of Life Sciences, Fudan UniversityShanghai 200438, China
| | - Akbar Ali
- Nishtar Medial CollegeMultan 60800, Punjab, Pakistan
| | - Jun Xie
- School of Life Sciences, Fudan UniversityShanghai 200438, China
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4
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Wang L, Ma Y, Han W, Yang Q, Jamil M. Whole Exome Sequencing reveals clinically important pathogenic mutations in DNA repair genes across lung cancer patients. Am J Cancer Res 2023; 13:4989-5004. [PMID: 37970346 PMCID: PMC10636674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Accepted: 09/24/2023] [Indexed: 11/17/2023] Open
Abstract
Lung cancer remains a substantial health challenge, with distinct genetic factors influencing disease susceptibility and progression. This study aimed to decipher the landscape of DNA repair gene mutations in Pakistani lung cancer patients using Whole Exome Sequencing (WES) and to investigate their potential functional implications through downstream analyses. WES analysis of genomic DNA from 15 lung cancer patients identified clinically important pathogenic mutations in 6 DNA repair genes, including, BReast CAncer gene 1 (BRCA1), BReast CAncer gene 2 (BRCA2), Excision Repair Cross Complementing rodent repair deficiency, complementation group 6 (ERCC6), Checkpoint Kinase 1 (CHEK1), mutY DNA glycosylase (MUTYH), and RAD51D (RAD51 Paralog D). Kaplan-Meier (KM) analysis showed that pathogenic mutations in BRCA1, BRCA2, ERCC6, CHEK1, MUTYH, and RAD51D genes were the prognostic biomarkers of worse OS in lung cancer patients. To explore the functional impact of these mutations, we performed Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Immunohistochemistry (IHC) analyses. Our results revealed a down-regulation in the expression of the mutated genes, indicating a potential link between the identified mutations and reduced gene activity. This down-regulation could contribute to compromised DNA repair efficiency, thereby fostering genomic instability in lung cancer cells. Furthermore, targeted bisulfite sequencing analysis was employed to assess the DNA methylation status of the mutated genes. Strikingly, hypermethylation in the promoters of BRCA1, BRCA2, ERCC6, CHEK1, MUTYH, and RAD51D was observed across lung cancer samples harboring pathogenic mutations, suggesting the involvement of epigenetic mechanism underlying the altered gene expression. In conclusion, this study provides insights into the genetic landscape of DNA repair gene mutations in Pakistani lung cancer patients. The observed pathogenic mutations in BRCA1, BRCA2, ERCC6, CHEK1, MUTYH, and RAD51D, coupled with their down-regulation and hypermethylation, suggest a potential convergence of genetic and epigenetic factors driving genomic instability in lung cancer cells. These findings contribute to our understanding of lung cancer susceptibility and highlight potential avenues for targeted therapeutic interventions in Pakistani lung cancer patients.
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Affiliation(s)
- Lanlan Wang
- Department of Medicine, The First People’s Hospital of ShangqiuShangqiu 476100, Henan, China
| | - Yali Ma
- Department of Oncology, Shangqiu First People’s HospitalShangqiu 476000, Henan, China
| | - Wenjie Han
- Department of Oncology, Shangqiu First People’s HospitalShangqiu 476000, Henan, China
| | - Qiumin Yang
- Department of Oncology, Shangqiu First People’s HospitalShangqiu 476000, Henan, China
| | - Muhammad Jamil
- PARC Arid Zone Research CenterDera Ismail Khan 29050, Pakistan
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5
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Htet M, Lei S, Bajpayi S, Zoitou A, Chamakioti M, Tampakakis E. The role of noncoding genetic variants in cardiomyopathy. Front Cardiovasc Med 2023; 10:1116925. [PMID: 37283586 PMCID: PMC10239966 DOI: 10.3389/fcvm.2023.1116925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 05/04/2023] [Indexed: 06/08/2023] Open
Abstract
Cardiomyopathies remain one of the leading causes of morbidity and mortality worldwide. Environmental risk factors and genetic predisposition account for most cardiomyopathy cases. As with all complex diseases, there are significant challenges in the interpretation of the molecular mechanisms underlying cardiomyopathy-associated genetic variants. Given the technical improvements and reduced costs of DNA sequence technologies, an increasing number of patients are now undergoing genetic testing, resulting in a continuously expanding list of novel mutations. However, many patients carry noncoding genetic variants, and although emerging evidence supports their contribution to cardiac disease, their role in cardiomyopathies remains largely understudied. In this review, we summarize published studies reporting on the association of different types of noncoding variants with various types of cardiomyopathies. We focus on variants within transcriptional enhancers, promoters, intronic sites, and untranslated regions that are likely associated with cardiac disease. Given the broad nature of this topic, we provide an overview of studies that are relatively recent and have sufficient evidence to support a significant degree of causality. We believe that more research with additional validation of noncoding genetic variants will provide further mechanistic insights on the development of cardiac disease, and noncoding variants will be increasingly incorporated in future genetic screening tests.
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Affiliation(s)
- Myo Htet
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD, United States
| | - Shunyao Lei
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States
| | - Sheetal Bajpayi
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD, United States
| | - Asimina Zoitou
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States
| | | | - Emmanouil Tampakakis
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD, United States
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States
- Department of Genetic Medicine, Johns Hopkins University, Baltimore, MD, United States
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6
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Fan Y, Zhou Y, Liu H, Luo X, Xu T, Sun Y, Yang T, Chen L, Gu X, Yu Y. Improving variant prioritization in exome analysis by entropy-weighted ensemble of multiple tools. Clin Genet 2023; 103:190-199. [PMID: 36309956 DOI: 10.1111/cge.14257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/09/2022] [Accepted: 10/22/2022] [Indexed: 01/07/2023]
Abstract
Variant prioritization is a crucial step in the analysis of exome and genome sequencing. Multiple phenotype-driven tools have been developed to automate the variant prioritization process, but the efficacy of these tools in clinical setting with fuzzy phenotypic information and whether ensemble of these tools could outperform single algorithm remains to be assessed. A large rare disease cohort with heterogeneous phenotypic information, including a primary cohort of 1614 patients and a replication cohort of 1904 patients referred to exome sequencing, were recruited to assess the efficacy of variant prioritization and their ensemble. Three freely available tools-Exomiser, Xrare, and DeepPVP-and their ensemble were evaluated. The performance of all three tools was influenced by the attributes of phenotypic input. When combining these three tools by weighted-sum entropy method (EWE3), the ensemble outperformed any single algorithm, achieving a rate of 78% diagnostic variants in top 3 (13% improvement over current best performer, compared to Exomiser: 63%, Xrare: 65%, and DeepPVP: 51%), 88% in top 10 and 96% in top 30. The results were replicated in another independent cohort. Our study supports using entropy-weighted ensemble of multiple tools to improve variant prioritization and accelerate molecular diagnosis in exome/genome sequencing.
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Affiliation(s)
- Yanjie Fan
- Shanghai Institute of Pediatric Research, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | | | - Huili Liu
- Shanghai Institute of Pediatric Research, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xiaomei Luo
- Shanghai Institute of Pediatric Research, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Ting Xu
- Shanghai Institute of Pediatric Research, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yu Sun
- Shanghai Institute of Pediatric Research, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Tingting Yang
- Shanghai Institute of Pediatric Research, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Linlin Chen
- Shanghai Institute of Pediatric Research, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xuefan Gu
- Shanghai Institute of Pediatric Research, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yongguo Yu
- Shanghai Institute of Pediatric Research, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
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7
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Oluwole OG, Henry M. Genomic medicine in Africa: a need for molecular genetics and pharmacogenomics experts. Curr Med Res Opin 2023; 39:141-147. [PMID: 36094413 DOI: 10.1080/03007995.2022.2124072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The large-scale implementation of genomic medicine in Africa has not been actualized. This overview describes how routine molecular genetics and advanced protein engineering/structural biotechnology could accelerate the implementation of genomic medicine. By using data-mining and analysis approaches, we analyzed relevant information obtained from public genomic databases on pharmacogenomics biomarkers and reviewed published studies to discuss the ideas. The results showed that only 68 very important pharmacogenes currently exist, while 867 drug label annotations, 201 curated functional pathways, and 746 annotated drugs have been catalogued on the largest pharmacogenomics database (PharmGKB). Only about 5009 variants of the reported ∼25,000 have been clinically annotated. Predominantly, the genetic variants were derived from 43 genes that contribute to 2318 clinically relevant variations in 57 diseases. Majority (∼60%) of the clinically relevant genetic variations in the pharmacogenes are missense variants (1390). The enrichment analysis showed that 15 pharmacogenes are connected biologically and are involved in the metabolism of cardiovascular and cancer drugs. The review of studies showed that cardiovascular diseases are the most frequent non-communicable diseases responsible for approximately 13% of all deaths in Africa. Also, warfarin pharmacogenomics is the most studied drug on the continent, while CYP2D6, CYP2C9, DPD, and TPMT are the most investigated pharmacogenes with allele activities indicated in African and considered to be intermediate metaboliser for DPD and TPMT (8.4% and 11%). In summary, we highlighted a framework for implementing genomic medicine starting from the available resources on ground.
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Affiliation(s)
- Oluwafemi G Oluwole
- Division of Human Genetics, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Marc Henry
- Medical Biotechnology and Immunotherapy Unit, Department of Integrative Biomedical Sciences Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
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Marian AJ. Sporadic dilated cardiomyopathy is often familial. Cardiovasc Res 2022; 118:e69-e71. [PMID: 35726845 PMCID: PMC9890628 DOI: 10.1093/cvr/cvac075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- Ali J Marian
- Corresponding author. Tel: +1 713 500 2350, E-mail:
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9
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Liu Z, Roberts R, Mercer TR, Xu J, Sedlazeck FJ, Tong W. Towards accurate and reliable resolution of structural variants for clinical diagnosis. Genome Biol 2022; 23:68. [PMID: 35241127 PMCID: PMC8892125 DOI: 10.1186/s13059-022-02636-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 02/15/2022] [Indexed: 12/17/2022] Open
Abstract
Structural variants (SVs) are a major source of human genetic diversity and have been associated with different diseases and phenotypes. The detection of SVs is difficult, and a diverse range of detection methods and data analysis protocols has been developed. This difficulty and diversity make the detection of SVs for clinical applications challenging and requires a framework to ensure accuracy and reproducibility. Here, we discuss current developments in the diagnosis of SVs and propose a roadmap for the accurate and reproducible detection of SVs that includes case studies provided from the FDA-led SEquencing Quality Control Phase II (SEQC-II) and other consortium efforts.
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Affiliation(s)
- Zhichao Liu
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Ruth Roberts
- ApconiX, BioHub at Alderley Park, Alderley Edge, SK10 4TG, UK.,University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Timothy R Mercer
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane, QLD, Australia.,Garvan Institute of Medical Research, Sydney, NSW, Australia.,St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Joshua Xu
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Fritz J Sedlazeck
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
| | - Weida Tong
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA.
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10
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Ben-Haim Y, Behr ER. Genetics of sudden cardiac death. Curr Opin Cardiol 2022; 37:212-218. [DOI: 10.1097/hco.0000000000000946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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11
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Nöthen MM, Erdmann J, Schlegelberger B, Kornak U. Wie wichtig ist die Kenntnis des genetischen Populationshintergrundes in der Medizin? Ein humangenetischer Beitrag vor dem Hintergrund der aktuellen Diskussion um die Verwendung des Begriffs „Rasse“. MED GENET-BERLIN 2022. [DOI: 10.1515/medgen-2021-2106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Markus M. Nöthen
- Institut für Humangenetik , Universitätsklinikum Bonn , Venusberg-Campus 1 , Bonn , Deutschland
| | - Jeanette Erdmann
- Institut für Kardiogenetik , Universität zu Lübeck , Ratzeburger Allee 160 , , Lübeck , Deutschland
| | - Brigitte Schlegelberger
- Institut für Humangenetik , Medizinische Hochschule Hannover , Carl-Neuberg-Str. 1 , Hannover , Deutschland
| | - Uwe Kornak
- Institut für Humangenetik , Universitätsmedizin Göttingen , Heinrich-Düker-Weg 12 , Göttingen , Deutschland
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12
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Kim KH, Pereira NL. Genetics of Cardiomyopathy: Clinical and Mechanistic Implications for Heart Failure. Korean Circ J 2021; 51:797-836. [PMID: 34327881 PMCID: PMC8484993 DOI: 10.4070/kcj.2021.0154] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 06/14/2021] [Indexed: 11/11/2022] Open
Abstract
Genetic cardiomyopathies are an important cause of sudden cardiac death across all age groups. Genetic testing in heart failure clinics is useful for family screening and providing individual prognostic insight. Obtaining a family history of at least three generations, including the creation of a pedigree, is recommended for all patients with primary cardiomyopathy. Additionally, when appropriate, consultation with a genetic counsellor can aid in the success of a genetic evaluation. Clinical screening should be performed on all first-degree relatives of patients with genetic cardiomyopathy. Genetics has played an important role in the understanding of different cardiomyopathies, and the field of heart failure (HF) genetics is progressing rapidly. Much research has also focused on distinguishing markers of risk in patients with cardiomyopathy using genetic testing. While these efforts currently remain incomplete, new genomic technologies and analytical strategies provide promising opportunities to further explore the genetic architecture of cardiomyopathies, afford insight into the early manifestations of cardiomyopathy, and help define the molecular pathophysiological basis for cardiac remodeling. Cardiovascular physicians should be fully aware of the utility and potential pitfalls of incorporating genetic test results into pre-emptive treatment strategies for patients in the preliminary stages of HF. Future work will need to be directed towards elucidating the biological mechanisms of both rare and common gene variants and environmental determinants of plasticity in the genotype-phenotype relationship. This future research should aim to further our ability to identify, diagnose, and treat disorders that cause HF and sudden cardiac death in young patients, as well as prioritize improving our ability to stratify the risk for these patients prior to the onset of the more severe consequences of their disease.
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Affiliation(s)
- Kyung Hee Kim
- Division of Cardiology, Incheon Sejong General Hospital, Incheon, Korea.
| | - Naveen L Pereira
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
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13
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Abstract
Hypertrophic cardiomyopathy (HCM) is a genetic disease of the myocardium characterized by a hypertrophic left ventricle with a preserved or increased ejection fraction. Cardiac hypertrophy is often asymmetrical, which is associated with left ventricular outflow tract obstruction. Myocyte hypertrophy, disarray, and myocardial fibrosis constitute the histological features of HCM. HCM is a relatively benign disease but an important cause of sudden cardiac death in the young and heart failure in the elderly. Pathogenic variants (PVs) in genes encoding protein constituents of the sarcomeres are the main causes of HCM. PVs exhibit a gradient of effect sizes, as reflected in their penetrance and variable phenotypic expression of HCM. MYH7 and MYBPC3, encoding β-myosin heavy chain and myosin binding protein C, respectively, are the two most common causal genes and responsible for ≈40% of all HCM cases but a higher percentage of HCM in large families. PVs in genes encoding protein components of the thin filaments are responsible for ≈5% of the HCM cases. Whereas pathogenicity of the genetic variants in large families has been firmly established, ascertainment causality of the PVs in small families and sporadic cases is challenging. In the latter category, PVs are best considered as probabilistic determinants of HCM. Deciphering the genetic basis of HCM has enabled routine genetic testing and has partially elucidated the underpinning mechanism of HCM as increased number of the myosin molecules that are strongly bound to actin. The discoveries have led to the development of mavacamten that targets binding of the myosin molecule to actin filaments and imparts beneficial clinical effects. In the coming years, the yield of the genetic testing is expected to be improved and the so-called missing causal gene be identified. The advances are also expected to enable development of additional specific therapies and editing of the mutations in HCM.
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Affiliation(s)
- A J Marian
- Center for Cardiovascular Genetics, Institute of Molecular Medicine and Department of Medicine, University of Texas Health Sciences Center at Houston
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14
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Abstract
PURPOSE OF REVIEW Atrial fibrillation is the most common sustained cardiac arrhythmia. In addition to traditional risk factors, it is increasingly recognized that a genetic component underlies atrial fibrillation development. This review aims to provide an overview of the genetic cause of atrial fibrillation and clinical applications, with a focus on recent developments. RECENT FINDINGS Genome-wide association studies have now identified around 140 genetic loci associated with atrial fibrillation. Studies into the effects of several loci and their tentative gene targets have identified novel pathways associated with atrial fibrillation development. However, further validations of causality are still needed for many implicated genes. Genetic variants at identified loci also help predict individual atrial fibrillation risk and response to different therapies. SUMMARY Continued advances in the field of genetics and molecular biology have led to significant insight into the genetic underpinnings of atrial fibrillation. Potential clinical applications of these studies include the identification of new therapeutic targets and development of genetic risk scores to optimize management of this common cardiac arrhythmia.
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Affiliation(s)
- Jitae A. Kim
- Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Mihail G. Chelu
- Department of Cardiology, Baylor College of Medicine, Houston, TX, USA
| | - Na Li
- Department of Medicine (Section of Cardiovascular Research), Baylor College of Medicine, Houston, TX
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX
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15
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Barp A, Mosca L, Sansone VA. Facilitations and Hurdles of Genetic Testing in Neuromuscular Disorders. Diagnostics (Basel) 2021; 11:diagnostics11040701. [PMID: 33919863 PMCID: PMC8070835 DOI: 10.3390/diagnostics11040701] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/11/2021] [Accepted: 04/12/2021] [Indexed: 12/11/2022] Open
Abstract
Neuromuscular disorders (NMDs) comprise a heterogeneous group of disorders that affect about one in every thousand individuals worldwide. The vast majority of NMDs has a genetic cause, with about 600 genes already identified. Application of genetic testing in NMDs can be useful for several reasons: correct diagnostic definition of a proband, extensive familial counselling to identify subjects at risk, and prenatal diagnosis to prevent the recurrence of the disease; furthermore, identification of specific genetic mutations still remains mandatory in some cases for clinical trial enrollment where new gene therapies are now approaching. Even though genetic analysis is catching on in the neuromuscular field, pitfalls and hurdles still remain and they should be taken into account by clinicians, as for example the use of next generation sequencing (NGS) where many single nucleotide variants of “unknown significance” can emerge, complicating the correct interpretation of genotype-phenotype relationship. Finally, when all efforts in terms of molecular analysis have been carried on, a portion of patients affected by NMDs still remain “not genetically defined”. In the present review we analyze the evolution of genetic techniques, from Sanger sequencing to NGS, and we discuss “facilitations and hurdles” of genetic testing which must always be balanced by clinicians, in order to ensure a correct diagnostic definition, but taking always into account the benefit that the patient could obtain especially in terms of “therapeutic offer”.
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Affiliation(s)
- Andrea Barp
- The NEMO Clinical Center in Milan, Neurorehabilitation Unit, University of Milan, Piazza Ospedale Maggiore 3, 20162 Milano, Italy;
- Correspondence:
| | - Lorena Mosca
- Medical Genetics Unit, ASST Grande Ospedale Metropolitano Niguarda, Piazza Ospedale Maggiore 3, 20162 Milano, Italy;
| | - Valeria Ada Sansone
- The NEMO Clinical Center in Milan, Neurorehabilitation Unit, University of Milan, Piazza Ospedale Maggiore 3, 20162 Milano, Italy;
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Abstract
Neuromuscular disorders (NMDs) comprise a heterogeneous group of disorders that affect about one in every thousand individuals worldwide. The vast majority of NMDs has a genetic cause, with about 600 genes already identified. Application of genetic testing in NMDs can be useful for several reasons: correct diagnostic definition of a proband, extensive familial counselling to identify subjects at risk, and prenatal diagnosis to prevent the recurrence of the disease; furthermore, identification of specific genetic mutations still remains mandatory in some cases for clinical trial enrollment where new gene therapies are now approaching. Even though genetic analysis is catching on in the neuromuscular field, pitfalls and hurdles still remain and they should be taken into account by clinicians, as for example the use of next generation sequencing (NGS) where many single nucleotide variants of "unknown significance" can emerge, complicating the correct interpretation of genotype-phenotype relationship. Finally, when all efforts in terms of molecular analysis have been carried on, a portion of patients affected by NMDs still remain "not genetically defined". In the present review we analyze the evolution of genetic techniques, from Sanger sequencing to NGS, and we discuss "facilitations and hurdles" of genetic testing which must always be balanced by clinicians, in order to ensure a correct diagnostic definition, but taking always into account the benefit that the patient could obtain especially in terms of "therapeutic offer".
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Affiliation(s)
- Andrea Barp
- The NEMO Clinical Center in Milan, Neurorehabilitation Unit, University of Milan, Piazza Ospedale Maggiore 3, 20162 Milano, Italy
| | - Lorena Mosca
- Medical Genetics Unit, ASST Grande Ospedale Metropolitano Niguarda, Piazza Ospedale Maggiore 3, 20162 Milano, Italy
| | - Valeria Ada Sansone
- The NEMO Clinical Center in Milan, Neurorehabilitation Unit, University of Milan, Piazza Ospedale Maggiore 3, 20162 Milano, Italy
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Current knowledge on genetic variants shaping placental transcriptome and their link to gestational and postnatal health. Placenta 2021; 116:2-11. [PMID: 33663810 DOI: 10.1016/j.placenta.2021.02.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 01/15/2021] [Accepted: 02/16/2021] [Indexed: 12/12/2022]
Abstract
Despite the indispensable role of the placenta in the successful course of pregnancy, regulation of its dynamic transcriptome is still underexplored. The purpose of this literature review was to give an overview and draw attention to the contribution of genetic variation in shaping the human placental gene expression. Studies of placental transcriptome shaped by chromosomal variants are limited and may be confounded by cellular mosaicism and somatic genomic rearrangements. Even in relatively simple cases, such as aneuploidies, the placental transcriptome appears to differ from the assumed systematically increased transcript levels of the involved chromosomes. Single nucleotide variants modulating placental gene expression referred to as expression quantitative trait loci (eQTLs) have been analyzed only in ten candidate gene and three genome-wide association studies (GWAS). The latter identified 417 confident placental eGenes, supported by at least two independent studies. Functional profiling of eGenes highlighted biological pathways important in pregnancy, such as immune response or transmembrane transport activity. A fraction of placental eQTLs (1-3%) co-localize with GWAS loci for adult disorders (metabolic, immunological, neurological), suggesting a co-contributory role of the placenta in the developmental programming of health. Some placental eQTLs have been identified as risk factors for adverse pregnancy outcomes, such as rs4769613 (C > T), located near the FLT1 gene and confidently associated with preeclampsia. More studies are needed to map genetic variants shaping gene expression in different placental cell types across three trimesters in normal and complicated gestations and to clarify to what extent these heritable factors contribute to maternal and offspring disease risks.
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