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Moore AR, Yu J, Pei Y, Cheng EWY, Taylor Tavares AL, Walker WT, Thomas NS, Kamath A, Ibitoye R, Josifova D, Wilsdon A, Ross A, Calder AD, Offiah AC, Wilkie AOM, Taylor JC, Pagnamenta AT. Use of genome sequencing to hunt for cryptic second-hit variants: analysis of 31 cases recruited to the 100 000 Genomes Project. J Med Genet 2023; 60:1235-1244. [PMID: 37558402 PMCID: PMC10715503 DOI: 10.1136/jmg-2023-109362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 07/28/2023] [Indexed: 08/11/2023]
Abstract
BACKGROUND Current clinical testing methods used to uncover the genetic basis of rare disease have inherent limitations, which can lead to causative pathogenic variants being missed. Within the rare disease arm of the 100 000 Genomes Project (100kGP), families were recruited under the clinical indication 'single autosomal recessive mutation in rare disease'. These participants presented with strong clinical suspicion for a specific autosomal recessive disorder, but only one suspected pathogenic variant had been identified through standard-of-care testing. Whole genome sequencing (WGS) aimed to identify cryptic 'second-hit' variants. METHODS To investigate the 31 families with available data that remained unsolved following formal review within the 100kGP, SVRare was used to aggregate structural variants present in <1% of 100kGP participants. Small variants were assessed using population allele frequency data and SpliceAI. Literature searches and publicly available online tools were used for further annotation of pathogenicity. RESULTS Using these strategies, 8/31 cases were solved, increasing the overall diagnostic yield of this cohort from 10/41 (24.4%) to 18/41 (43.9%). Exemplar cases include a patient with cystic fibrosis harbouring a novel exonic LINE1 insertion in CFTR and a patient with generalised arterial calcification of infancy with complex interlinked duplications involving exons 2-6 of ENPP1. Although ambiguous by short-read WGS, the ENPP1 variant structure was resolved using optical genome mapping and RNA analysis. CONCLUSION Systematic examination of cryptic variants across a multi-disease cohort successfully identifies additional pathogenic variants. WGS data analysis in autosomal recessive rare disease should consider complex structural and small intronic variants as potentially pathogenic second hits.
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Affiliation(s)
- A Rachel Moore
- Wellcome Centre for Human Genetics, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
- Cambridge Genomics Laboratory, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Jing Yu
- Wellcome Centre for Human Genetics, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Yang Pei
- Clinical Genetics Group, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | | | | | - Woolf T Walker
- School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- PCD Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - N Simon Thomas
- Wessex Regional Genetics Laboratory, Salisbury NHS Foundation Trust, Salisbury, UK
| | - Arveen Kamath
- All Wales Medical Genomics Service, University Hospital of Wales, Cardiff, UK
| | - Rita Ibitoye
- North West Thames Regional Genetics Service, Northwick Park Hospital, Harrow, London, UK
| | - Dragana Josifova
- Department of Clinical Genetics, Guy's and St Thomas' Hospitals NHS Trust, London, UK
| | - Anna Wilsdon
- Clinical Genetics, Nottingham City Hospital, Nottingham, UK
| | - Alison Ross
- Clinical Genetics, NHS Grampian, Aberdeen, UK
| | - Alistair D Calder
- Radiology Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Amaka C Offiah
- Department of Oncology and Metabolism, The University of Sheffield, Sheffield, UK
| | - Andrew O M Wilkie
- Clinical Genetics Group, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Jenny C Taylor
- Wellcome Centre for Human Genetics, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Alistair T Pagnamenta
- Wellcome Centre for Human Genetics, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
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Lyulcheva-Bennett E, Genomics England Research Consortium, Bennett D. A retrospective analysis of phosphatase catalytic subunit gene variants in patients with rare disorders identifies novel candidate neurodevelopmental disease genes. Front Cell Dev Biol 2023; 11:1107930. [PMID: 37056996 PMCID: PMC10086149 DOI: 10.3389/fcell.2023.1107930] [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: 11/25/2022] [Accepted: 03/03/2023] [Indexed: 03/30/2023] Open
Abstract
Rare genetic disorders represent some of the most severe and life-limiting conditions that constitute a considerable burden on global healthcare systems and societies. Most individuals affected by rare disorders remain undiagnosed, highlighting the unmet need for improved disease gene discovery and novel variant interpretation. Aberrant (de) phosphorylation can have profound pathological consequences underpinning many disease processes. Numerous phosphatases and associated proteins have been identified as disease genes, with many more likely to have gone undiscovered thus far. To begin to address these issues, we have performed a systematic survey of de novo variants amongst 189 genes encoding phosphatase catalytic subunits found in rare disease patients recruited to the 100,000 Genomes Project (100 kGP), the largest national sequencing project of its kind in the United Kingdom. We found that 49% of phosphatases were found to carry de novo mutation(s) in this cohort. Only 25% of these phosphatases have been previously linked to genetic disorders. A gene-to-patient approach matching variants to phenotypic data identified 9 novel candidate rare-disease genes: PTPRD, PTPRG, PTPRT, PTPRU, PTPRZ1, MTMR3, GAK, TPTE2, PTPN18. As the number of patients undergoing whole genome sequencing increases and information sharing improves, we anticipate that reiterative analysis of genomic and phenotypic data will continue to identify candidate phosphatase disease genes for functional validation. This is the first step towards delineating the aetiology of rare genetic disorders associated with altered phosphatase function, leading to new biological insights and improved clinical outcomes for the affected individuals and their families.
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Affiliation(s)
| | | | - Daimark Bennett
- Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
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Ge R, Cao M, Chen M, Liu M, Xie S. Cytoskeletal networks in primary cilia: Current knowledge and perspectives. J Cell Physiol 2022; 237:3975-3983. [PMID: 36000703 DOI: 10.1002/jcp.30865] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 07/08/2022] [Accepted: 08/11/2022] [Indexed: 11/12/2022]
Abstract
Primary cilia, microtubule-based protrusions present on the surface of most mammalian cells, function as sensory organelles that monitor extracellular signals and transduce them into intracellular biochemical responses. There is renewed research interest in primary cilia due to their essential roles in development, tissue homeostasis, and human diseases. Primary cilia dysfunction causes a large spectrum of human diseases, collectively known as ciliopathies. Despite significant advances in our understanding of primary cilia, there are still no effective agents for treating ciliopathies. Primary ciliogenesis is a highly ordered process involving membrane trafficking, basal body maturation, vesicle docking and fusion, transition zone assembly, and axoneme extension, in which actin and microtubule networks play critical and multiple roles. Actin and microtubule network architecture, isotropy, and dynamics are tightly controlled by cytoskeleton-associated proteins, a growing number of which are now recognized as responsible for cilium formation and maintenance. Here we summarize the roles of actin and microtubules and their associated proteins in primary ciliogenesis and maintenance. In doing so, we highlight that targeting cytoskeleton-associated proteins may be a promising therapeutic strategy for the treatment of ciliopathies.
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Affiliation(s)
- Ruixin Ge
- Department of Cell Biology, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, Shandong Normal University, Jinan, China
| | - Minghui Cao
- Department of Cell Biology, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, Shandong Normal University, Jinan, China
| | - Miao Chen
- Department of Bioscience, School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Min Liu
- Department of Cell Biology, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, Shandong Normal University, Jinan, China
| | - Songbo Xie
- Department of Cell Biology, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, Shandong Normal University, Jinan, China.,Department of Bioscience, School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
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