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Bhimma R, Jembere E, Hariparshad S. Case report of a child with nephronophthisis from South Africa. BMC Pediatr 2024; 24:431. [PMID: 38965466 PMCID: PMC11225275 DOI: 10.1186/s12887-024-04872-2] [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] [Received: 09/25/2023] [Accepted: 06/05/2024] [Indexed: 07/06/2024] Open
Abstract
BACKGROUND Nephronophthisis (NPHP) is an autosomal recessive disorder with a subset of patients presenting with extrarenal manifestations such as retinal degeneration, cerebella ataxia, liver fibrosis, skeletal abnormalities, cardiac malformations, and lung bronchiectasis. However, the involvement of other organ systems has also been documented. Extrarenal manifestations occur in approximately 10-20% of patients. In developed countries, it has been reported as one of the most common causes of monogenic chronic kidney failure (CKF) during the first three decades of life, with more than 25 genes associated with this condition. The current treatment options for managing NPHP include supportive care, management of complications, and kidney replacement therapy when necessary. The index patient is a 10-year-old Caucasian female who presented with recurrent attacks of abdominal pain. Her elder sister, TN, who was 17 years old, was diagnosed with CKF and noted to have persistently elevated liver enzymes (gamma-glutamyl transferase, alanine, and aspartate transaminases). Following genetic testing, her elder sister was shown to have Nephronophthisis Type 3, and a liver biopsy showed early fibrotic changes. Subsequent genetic testing confirmed the index patient as having NPHP Type 3. A kidney biopsy showed focal sclerosed glomeruli with patchy areas of tubular atrophy and related tubulointerstitial changes in keeping with NPHP. We present the first confirmatory case of NPHP from South Africa based on histopathology and genetic testing in a 10-year-old Caucasian female who presented with recurrent attacks of abdominal pain, whose elder sister also presented with CKF and early liver fibrosis, confirmed on biopsy and genetic testing. CONCLUSION In low-middle-income countries, genetic testing should be undertaken whenever possible to confirm the diagnosis of NPHP, especially in those with a suggestive biopsy or if there is CKF of unknown aetiology with or without extra-renal manifestations.
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Affiliation(s)
- Rajendra Bhimma
- Department of Paediatrics and Child Health, College of Health Sciences, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.
| | - Edgar Jembere
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Durban, South Africa
| | - Sudesh Hariparshad
- Department of Nephrology, College of Health Sciences, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
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2
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Li ZL, Wang FM, Wen Y, Ni HF, Zhang XL, Wang B. Renal cell carcinoma in an adult-onset ESRD patient with nephronophthisis harboring NPHP3 deletion: A case report. Heliyon 2024; 10:e28985. [PMID: 38617907 PMCID: PMC11015401 DOI: 10.1016/j.heliyon.2024.e28985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 03/12/2024] [Accepted: 03/27/2024] [Indexed: 04/16/2024] Open
Abstract
Background Nephronophthisis (NPHP) is a rare autosomal recessive inherited tubulointerstitial nephropathy, the most prevalent genetic cause of end-stage renal disease (ESRD) in children. Convincing evidence indicated that the overall prevalence of NPHP in adult-onset ESRD is very likely to be an underestimation. Therefore, understanding the genetic background and clinicopathologic features of adult-onset NPHP is warranted. Case presentation we reported one intriguing case with concurrent NPHP3 c.2694-2_2694-1delAG (splicing) variant and c.1082C > G (p.S361C) variant. A 48-year-old male was admitted to our hospital, complained about renal dysfunction for 10 years, and found right renal space-occupying lesion for 1 week. One of the most interesting clinical features is adult-onset ESRD, which differs from previous cases. Another discovery of this study is that the NPHP harboring NPHP3 deletion may be associated with clear cell renal cell carcinoma. Conclusion In conclusion, we report two mutations in the NPHP3 gene that cause NPHP with adult-onset ESRD and renal clear cell carcinoma in a Chinese family, enriching the clinical features of NPHP.
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Affiliation(s)
- Zuo-Lin Li
- Department of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Feng-Mei Wang
- Department of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Yi Wen
- Department of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Hai-Feng Ni
- Department of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Xiao-Liang Zhang
- Department of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Bin Wang
- Department of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
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Devlin L, Dhondurao Sudhindar P, Sayer JA. Renal ciliopathies: promising drug targets and prospects for clinical trials. Expert Opin Ther Targets 2023; 27:325-346. [PMID: 37243567 DOI: 10.1080/14728222.2023.2218616] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/12/2023] [Accepted: 05/23/2023] [Indexed: 05/29/2023]
Abstract
INTRODUCTION Renal ciliopathies represent a collection of genetic disorders characterized by deficiencies in the biogenesis, maintenance, or functioning of the ciliary complex. These disorders, which encompass autosomal dominant polycystic kidney disease (ADPKD), autosomal recessive polycystic kidney disease (ARPKD), and nephronophthisis (NPHP), typically result in cystic kidney disease, renal fibrosis, and a gradual deterioration of kidney function, culminating in kidney failure. AREAS COVERED Here we review the advances in basic science and clinical research into renal ciliopathies which have yielded promising small compounds and drug targets, within both preclinical studies and clinical trials. EXPERT OPINION Tolvaptan is currently the sole approved treatment option available for ADPKD patients, while no approved treatment alternatives exist for ARPKD or NPHP patients. Clinical trials are presently underway to evaluate additional medications in ADPKD and ARPKD patients. Based on preclinical models, other potential therapeutic targets for ADPKD, ARPKD, and NPHP look promising. These include molecules targeting fluid transport, cellular metabolism, ciliary signaling and cell-cycle regulation. There is a real and urgent clinical need for translational research to bring novel treatments to clinical use for all forms of renal ciliopathies to reduce kidney disease progression and prevent kidney failure.
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Affiliation(s)
- Laura Devlin
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - Praveen Dhondurao Sudhindar
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - John A Sayer
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
- Renal Services, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle Upon Tyne, UK
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4
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Sarkar A, Panati K, Narala VR. Code inside the codon: The role of synonymous mutations in regulating splicing machinery and its impact on disease. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2022; 790:108444. [PMID: 36307006 DOI: 10.1016/j.mrrev.2022.108444] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 10/10/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022]
Abstract
In eukaryotes, precise pre-mRNA processing, including alternative splicing, is essential to carry out the intricate protein translation process. Both point mutations (that alter the translated protein sequence) and synonymous mutations (that do not alter the translated protein sequence) are capable of affecting the splicing process. Synonymous mutations are known to affect gene expression via altering mRNA stability, mRNA secondary structure, splicing processes, and translational kinetics. In higher eukaryotes, precise splicing is regulated by three weakly conserved cis-elements, 5' and 3' splice sites and the branch site. Many other cis-acting elements (exonic/intronic splicing enhancers and silencers) and trans-acting splicing factors (serine and arginine-rich proteins and heterogeneous nuclear ribonucleoproteins) have also been found to enhance or suppress the splicing process. The appearance of synonymous mutations in cis-acting elements can alter the splicing process by changing the binding pattern of splicing factors to exonic splicing enhancers or silencer motifs. This results in exon skipping, intron retention, and various other forms of alternative splicing, eventually leading to the emergence of a wide range of diseases. The focus of this review is to elucidate the role of synonymous mutations and their impact on abnormal splicing mechanisms. Further, this study highlights the function of synonymous mutation in mediating abnormal splicing in cancer and development of X-linked, and autosomal inherited diseases.
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Affiliation(s)
- Avik Sarkar
- Department of Zoology, Vidyasagar University, Midnapore, West Bengal 721102, India
| | - Kalpana Panati
- Department of Biotechnology, Government College for Men, Kadapa 516004, India
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König JC, Karsay R, Gerß J, Schlingmann KP, Dahmer-Heath M, Telgmann AK, Kollmann S, Ariceta G, Gillion V, Bockenhauer D, Bertholet-Thomas A, Mastrangelo A, Boyer O, Lilien M, Decramer S, Schanstra J, Pohl M, Schild R, Weber S, Hoefele J, Drube J, Cetiner M, Hansen M, Thumfart J, Tönshoff B, Habbig S, Liebau MC, Bald M, Bergmann C, Pennekamp P, Konrad M. Refining Kidney Survival in 383 Genetically Characterized Patients With Nephronophthisis. Kidney Int Rep 2022; 7:2016-2028. [PMID: 36090483 PMCID: PMC9459005 DOI: 10.1016/j.ekir.2022.05.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 05/30/2022] [Indexed: 11/26/2022] Open
Abstract
Introduction Nephronophthisis (NPH) comprises a group of rare disorders accounting for up to 10% of end-stage kidney disease (ESKD) in children. Prediction of kidney prognosis poses a major challenge. We assessed differences in kidney survival, impact of variant type, and the association of clinical characteristics with declining kidney function. Methods Data was obtained from 3 independent sources, namely the network for early onset cystic kidney diseases clinical registry (n = 105), an online survey sent out to the European Reference Network for Rare Kidney Diseases (n = 60), and a literature search (n = 218). Results A total of 383 individuals were available for analysis: 116 NPHP1, 101 NPHP3, 81 NPHP4 and 85 NPHP11/TMEM67 patients. Kidney survival differed between the 4 cohorts with a highly variable median age at onset of ESKD as follows: NPHP3, 4.0 years (interquartile range 0.3–12.0); NPHP1, 13.5 years (interquartile range 10.5–16.5); NPHP4, 16.0 years (interquartile range 11.0–25.0); and NPHP11/TMEM67, 19.0 years (interquartile range 8.7–28.0). Kidney survival was significantly associated with the underlying variant type for NPHP1, NPHP3, and NPHP4. Multivariate analysis for the NPHP1 cohort revealed growth retardation (hazard ratio 3.5) and angiotensin-converting enzyme inhibitor (ACEI) treatment (hazard ratio 2.8) as 2 independent factors associated with an earlier onset of ESKD, whereas arterial hypertension was linked to an accelerated glomerular filtration rate (GFR) decline. Conclusion The presented data will enable clinicians to better estimate kidney prognosis of distinct patients with NPH and thereby allow personalized counseling.
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Agonists of prostaglandin E 2 receptors as potential first in class treatment for nephronophthisis and related ciliopathies. Proc Natl Acad Sci U S A 2022; 119:e2115960119. [PMID: 35482924 PMCID: PMC9170064 DOI: 10.1073/pnas.2115960119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
SignificanceJuvenile nephronophthisis (NPH) is a renal ciliopathy due to a dysfunction of primary cilia for which no curative treatment is available. This paper describes the identification of agonists of prostaglandin E2 receptors as a potential therapeutic approach for the most common NPHP1-associated ciliopathies. We demonstrated that prostaglandin E1 rescues defective ciliogenesis and ciliary composition in NPHP1 patient urine-derived renal tubular cells and improves ciliary and kidney phenotypes in our NPH zebrafish and Nphp1-/- mouse models. In addition, Taprenepag alleviates the severe retinopathy observed in Nphp1-/- mice. Finally, transcriptomic analyses pointed out several pathways downstream the prostaglandin receptors as cell cycle progression, extracellular matrix, or actin cytoskeleton organization. Altogether, our findings provide an alternative for treatment of NPH.
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7
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Ziegler WH, Lüdiger S, Hassan F, Georgiadis ME, Swolana K, Khera A, Mertens A, Franke D, Wohlgemuth K, Dahmer-Heath M, König J, Dafinger C, Liebau MC, Cetiner M, Bergmann C, Soetje B, Haffner D. Primary URECs: a source to better understand the pathology of renal tubular epithelia in pediatric hereditary cystic kidney diseases. Orphanet J Rare Dis 2022; 17:122. [PMID: 35264234 PMCID: PMC8905910 DOI: 10.1186/s13023-022-02265-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 02/20/2022] [Indexed: 11/24/2022] Open
Abstract
Background In pediatric hereditary cystic kidney diseases, epithelial cell defects mostly result from rare, autosomal recessively inherited pathogenic variants in genes encoding proteins of the cilia-centrosome complex. Consequences of individual gene variants on epithelial function are often difficult to predict and can furthermore depend on the patient’s genetic background. Here, we studied urine-derived renal tubular epithelial cells (URECs) from genetically determined, pediatric cohorts of different hereditary cystic kidney diseases, comprising autosomal recessive polycystic kidney disease, nephronophthisis (NPH) and the Bardet Biedl syndrome (BBS). UREC characteristics and behavior in epithelial function-related 3D cell culture were compared in order to identify gene and variant-specific properties and to determine aspects of epithelial (cell) dysfunction. Results UREC preparations from patients (19) and healthy controls (39) were studied in a qualitative and quantitative manner using primary cells cultured for up-to 21 days. In patients with biallelic pathogenic variants in PKHD1 or NPHP genes, we were able to receive satisfactory amounts of URECs of reproducible quality. In BBS patients, UREC yield was lower and more dependent on the individual genotype. In contrast, in UREC preparations derived from healthy controls, no predictable and satisfactory outcome could be established. Considering cell proliferation, tubular origin and epithelial properties in 2D/3D culture conditions, we observed distinct and reproducible epithelial properties of URECs. In particular, the cells from patients carrying PKHD1 variants were characterized by a high incidence of defective morphogenesis of monolayered spheroids—a property proposed to be suitable for corrective intervention. Furthermore, we explored different ways to generate reference cell lines for both—patients and healthy controls—in order to eliminate restrictions in cell number and availability of primary URECs. Conclusions Ex vivo 3D cell culture of primary URECs represents a valuable, non-invasive source to evaluate epithelial cell function in kidney diseases and as such helps to elucidate the functional consequences of rare genetic disorders. In combination with genetically defined control cell lines to be generated in the future, the cultivation of primary URECs could become a relevant tool for testing personalized treatment of epithelial dysfunction in patients with hereditary cystic kidney disease. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-022-02265-1.
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Affiliation(s)
- Wolfgang H Ziegler
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany.
| | - Sarah Lüdiger
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Fatima Hassan
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Margarita E Georgiadis
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Kathrin Swolana
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Amrit Khera
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Arne Mertens
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Doris Franke
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Kai Wohlgemuth
- Department of General Pediatrics, University Children's Hospital Münster, Münster, Germany
| | - Mareike Dahmer-Heath
- Department of General Pediatrics, University Children's Hospital Münster, Münster, Germany
| | - Jens König
- Department of General Pediatrics, University Children's Hospital Münster, Münster, Germany
| | - Claudia Dafinger
- Department of Pediatrics and Center for Molecular Medicine, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany.,Center for Rare Diseases, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Max C Liebau
- Department of Pediatrics and Center for Molecular Medicine, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany.,Center for Rare Diseases, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Metin Cetiner
- Department of Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | - Carsten Bergmann
- Department of Medicine IV, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany.,Medizinische Genetik Mainz, Mainz, Germany
| | - Birga Soetje
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany.,Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
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Pollara L, Sottile V, Valente EM. Patient-derived cellular models of primary ciliopathies. J Med Genet 2022; 59:517-527. [DOI: 10.1136/jmedgenet-2021-108315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/21/2022] [Indexed: 11/09/2022]
Abstract
Primary ciliopathies are rare inherited disorders caused by structural or functional defects in the primary cilium, a subcellular organelle present on the surface of most cells. Primary ciliopathies show considerable clinical and genetic heterogeneity, with disruption of over 100 genes causing the variable involvement of several organs, including the central nervous system, kidneys, retina, skeleton and liver. Pathogenic variants in one and the same gene may associate with a wide range of ciliopathy phenotypes, supporting the hypothesis that the individual genetic background, with potential additional variants in other ciliary genes, may contribute to a mutational load eventually determining the phenotypic manifestations of each patient. Functional studies in animal models have uncovered some of the pathophysiological mechanisms linking ciliary gene mutations to the observed phenotypes; yet, the lack of reliable human cell models has previously limited preclinical research and the development of new therapeutic strategies for primary ciliopathies. Recent technical advances in the generation of patient-derived two-dimensional (2D) and three-dimensional (3D) cellular models give a new spur to this research, allowing the study of pathomechanisms while maintaining the complexity of the genetic background of each patient, and enabling the development of innovative treatments to target specific pathways. This review provides an overview of available models for primary ciliopathies, from existing in vivo models to more recent patient-derived 2D and 3D in vitro models. We highlight the advantages of each model in understanding the functional basis of primary ciliopathies and facilitating novel regenerative medicine, gene therapy and drug testing strategies for these disorders.
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9
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Choi M, Rübsam A, Schulz M, Decker E, Friedrich A, Schrezenmeier E, Halleck F, Eckardt KU, Bergmann C. Interstitial nephritis - A Change in Diagnosis with Next Generation Sequencing. Kidney Int Rep 2022; 7:1128-1130. [PMID: 35571004 PMCID: PMC9091579 DOI: 10.1016/j.ekir.2022.01.1061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/16/2022] [Accepted: 01/24/2022] [Indexed: 10/25/2022] Open
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Barroso‐Gil M, Olinger E, Ramsbottom SA, Molinari E, Miles CG, Sayer JA. Update of genetic variants in CEP120 and CC2D2A-With an emphasis on genotype-phenotype correlations, tissue specific transcripts and exploring mutation specific exon skipping therapies. Mol Genet Genomic Med 2021; 9:e1603. [PMID: 33486889 PMCID: PMC8683696 DOI: 10.1002/mgg3.1603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/18/2020] [Accepted: 01/04/2021] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Mutations in ciliary genes cause a spectrum of both overlapping and distinct clinical syndromes (ciliopathies). CEP120 and CC2D2A are paradigmatic examples for this genetic heterogeneity and pleiotropy as mutations in both cause Joubert syndrome but are also associated with skeletal ciliopathies and Meckel syndrome, respectively. The molecular basis for this phenotypical variability is not understood but basal exon skipping likely contributes to tolerance for deleterious mutations via tissue-specific preservation of the amount of expressed functional protein. METHODS We systematically reviewed and annotated genetic variants and clinical presentations reported in CEP120- and CC2D2A-associated disease and we combined in silico and ex vivo approaches to study tissue-specific transcripts and identify molecular targets for exon skipping. RESULTS We confirmed more severe clinical presentations associated with truncating CC2D2A mutations. We identified and confirmed basal exon skipping in the kidney, with possible relevance for organ-specific disease manifestations. Finally, we proposed a multimodal approach to classify exons amenable to exon skipping. By mapping reported variants, 14 truncating mutations in 7 CC2D2A exons were identified as potentially rescuable by targeted exon skipping, an approach that is already in clinical use for other inherited human diseases. CONCLUSION Genotype-phenotype correlations for CC2D2A support the deleteriousness of null alleles and CC2D2A, but not CEP120, offers potential for therapeutic exon skipping approaches.
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Affiliation(s)
- Miguel Barroso‐Gil
- Translational and Clinical Research InstituteFaculty of Medical SciencesNewcastle UniversityNewcastle Upon TyneUK
| | - Eric Olinger
- Translational and Clinical Research InstituteFaculty of Medical SciencesNewcastle UniversityNewcastle Upon TyneUK
| | - Simon A. Ramsbottom
- Translational and Clinical Research InstituteFaculty of Medical SciencesNewcastle UniversityNewcastle Upon TyneUK
| | - Elisa Molinari
- Translational and Clinical Research InstituteFaculty of Medical SciencesNewcastle UniversityNewcastle Upon TyneUK
| | - Colin G. Miles
- Translational and Clinical Research InstituteFaculty of Medical SciencesNewcastle UniversityNewcastle Upon TyneUK
| | - John A. Sayer
- Translational and Clinical Research InstituteFaculty of Medical SciencesNewcastle UniversityNewcastle Upon TyneUK
- Renal ServicesThe Newcastle upon Tyne Hospitals NHS Foundation TrustNewcastle Upon TyneUK
- NIHR Newcastle Biomedical Research CentreNewcastle UniversityNewcastle Upon TyneUK
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11
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Olinger E, Al Alawi I, Al Riyami MS, Al Salmi I, Molinari E, Faqeih EA, Al Hamed M, Barroso-Gil M, Powell L, Al-Hussaini AA, Rahim KA, Almontashiri N, Miles C, Shril S, Hildebrandt F, Wilson IJ, Sayer JA. A discarded synonymous variant in NPHP3 explains nephronophthisis and congenital hepatic fibrosis in several families. Hum Mutat 2021; 42:1221-1228. [PMID: 34212438 PMCID: PMC8434971 DOI: 10.1002/humu.24251] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 06/21/2021] [Accepted: 06/28/2021] [Indexed: 02/05/2023]
Abstract
Half of patients with a ciliopathy syndrome remain unsolved after initial analysis of whole exome sequencing (WES) data, highlighting the need for improved variant filtering and annotation. By candidate gene curation of WES data, combined with homozygosity mapping, we detected a homozygous predicted synonymous allele in NPHP3 in two children with hepatorenal fibrocystic disease from a consanguineous family. Analyses on patient-derived RNA shows activation of a cryptic mid-exon splice donor leading to frameshift. Remarkably, the same rare variant was detected in four additional families with hepatorenal disease from UK, US, and Saudi patient cohorts and in addition, another synonymous NPHP3 variant was identified in an unsolved case from the Genomics England 100,000 Genomes data set. We conclude that synonymous NPHP3 variants, not reported before and discarded by pathogenicity pipelines, solved several families with a ciliopathy syndrome. These findings prompt careful reassessment of synonymous variants, especially if they are rare and located in candidate genes.
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Affiliation(s)
- Eric Olinger
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - Intisar Al Alawi
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
- National Genetic Center, Ministry of Health, Oman
| | | | - Isa Al Salmi
- National Genetic Center, Ministry of Health, Oman
| | - Elisa Molinari
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - Eissa Ali Faqeih
- Department of Medical Genetics, Children’s Specialist Hospital, King Fahad Medical City, Riyadh Saudi Arabia
| | - Mohamed Al Hamed
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Miguel Barroso-Gil
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - Laura Powell
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - Abdulrahman A. Al-Hussaini
- Department of Medical Genetics, Children’s Specialist Hospital, King Fahad Medical City, Riyadh Saudi Arabia
| | - Khawla A. Rahim
- Department of Medical Genetics, Children’s Specialist Hospital, King Fahad Medical City, Riyadh Saudi Arabia
| | - Naif Almontashiri
- Center for Genetics and Inherited Diseases, Taibah University, Almadinah Almunwarah, Saudi Arabia
| | - Colin Miles
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - Shirlee Shril
- Division of Nephrology, Department of Pediatrics, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Friedhelm Hildebrandt
- Division of Nephrology, Department of Pediatrics, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Ian J. Wilson
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - John A. Sayer
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
- Renal Services, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE7 7DN, United Kingdom
- NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne, NE4 5PL, United Kingdom
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12
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Lord J, Baralle D. Splicing in the Diagnosis of Rare Disease: Advances and Challenges. Front Genet 2021; 12:689892. [PMID: 34276790 PMCID: PMC8280750 DOI: 10.3389/fgene.2021.689892] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/07/2021] [Indexed: 12/13/2022] Open
Abstract
Mutations which affect splicing are significant contributors to rare disease, but are frequently overlooked by diagnostic sequencing pipelines. Greater ascertainment of pathogenic splicing variants will increase diagnostic yields, ending the diagnostic odyssey for patients and families affected by rare disorders, and improving treatment and care strategies. Advances in sequencing technologies, predictive modeling, and understanding of the mechanisms of splicing in recent years pave the way for improved detection and interpretation of splice affecting variants, yet several limitations still prohibit their routine ascertainment in diagnostic testing. This review explores some of these advances in the context of clinical application and discusses challenges to be overcome before these variants are comprehensively and routinely recognized in diagnostics.
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Affiliation(s)
- Jenny Lord
- School of Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Diana Baralle
- School of Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- Wessex Clinical Genetics Service, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
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Bondue T, Arcolino FO, Veys KRP, Adebayo OC, Levtchenko E, van den Heuvel LP, Elmonem MA. Urine-Derived Epithelial Cells as Models for Genetic Kidney Diseases. Cells 2021; 10:cells10061413. [PMID: 34204173 PMCID: PMC8230018 DOI: 10.3390/cells10061413] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 05/28/2021] [Accepted: 06/02/2021] [Indexed: 12/11/2022] Open
Abstract
Epithelial cells exfoliated in human urine can include cells anywhere from the urinary tract and kidneys; however, podocytes and proximal tubular epithelial cells (PTECs) are by far the most relevant cell types for the study of genetic kidney diseases. When maintained in vitro, they have been proven extremely valuable for discovering disease mechanisms and for the development of new therapies. Furthermore, cultured patient cells can individually represent their human sources and their specific variants for personalized medicine studies, which are recently gaining much interest. In this review, we summarize the methodology for establishing human podocyte and PTEC cell lines from urine and highlight their importance as kidney disease cell models. We explore the well-established and recent techniques of cell isolation, quantification, immortalization and characterization, and we describe their current and future applications.
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Affiliation(s)
- Tjessa Bondue
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium; (T.B.); (F.O.A.); (K.R.P.V.); (O.C.A.); (E.L.); (L.P.v.d.H.)
| | - Fanny O. Arcolino
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium; (T.B.); (F.O.A.); (K.R.P.V.); (O.C.A.); (E.L.); (L.P.v.d.H.)
| | - Koenraad R. P. Veys
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium; (T.B.); (F.O.A.); (K.R.P.V.); (O.C.A.); (E.L.); (L.P.v.d.H.)
- Department of Pediatrics, Division of Pediatric Nephrology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Oyindamola C. Adebayo
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium; (T.B.); (F.O.A.); (K.R.P.V.); (O.C.A.); (E.L.); (L.P.v.d.H.)
- Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Elena Levtchenko
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium; (T.B.); (F.O.A.); (K.R.P.V.); (O.C.A.); (E.L.); (L.P.v.d.H.)
- Department of Pediatrics, Division of Pediatric Nephrology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Lambertus P. van den Heuvel
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium; (T.B.); (F.O.A.); (K.R.P.V.); (O.C.A.); (E.L.); (L.P.v.d.H.)
- Department of Pediatric Nephrology, Radboud University Medical Center, 6500 Nijmegen, The Netherlands
| | - Mohamed A. Elmonem
- Department of Clinical and Chemical Pathology, Faculty of Medicine, Cairo University, Cairo 11628, Egypt
- Correspondence:
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14
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Cell preservation methods and its application to studying rare disease. Mol Cell Probes 2021; 56:101694. [PMID: 33429040 DOI: 10.1016/j.mcp.2021.101694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/21/2020] [Accepted: 01/05/2021] [Indexed: 12/30/2022]
Abstract
The ability to preserve and transport human cells in a stable medium over long distances is critical to collaborative efforts and the advancement of knowledge in the study of human disease. This is particularly important in the study of rare diseases. Recently, advancements in the understanding of renal ciliopathies has been achieved via the use of patient urine-derived cells (UDCs). However, the traditional method of cryopreservation, although considered as the gold standard, can result in decreased sample viability of many cell types, including UDCs. Delays in transportation can have devastating effects upon the viability of samples, and may even result in complete destruction of cells following evaporation of dry ice or liquid nitrogen, leaving samples in cryoprotective agents, which are cytotoxic at room temperature. The loss of any patient sample in this manner is detrimental to research, however it is even more so when samples are from patients with a rare disease. In order to overcome the associated limitations of traditional practices, new methods of preservation and shipment, including cell encapsulation within hydrogels, and transport in specialised devices are continually being investigated. Here we summarise and compare traditional methods with emerging novel alternatives for the preservation and shipment of cells, and consider the effectiveness of such methods for use with UDCs to further enable the study and understanding of kidney diseases.
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Molinari E, Srivastava S, Dewhurst RM, Sayer JA. Use of patient derived urine renal epithelial cells to confirm pathogenicity of PKHD1 alleles. BMC Nephrol 2020; 21:435. [PMID: 33059616 PMCID: PMC7559414 DOI: 10.1186/s12882-020-02094-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 10/08/2020] [Indexed: 02/07/2023] Open
Abstract
Background PKHD1 is the main genetic cause of autosomal recessive polycystic kidney disease (ARPKD), a hereditary hepato-renal fibrocystic disorder which is the most important cause of end-stage renal disease during early childhood. ARPKD can also present in adulthood with milder phenotypes. In this study, we describe a 24-year-old woman with atypical polycystic kidney, no family history of renal disease and no obvious extra-renal manifestations who was referred for genetic investigation. Methods We used a combination of next generation sequencing, Sanger sequencing and RNA and microscopy studies performed on urine-derived renal epithelial cells (URECs) to provide a genetic diagnosis of ARPKD. Results A next generation sequencing panel of cystic ciliopathy genes allowed the identification of two heterozygous sequence changes in PKHD1 (c.6900C > T; p.(Asn2300=) and c.7964A > C; p.(His2655Pro)). The pathogenicity of the synonymous PKHD1 variant is not clear and requires RNA studies, which cannot be carried out efficiently on RNA extracted from proband blood, due to the low expression levels of PKHD1 in lymphocytes. Using URECs as a source of kidney-specific RNA, we show that PKHD1 is alternatively spliced around exon 43, both in control and proband URECs. The variant p.(Asn2300=) shifts the expression ratio in favour of a shorter, out-of-frame transcript. To further study the phenotypic consequence of these variants, we investigated the ciliary phenotype of patient URECs, which were abnormally elongated and presented multiple blebs along the axoneme. Conclusions We confirm the power of URECs as a tool for functional studies on candidate variants in inherited renal disease, especially when the expression of the gene of interest is restricted to the kidney and we describe, for the first time, ciliary abnormalities in ARPKD patient cells.
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Affiliation(s)
- Elisa Molinari
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK
| | - Shalabh Srivastava
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK
| | - Rebecca M Dewhurst
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK
| | - John A Sayer
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK. .,Renal Services, The Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE7 7DN, UK. .,NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne, UK.
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Molinari E, Sayer JA. Disease Modeling To Understand the Pathomechanisms of Human Genetic Kidney Disorders. Clin J Am Soc Nephrol 2020; 15:855-872. [PMID: 32139361 PMCID: PMC7274277 DOI: 10.2215/cjn.08890719] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The class of human genetic kidney diseases is extremely broad and heterogeneous. Accordingly, the range of associated disease phenotypes is highly variable. Many children and adults affected by inherited kidney disease will progress to ESKD at some point in life. Extensive research has been performed on various different disease models to investigate the underlying causes of genetic kidney disease and to identify disease mechanisms that are amenable to therapy. We review some of the research highlights that, by modeling inherited kidney disease, contributed to a better understanding of the underlying pathomechanisms, leading to the identification of novel genetic causes, new therapeutic targets, and to the development of new treatments. We also discuss how the implementation of more efficient genome-editing techniques and tissue-culture methods for kidney research is providing us with personalized models for a precision-medicine approach that takes into account the specificities of the patient and the underlying disease. We focus on the most common model systems used in kidney research and discuss how, according to their specific features, they can differentially contribute to biomedical research. Unfortunately, no definitive treatment exists for most inherited kidney disorders, warranting further exploitation of the existing disease models, as well as the implementation of novel, complex, human patient-specific models to deliver research breakthroughs.
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Affiliation(s)
- Elisa Molinari
- Faculty of Medical Sciences, Translational and Clinical Research Institute, International Centre for Life, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - John A. Sayer
- Faculty of Medical Sciences, Translational and Clinical Research Institute, International Centre for Life, Newcastle University, Newcastle upon Tyne, United Kingdom
- Renal Services, Newcastle Upon Tyne Hospitals National Health Service Trust, Newcastle upon Tyne, United Kingdom
- National Institute for Health Research Newcastle Biomedical Research Centre, Newcastle upon Tyne, United Kingdom
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Wheway G, Lord J, Baralle D. Splicing in the pathogenesis, diagnosis and treatment of ciliopathies. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194433. [PMID: 31698098 DOI: 10.1016/j.bbagrm.2019.194433] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/12/2019] [Accepted: 09/17/2019] [Indexed: 12/12/2022]
Abstract
Primary cilia are essential signalling organelles found on the apical surface of epithelial cells, where they coordinate chemosensation, mechanosensation and light sensation. Motile cilia play a central role in establishing fluid flow in the respiratory tract, reproductive tract, brain ventricles and ear. Genetic defects affecting the structure or function of cilia can lead to a broad range of developmental and degenerative diseases known as ciliopathies. Splicing contributes to the pathogenesis, diagnosis and treatment of ciliopathies. Tissue-specific alternative splicing contributes to the tissue-specific manifestation of ciliopathy phenotypes, for example the retinal-specific effects of some genetic defects, due to specific transcript expression in the highly specialised ciliated cells of the retina, the photoreceptor cells. Ciliopathies can arise both as a result of genetic variants in spliceosomal proteins, or as a result of variants affecting splicing of specific cilia genes. Here we discuss the opportunities and challenges in diagnosing ciliopathies using RNA sequence analysis and the potential for treating ciliopathies in a relatively mutation-neutral way by targeting splicing. This article is part of a Special Issue entitled: RNA structure and splicing regulation edited by Francisco Baralle, Ravindra Singh and Stefan Stamm.
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Affiliation(s)
- Gabrielle Wheway
- Faculty of Medicine, University of Southampton, Human Development and Health, United Kingdom of Great Britain and Northern Ireland; University Hospital Southampton NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Jenny Lord
- Faculty of Medicine, University of Southampton, Human Development and Health, United Kingdom of Great Britain and Northern Ireland; University Hospital Southampton NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Diana Baralle
- Faculty of Medicine, University of Southampton, Human Development and Health, United Kingdom of Great Britain and Northern Ireland; University Hospital Southampton NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland.
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Renal ciliopathies. Curr Opin Genet Dev 2019; 56:49-60. [DOI: 10.1016/j.gde.2019.07.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 07/09/2019] [Accepted: 07/14/2019] [Indexed: 12/19/2022]
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Browning AC, Figueiredo GS, Baylis O, Montgomery E, Beesley C, Molinari E, Figueiredo FC, Sayer JA. A case of ocular cystinosis associated with two potentially severe CTNS mutations. Ophthalmic Genet 2019; 40:157-160. [PMID: 30957593 DOI: 10.1080/13816810.2019.1592198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Ocular cystinosis is a rare autosomal recessive disorder caused by one severe and one mild mutation in the CTNS gene. It is characterised by cystine deposition within the cornea and conjunctiva however, the kidneys are not affected. We report a case of ocular cystinosis caused by two potentially severe CTNS mutations and discuss the possible mechanism of renal sparing. METHODS This is an observational case report of the proband and her unaffected relatives. All subjects underwent ophthalmic examination, whilst in the proband, In vivo laser scanning confocal microscopy was used to demonstrate cystine crystals within her corneas and conjunctiva. Genetic diagnosis was confirmed by DNA sequencing of the proband and the segregation of the mutations was established in her relatives. RT-PCR of leukocyte RNA was undertaken to determine if aberrant splicing of the CTNS gene was taking place Results: The proband was found to have cystine crystals limited to the anterior corneal stroma and the conjunctiva. Sequencing of the proband's CTNS gene found her to be a compound heterozygote for a 27bp deletion in exon8/intron 8 (c.559_561 + 24del) and a novel c.635C>T variant in exon 9 that is predicted be pathogenic and to result in the substitution of alanine with valine at amino acid position 212 (p.Ala212Val), which is within the 3rd transmembrane spanning domain of the CTNS protein. Examination of the proband's leukocyte RNA failed to demonstrate any aberrant CTNS gene splicing. CONCLUSION We present a case of ocular cystinosis caused by two potentially severe CTNS gene mutations. The lack of renal involvement may be due to localised (ocular) aberrant CTNS RNA splicing.
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Affiliation(s)
- Andrew C Browning
- a Newcastle Eye Centre , Newcastle upon Tyne Hospitals NHS Foundation Trust , Newcastle upon Tyne , UK
| | - Gustavo S Figueiredo
- a Newcastle Eye Centre , Newcastle upon Tyne Hospitals NHS Foundation Trust , Newcastle upon Tyne , UK.,b Institute of Genetic Medicine, International Centre for Life, Newcastle University , Newcastle upon Tyne , UK
| | - Oliver Baylis
- a Newcastle Eye Centre , Newcastle upon Tyne Hospitals NHS Foundation Trust , Newcastle upon Tyne , UK
| | - Emma Montgomery
- c Renal Services , Newcastle upon Tyne Hospitals NHS Foundation Trust , Newcastle upon Tyne , UK
| | - Clare Beesley
- d North East Thames Regional Genetics Service, Level 6, Barclay House , Great Ormond Street Hospital for Children NHS Foundation Trust , London , UK
| | - Elisa Molinari
- b Institute of Genetic Medicine, International Centre for Life, Newcastle University , Newcastle upon Tyne , UK
| | - Francisco C Figueiredo
- a Newcastle Eye Centre , Newcastle upon Tyne Hospitals NHS Foundation Trust , Newcastle upon Tyne , UK.,b Institute of Genetic Medicine, International Centre for Life, Newcastle University , Newcastle upon Tyne , UK
| | - John A Sayer
- b Institute of Genetic Medicine, International Centre for Life, Newcastle University , Newcastle upon Tyne , UK.,c Renal Services , Newcastle upon Tyne Hospitals NHS Foundation Trust , Newcastle upon Tyne , UK
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