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Erger F, Brüchle NO, Gembruch U, Zerres K. Prenatal ultrasound, genotype, and outcome in a large cohort of prenatally affected patients with autosomal-recessive polycystic kidney disease and other hereditary cystic kidney diseases. Arch Gynecol Obstet 2017; 295:897-906. [PMID: 28283827 DOI: 10.1007/s00404-017-4336-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 11/08/2016] [Indexed: 12/19/2022]
Abstract
PURPOSE To investigate the sonographic and clinical genotype-phenotype correlations in autosomal recessive polycystic kidney disease (ARPKD) and other cystic kidney diseases (CKD) in a large cohort of prenatally detected fetuses with hereditary CKD. METHODS We retrospectively studied the clinical and diagnostic data of 398 patients referred with prenatal ultrasound findings suggestive of CKD between 1994 and 2010. Cases with confirmed hereditary CKD (n = 130) were analyzed as to their prenatal ultrasound findings, genotype, and possible predictors of clinical outcome. RESULTS ARPKD was most common in our non-representative sample. Truncating PKHD1 mutations led to a significantly reduced neonatal prognosis, with two such mutations being invariably lethal. Sonographically visible kidney cysts occurred in only 3% of ARPKD cases. Renal abnormalities in Meckel syndrome (MKS) appeared earlier than in ADPKD (19.6 ± 3.7 vs. 29.8 ± 5.1 GW) or ARPKD (19.6 ± 3.7 vs. 30.2 ± 1.2 GW). Additional CNS malformations were not found in ARPKD, but were highly sensitive for MKS. Pulmonary hypoplasia, oligo/anhydramnios (OAH), and kidney enlargement were associated with a significantly worse neonatal prognosis. CONCLUSION Genotype, sonographic signs of OAH, enlarged kidney size, and pulmonary hypoplasia can be useful predictors of neonatal survival. We propose sonographic morphological criteria for ARPKD, ADPKD, MKS, and renal cyst and diabetes syndrome (RCAD). We further propose a clinical diagnostic algorithm for differentiating cystic kidney diseases.
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Affiliation(s)
- Florian Erger
- Institute of Human Genetics, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany.,Institute of Human Genetics, Cologne University Hospital, Cologne, Germany
| | - Nadina Ortiz Brüchle
- Institute of Human Genetics, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Ulrich Gembruch
- Department of Obstetrics and Prenatal Medicine, Bonn University Hospital, Bonn, Germany
| | - Klaus Zerres
- Institute of Human Genetics, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany.
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102
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Crawford BD, Gillies CE, Robertson CC, Kretzler M, Otto EA, Vega-Warner V, Sampson MG. Evaluating Mendelian nephrotic syndrome genes for evidence for risk alleles or oligogenicity that explain heritability. Pediatr Nephrol 2017; 32:467-476. [PMID: 27766458 PMCID: PMC5483602 DOI: 10.1007/s00467-016-3513-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 08/25/2016] [Accepted: 08/29/2016] [Indexed: 01/08/2023]
Abstract
BACKGROUND More than 30 genes can harbor rare exonic variants sufficient to cause nephrotic syndrome (NS), and the number of genes implicated in monogenic NS continues to grow. However, outside the first year of life, the majority of affected patients, particularly in ancestrally mixed populations, do not have a known monogenic form of NS. Even in those children classified with a monogenic form of NS, there is phenotypic heterogeneity. Thus, we have only discovered a fraction of the heritability of NS-the underlying genetic factors contributing to phenotypic variation. Part of the "missing heritability" for NS has been posited to be explained by patients harboring coding variants across one or more previously implicated NS genes, insufficient to cause NS in a classical Mendelian manner, but that nonetheless have a sufficient impact on protein function to cause disease. However, systematic evaluation in patients with NS for rare or low-frequency risk alleles within single genes, or in combination across genes ("oligogenicity"), has not been reported. To determine whether, compared with a reference population, patients with NS have either a significantly increased burden of protein-altering variants ("risk-alleles"), or a unique combination of them ("oligogenicity"), in a set of 21 genes implicated in Mendelian forms of NS. METHODS In 303 patients with NS enrolled in the Nephrotic Syndrome Study Network (NEPTUNE), we performed targeted amplification paired with next-generation sequencing of 21 genes implicated in monogenic NS. We created a high-quality variant call set and compared it with a variant call set of the same genes in a reference population composed of 2,535 individuals from phase 3 of the 1000 Genomes Project. We created both a "stringent" and a "relaxed" pathogenicity-filtering pipeline, applied them to both cohorts, and computed the burden of variants in the entire gene set per cohort, the burden of variants in the entire gene set per individual, the burden of variants within a single gene per cohort, and unique combinations of variants across two or more genes per cohort. RESULTS With few exceptions when using the relaxed filter, and which are likely the result of confounding by population stratification, NS patients did not have a significantly increased burden of variants in Mendelian NS genes in comparison to a reference cohort, nor was there any evidence for oligogenicity. This was true when using both the relaxed and the stringent variant pathogenicity filter. CONCLUSION In our study, there were no significant differences in the burden or particular combinations of low-frequency or rare protein-altering variants in a previously implicated Mendelian NS genes cohort between North American patients with NS and a reference population. Studies in larger independent cohorts or meta-analyses are needed to assess the generalizability of our discoveries and also address whether there is in fact small but significant enrichment of risk alleles or oligogenicity in NS cases that was undetectable with this current sample size. It is still possible that rare protein-altering variants in these genes, insufficient to cause Mendelian disease, still contribute to NS as risk alleles and/or via oligogenicity. However, we suggest that more accurate bioinformatic analyses and the incorporation of functional assays would be necessary to identify bona fide instances of this form of genetic architecture as a contributor to the heritability of NS.
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Affiliation(s)
- Brendan D Crawford
- Department of Pediatrics, University of Michigan Medical School, 3560B MSRB 2, Ann Arbor, MI, USA
| | - Christopher E Gillies
- Department of Pediatrics, University of Michigan Medical School, 3560B MSRB 2, Ann Arbor, MI, USA
| | - Catherine C Robertson
- Department of Pediatrics, University of Michigan Medical School, 3560B MSRB 2, Ann Arbor, MI, USA
| | - Matthias Kretzler
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Edgar A Otto
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Virginia Vega-Warner
- Department of Pediatrics, University of Michigan Medical School, 3560B MSRB 2, Ann Arbor, MI, USA
| | - Matthew G Sampson
- Department of Pediatrics, University of Michigan Medical School, 3560B MSRB 2, Ann Arbor, MI, USA.
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103
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De Rechter S, Breysem L, Mekahli D. Is Autosomal Dominant Polycystic Kidney Disease Becoming a Pediatric Disorder? Front Pediatr 2017; 5:272. [PMID: 29326910 PMCID: PMC5742347 DOI: 10.3389/fped.2017.00272] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 12/04/2017] [Indexed: 12/15/2022] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) affects 1 in 400 to 1,000 live births, making it the most common monogenic cause of renal failure. Although no definite cure is available yet, it is important to affect disease progression by influencing modifiable factors such as hypertension and proteinuria. Besides this symptomatic management, the only drug currently recommended in Europe for selected adult patients with rapid disease progression, is the vasopressin receptor antagonist tolvaptan. However, the question remains whether these preventive interventions should be initiated before extensive renal damage has occurred. As renal cyst formation and expansion begins early in life, frequently in utero, ADPKD should no longer be considered an adult-onset disease. Moreover, the presence of hypertension and proteinuria in affected children has been reported to correlate well with disease severity. Until now, it is controversial whether children at-risk for ADPKD should be tested for the presence of the disease, and if so, how this should be done. Herein, we review the spectrum of pediatric ADPKD and discuss the pro and contra of testing at-risk children and the challenges and unmet needs in pediatric ADPKD care.
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Affiliation(s)
- Stéphanie De Rechter
- PKD Lab, Department of Development and Regeneration, KU Leuven, Leuven, Belgium.,Department of Pediatric Nephrology, University Hospitals Leuven, Leuven, Belgium
| | - Luc Breysem
- Department of Radiology, University Hospitals Leuven, Leuven, Belgium
| | - Djalila Mekahli
- PKD Lab, Department of Development and Regeneration, KU Leuven, Leuven, Belgium.,Department of Pediatric Nephrology, University Hospitals Leuven, Leuven, Belgium
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104
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Tolvaptan treatment for severe neonatal autosomal-dominant polycystic kidney disease. Pediatr Nephrol 2017; 32:893-896. [PMID: 28194574 PMCID: PMC5368203 DOI: 10.1007/s00467-017-3584-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 12/21/2016] [Accepted: 12/21/2016] [Indexed: 12/28/2022]
Abstract
BACKGROUND Severe neonatal autosomal-dominant polycystic kidney disease (ADPKD) is rare and easily confused with recessive PKD. Managing such infants is difficult and often unsuccessful. CASE DIAGNOSIS/TREATMENT A female infant with massive renal enlargement, respiratory compromise and hyponatraemia was treated with the arginine vasopressin receptor 2 antagonist tolvaptan. This resolved hyponatraemia, and there was no further increase in renal size. CONCLUSION Tolvaptan may be a useful treatment for severe neonatal PKD.
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105
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Cordido A, Besada-Cerecedo L, García-González MA. The Genetic and Cellular Basis of Autosomal Dominant Polycystic Kidney Disease-A Primer for Clinicians. Front Pediatr 2017; 5:279. [PMID: 29326913 PMCID: PMC5741702 DOI: 10.3389/fped.2017.00279] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 12/07/2017] [Indexed: 12/14/2022] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common genetic disorders worldwide. In recent decades, the field has undergone a revolution, starting with the identification of causal ADPKD genes, including PKD1, PKD2, and the recently identified GANAB. In addition, advances defining the genetic mechanisms, protein localization and function, and the identification of numerous pathways involved in the disease process, have contributed to a better understanding of this illness. Together, this has led to a better prognosis, diagnosis, and treatment in clinical practice. In this mini review, we summarize and discuss new insights about the molecular mechanisms underlying ADPKD, including its genetics, protein function, and cellular pathways.
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Affiliation(s)
- Adrián Cordido
- Grupo de Genética y Biología del Desarrollo de las Enfermedades Renales, Laboratorio de Nefrología (n.° 11), Instituto de Investigación Sanitaria (IDIS), Complexo Hospitalario de Santiago de Compostela (CHUS), Santiago de Compostela, Spain
| | - Lara Besada-Cerecedo
- Grupo de Genética y Biología del Desarrollo de las Enfermedades Renales, Laboratorio de Nefrología (n.° 11), Instituto de Investigación Sanitaria (IDIS), Complexo Hospitalario de Santiago de Compostela (CHUS), Santiago de Compostela, Spain
| | - Miguel A García-González
- Grupo de Genética y Biología del Desarrollo de las Enfermedades Renales, Laboratorio de Nefrología (n.° 11), Instituto de Investigación Sanitaria (IDIS), Complexo Hospitalario de Santiago de Compostela (CHUS), Santiago de Compostela, Spain
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106
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Sweeney WE, Avner ED. Emerging Therapies for Childhood Polycystic Kidney Disease. Front Pediatr 2017; 5:77. [PMID: 28473970 PMCID: PMC5395658 DOI: 10.3389/fped.2017.00077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/30/2017] [Indexed: 12/28/2022] Open
Abstract
Cystic kidney diseases comprise a varied collection of hereditary disorders, where renal cysts comprise a major element of their pleiotropic phenotype. In pediatric patients, the term polycystic kidney disease (PKD) commonly refers to two specific hereditary diseases, autosomal recessive polycystic kidney disease (ARPKD) and autosomal dominant polycystic kidney disease (ADPKD). Remarkable progress has been made in understanding the complex molecular and cellular mechanisms of renal cyst formation in ARPKD and ADPKD. One of the most important discoveries is that both the genes and proteins products of ARPKD and ADPKD interact in a complex network of genetic and functional interactions. These interactions and the shared phenotypic abnormalities of ARPKD and ADPKD, the "cystic phenotypes" suggest that many of the therapies developed and tested for ADPKD may be effective in ARPKD as well. Successful therapeutic interventions for childhood PKD will, therefore, be guided by knowledge of these molecular interactions, as well as a number of clinical parameters, such as the stage of the disease and the rate of disease progression.
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Affiliation(s)
- William E Sweeney
- Department of Pediatrics, Medical College of Wisconsin, Children's Research Institute, Children's Hospital Health System of Wisconsin, Milwaukee, WI, USA
| | - Ellis D Avner
- Department of Pediatrics, Medical College of Wisconsin, Children's Research Institute, Children's Hospital Health System of Wisconsin, Milwaukee, WI, USA
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107
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Harris T. Is It Ethical to Test Apparently "Healthy" Children for Autosomal Dominant Polycystic Kidney Disease and Risk Medicalizing Thousands? Front Pediatr 2017; 5:291. [PMID: 29404310 PMCID: PMC5780433 DOI: 10.3389/fped.2017.00291] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 12/20/2017] [Indexed: 12/18/2022] Open
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108
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Bergmann C. Genetics of Autosomal Recessive Polycystic Kidney Disease and Its Differential Diagnoses. Front Pediatr 2017; 5:221. [PMID: 29479522 PMCID: PMC5811498 DOI: 10.3389/fped.2017.00221] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 10/02/2017] [Indexed: 01/09/2023] Open
Abstract
Autosomal recessive polycystic kidney disease (ARPKD) is a hepatorenal fibrocystic disorder that is characterized by enlarged kidneys with progressive loss of renal function and biliary duct dilatation and congenital hepatic fibrosis that leads to portal hypertension in some patients. Mutations in the PKHD1 gene are the primary cause of ARPKD; however, the disease is genetically not as homogeneous as long thought and mutations in several other cystogenes can phenocopy ARPKD. The family history usually is negative, both for recessive, but also often for dominant disease genes due to de novo arisen mutations or recessive inheritance of variants in genes that usually follow dominant patterns such as the main ADPKD genes PKD1 and PKD2. Considerable progress has been made in the understanding of polycystic kidney disease (PKD). A reduced dosage of disease proteins leads to the disruption of signaling pathways underlying key mechanisms involved in cellular homeostasis, which may help to explain the accelerated and severe clinical progression of disease course in some PKD patients. A comprehensive knowledge of disease-causing genes is essential for counseling and to avoid genetic misdiagnosis, which is particularly important in the prenatal setting (e.g., preimplantation genetic diagnosis/PGD). For ARPKD, there is a strong demand for early and reliable prenatal diagnosis, which is only feasible by molecular genetic analysis. A clear genetic diagnosis is helpful for many families and improves the clinical management of patients. Unnecessary and invasive measures can be avoided and renal and extrarenal comorbidities early be detected in the clinical course. The increasing number of genes that have to be considered benefit from the advances of next-generation sequencing (NGS) which allows simultaneous analysis of a large group of genes in a single test at relatively low cost and has become the mainstay for genetic diagnosis. The broad phenotypic and genetic heterogeneity of cystic and polycystic kidney diseases make NGS a particularly powerful approach for these indications. Interpretation of genetic data becomes the challenge and requires deep clinical understanding.
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Affiliation(s)
- Carsten Bergmann
- Center for Human Genetics, Bioscientia, Ingelheim, Germany.,Department of Medicine, University Hospital Freiburg, Freiburg, Germany
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109
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Leonhard WN, Happe H, Peters DJM. Variable Cyst Development in Autosomal Dominant Polycystic Kidney Disease: The Biologic Context. J Am Soc Nephrol 2016; 27:3530-3538. [PMID: 27493259 PMCID: PMC5118495 DOI: 10.1681/asn.2016040425] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Patients with autosomal dominant polycystic kidney disease (ADPKD) typically carry a mutation in either the PKD1 or PKD2 gene, which leads to massive cyst formation in both kidneys. However, the large intrafamilial variation in the progression rate of ADPKD suggests involvement of additional factors other than the type of mutation. The identification of these factors will increase our understanding of ADPKD and could ultimately help in the development of a clinically relevant therapy. Our review addresses the mechanisms by which various biologic processes influence cyst formation and cyst growth, thereby explaining an important part of the inter- and intrafamilial variability in ADPKD. Numerous studies from many laboratories provide compelling evidence for the influence on cyst formation by spatiotemporal gene inactivation, the genetic context, the metabolic status, the presence of existing cysts, and whether the kidneys were challenged by renal injury. Collectively, a solid basis is provided for the concept that the probability of cyst formation is determined by functional PKD protein levels and the biologic context. We model these findings in a graphic representation called the cystic probability landscape, providing a robust conceptual understanding of why cells sometimes do or do not form cysts.
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Affiliation(s)
- Wouter N Leonhard
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Hester Happe
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Dorien J M Peters
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
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110
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Tchan M, Savige J, Patel C, Mallett A, Tong A, Tunnicliffe DJ, Rangan GK. KHA-CARI Autosomal Dominant Polycystic Kidney Disease Guideline: Genetic Testing for Diagnosis. Semin Nephrol 2016; 35:545-549.e2. [PMID: 26718157 DOI: 10.1016/j.semnephrol.2015.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Michel Tchan
- Department of Genetic Medicine, Westmead Hospital, Western Sydney Local Health District, Sydney, Australia; Sydney Medical School, The University of Sydney, Sydney, Australia.
| | - Judy Savige
- The University of Melbourne, Department of Medicine, Melbourne Health and Northern Health, Melbourne, Australia; Department of Nephrology, The Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Chirag Patel
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
| | - Andrew Mallett
- Kidney Health Service and Conjoint Kidney Research Laboratory, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia; Centre for Kidney Disease Research, Centre for Chronic Disease and CKD, School of Medicine and Centre for Rare Diseases Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Allison Tong
- Sydney School of Public Health, University of Sydney, NSW, Australia; Centre for Kidney Research, The Children's Hospital at Westmead, Westmead, NSW, Australia
| | - David J Tunnicliffe
- Sydney School of Public Health, University of Sydney, NSW, Australia; KHA-CARI Guidelines, Centre for Kidney Research, The Children's Hospital at Westmead, Westmead, Sydney, Australia
| | - Gopala K Rangan
- Department of Renal Medicine, Westmead Hospital, Western Sydney Local Health District, Sydney, Australia; Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Westmead, Sydney, Australia
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111
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Rangan GK, Lopez-Vargas P, Nankivell BJ, Tchan M, Tong A, Tunnicliffe DJ, Savige J. Autosomal Dominant Polycystic Kidney Disease: A Path Forward. Semin Nephrol 2016; 35:524-37. [PMID: 26718155 DOI: 10.1016/j.semnephrol.2015.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the commonest inherited cause of renal failure in adults, and is due to loss-of-function mutations in either the PKD1 or PKD2 genes, which encode polycystin-1 and polycystin-2, respectively. These proteins have an essential role in maintaining the geometric structure of the distal collecting duct in the kidney in adult life, and their dysfunction predisposes to renal cyst formation. The typical renal phenotype of ADPKD is the insidious development of hundreds of renal cysts, which form in childhood and grow progressively through life, causing end-stage kidney failure in the fifth decade in about half affected by the mutation. Over the past 2 decades, major advances in genetics and disease pathogenesis have led to well-conducted randomized controlled trials, and observational studies that have resulted in an accumulation of evidence-based data, and raise hope that the lifetime risk of kidney failure due to ADPKD will be progressively curtailed during this century. This review will provide a contemporary summary of the current state of the field in disease pathogenesis and therapeutics, and also briefly highlights the importance of clinical practice guidelines, patient perspectives, patient-reported outcomes, uniform trial reporting, and health-economics in ADPKD.
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Affiliation(s)
- Gopala K Rangan
- Department of Renal Medicine, Westmead Hospital, Western Sydney Local Health District, Westmead, Sydney, Australia; Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Westmead, Sydney, Australia.
| | - Pamela Lopez-Vargas
- Sydney School of Public Health, The University of Sydney, Sydney, Australia; Centre for Kidney Research, The Children's Hospital at Westmead, Sydney, Australia
| | - Brian J Nankivell
- Department of Renal Medicine, Westmead Hospital, Western Sydney Local Health District, Westmead, Sydney, Australia; Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Westmead, Sydney, Australia
| | - Michel Tchan
- Department of Genetic Medicine, Westmead Hospital, Western Sydney Local Health District, Sydney, Australia
| | - Allison Tong
- Sydney School of Public Health, The University of Sydney, Sydney, Australia; Centre for Kidney Research, The Children's Hospital at Westmead, Sydney, Australia
| | - David J Tunnicliffe
- Sydney School of Public Health, The University of Sydney, Sydney, Australia; Centre for Kidney Research, The Children's Hospital at Westmead, Sydney, Australia
| | - Judy Savige
- The University of Melbourne, Department of Medicine, Melbourne Health and Northern Health, Melbourne, Australia; Department of Nephrology, The Royal Melbourne Hospital, Parkville, Victoria, Australia
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112
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Chen W, Perritt AF, Morissette R, Dreiling JL, Bohn MF, Mallappa A, Xu Z, Quezado M, Merke DP. Ehlers-Danlos Syndrome Caused by Biallelic TNXB Variants in Patients with Congenital Adrenal Hyperplasia. Hum Mutat 2016; 37:893-7. [PMID: 27297501 DOI: 10.1002/humu.23028] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 06/01/2016] [Indexed: 01/13/2023]
Abstract
Some variants that cause autosomal-recessive congenital adrenal hyperplasia (CAH) also cause hypermobility type Ehlers-Danlos syndrome (EDS) due to the monoallelic presence of a chimera disrupting two flanking genes: CYP21A2, encoding 21-hydroxylase, necessary for cortisol and aldosterone biosynthesis, and TNXB, encoding tenascin-X, an extracellular matrix protein. Two types of CAH tenascin-X (CAH-X) chimeras have been described with a total deletion of CYP21A2 and characteristic TNXB variants. CAH-X CH-1 has a TNXB exon 35 120-bp deletion resulting in haploinsufficiency, and CAH-X CH-2 has a TNXB exon 40 c.12174C>G (p.Cys4058Trp) variant resulting in a dominant-negative effect. We present here three patients with biallelic CAH-X and identify a novel dominant-negative chimera termed CAH-X CH-3. Compared with monoallelic CAH-X, biallelic CAH-X results in a more severe phenotype with skin features characteristic of classical EDS. We present evidence for disrupted tenascin-X function and computational data linking the type of TNXB variant to disease severity.
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Affiliation(s)
- Wuyan Chen
- PreventionGenetics, Marshfield, Wisconsin
| | - Ashley F Perritt
- National Institutes of Health Clinical Center, Bethesda, Maryland
| | | | | | - Markus-Frederik Bohn
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California
| | - Ashwini Mallappa
- National Institutes of Health Clinical Center, Bethesda, Maryland
| | - Zhi Xu
- National Institutes of Health, , National Institute on Aging, Baltimore, Maryland
| | - Martha Quezado
- Laboratory of Pathology, National Cancer Institute, Bethesda, Maryland
| | - Deborah P Merke
- National Institutes of Health Clinical Center, Bethesda, Maryland.,The Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland
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113
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The expanding phenotypic spectra of kidney diseases: insights from genetic studies. Nat Rev Nephrol 2016; 12:472-83. [PMID: 27374918 DOI: 10.1038/nrneph.2016.87] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Next-generation sequencing (NGS) has led to the identification of previously unrecognized phenotypes associated with classic kidney disease genes. In addition to improving diagnostics for genetically heterogeneous diseases and enabling a faster rate of gene discovery, NGS has enabled an expansion and redefinition of nephrogenetic disease categories. Findings from these studies raise the question of whether disease diagnoses should be made on clinical grounds, on genetic evidence or a combination thereof. Here, we discuss the major kidney disease-associated genes and gene categories for which NGS has expanded the phenotypic spectrum. For example, COL4A3-5 genes, which are classically associated with Alport syndrome, are now understood to also be involved in the aetiology of focal segmental glomerulosclerosis. DGKE, which is associated with nephrotic syndrome, is also mutated in patients with atypical haemolytic uraemic syndrome. We examine how a shared genetic background between diverse clinical phenotypes can provide insight into the function of genes and novel links with essential pathophysiological mechanisms. In addition, we consider genetic and epigenetic factors that contribute to the observed phenotypic heterogeneity of kidney diseases and discuss the challenges in the interpretation of genetic data. Finally, we discuss the implications of the expanding phenotypic spectra associated with kidney disease genes for clinical practice, genetic counselling and personalized care, and present our recommendations for the use of NGS-based tests in routine nephrology practice.
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114
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Hwang YH, Conklin J, Chan W, Roslin NM, Liu J, He N, Wang K, Sundsbak JL, Heyer CM, Haider M, Paterson AD, Harris PC, Pei Y. Refining Genotype-Phenotype Correlation in Autosomal Dominant Polycystic Kidney Disease. J Am Soc Nephrol 2016; 27:1861-8. [PMID: 26453610 PMCID: PMC4884120 DOI: 10.1681/asn.2015060648] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Accepted: 09/10/2015] [Indexed: 11/03/2022] Open
Abstract
Renal disease variability in autosomal dominant polycystic kidney disease (ADPKD) is strongly influenced by the gene locus (PKD1 versus PKD2). Recent studies identified nontruncating PKD1 mutations in approximately 30% of patients who underwent comprehensive mutation screening, but the clinical significance of these mutations is not well defined. We examined the genotype-renal function correlation in a prospective cohort of 220 unrelated ADPKD families ascertained through probands with serum creatinine ≤1.4 mg/dl at recruitment. We screened these families for PKD1 and PKD2 mutations and reviewed the clinical outcomes of the probands and affected family members. Height-adjusted total kidney volume (htTKV) was obtained in 161 affected subjects. Multivariate Cox proportional hazard modeling for renal and patient survival was performed in 707 affected probands and family members. Overall, we identified pathogenic mutations in 84.5% of our families, in which the prevalence of PKD1 truncating, PKD1 in-frame insertion/deletion, PKD1 nontruncating, and PKD2 mutations was 38.3%, 4.3%, 27.1%, and 30.3%, respectively. Compared with patients with PKD1 truncating mutations, patients with PKD1 in-frame insertion/deletion, PKD1 nontruncating, or PKD2 mutations have smaller htTKV and reduced risks (hazard ratio [95% confidence interval]) of ESRD (0.35 [0.14 to 0.91], 0.10 [0.05 to 0.18], and 0.03 [0.01 to 0.05], respectively) and death (0.31 [0.11 to 0.87], 0.20 [0.11 to 0.38], and 0.18 [0.11 to 0.31], respectively). Refined genotype-renal disease correlation coupled with targeted next generation sequencing of PKD1 and PKD2 may provide useful clinical prognostication for ADPKD.
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Affiliation(s)
- Young-Hwan Hwang
- Department of Medicine, Eulji General Hospital, Seoul, South Korea; Division of Nephrology and
| | - John Conklin
- Department of Medical Imaging, University Health Network and University of Toronto, Toronto, Ontario, Canada
| | | | - Nicole M Roslin
- Program in Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada; and
| | | | | | | | - Jamie L Sundsbak
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Christina M Heyer
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Masoom Haider
- Department of Medical Imaging, University Health Network and University of Toronto, Toronto, Ontario, Canada
| | - Andrew D Paterson
- Program in Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada; and
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
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115
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Saigusa T, Bell PD. Molecular pathways and therapies in autosomal-dominant polycystic kidney disease. Physiology (Bethesda) 2016; 30:195-207. [PMID: 25933820 DOI: 10.1152/physiol.00032.2014] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Autosomal-dominant polycystic kidney disease (ADPKD) is the most prevalent inherited renal disease, characterized by multiple cysts that can eventually lead to kidney failure. Studies investigating the role of primary cilia and polycystins have significantly advanced our understanding of the pathogenesis of PKD. This review will present clinical and basic aspects of ADPKD, review current concepts of PKD pathogenesis, evaluate potential therapeutic targets, and highlight challenges for future clinical studies.
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Affiliation(s)
- Takamitsu Saigusa
- Department of Medicine, Division of Nephrology, Medical University of South Carolina, Charleston, South Carolina; and Ralph Johnson VA Medical Center, Charleston, South Carolina
| | - P Darwin Bell
- Department of Medicine, Division of Nephrology, Medical University of South Carolina, Charleston, South Carolina; and Ralph Johnson VA Medical Center, Charleston, South Carolina
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116
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Contribution of theTTC21Bgene to glomerular and cystic kidney diseases. Nephrol Dial Transplant 2016; 32:151-156. [DOI: 10.1093/ndt/gfv453] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 12/18/2015] [Indexed: 12/23/2022] Open
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117
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Heyer CM, Sundsbak JL, Abebe KZ, Chapman AB, Torres VE, Grantham JJ, Bae KT, Schrier RW, Perrone RD, Braun WE, Steinman TI, Mrug M, Yu ASL, Brosnahan G, Hopp K, Irazabal MV, Bennett WM, Flessner MF, Moore CG, Landsittel D, Harris PC. Predicted Mutation Strength of Nontruncating PKD1 Mutations Aids Genotype-Phenotype Correlations in Autosomal Dominant Polycystic Kidney Disease. J Am Soc Nephrol 2016; 27:2872-84. [PMID: 26823553 DOI: 10.1681/asn.2015050583] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 12/09/2015] [Indexed: 01/12/2023] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) often results in ESRD but with a highly variable course. Mutations to PKD1 or PKD2 cause ADPKD; both loci have high levels of allelic heterogeneity. We evaluated genotype-phenotype correlations in 1119 patients (945 families) from the HALT Progression of PKD Study and the Consortium of Radiologic Imaging Study of PKD Study. The population was defined as: 77.7% PKD1, 14.7% PKD2, and 7.6% with no mutation detected (NMD). Phenotypic end points were sex, eGFR, height-adjusted total kidney volume (htTKV), and liver cyst volume. Analysis of the eGFR and htTKV measures showed that the PKD1 group had more severe disease than the PKD2 group, whereas the NMD group had a PKD2-like phenotype. In both the PKD1 and PKD2 populations, men had more severe renal disease, but women had larger liver cyst volumes. Compared with nontruncating PKD1 mutations, truncating PKD1 mutations associated with lower eGFR, but the mutation groups were not differentiated by htTKV. PKD1 nontruncating mutations were evaluated for conservation and chemical change and subdivided into strong (mutation strength group 2 [MSG2]) and weak (MSG3) mutation groups. Analysis of eGFR and htTKV measures showed that patients with MSG3 but not MSG2 mutations had significantly milder disease than patients with truncating cases (MSG1), an association especially evident in extreme decile populations. Overall, we have quantified the contribution of genic and PKD1 allelic effects and sex to the ADPKD phenotype. Intrafamilial correlation analysis showed that other factors shared by families influence htTKV, with these additional genetic/environmental factors significantly affecting the ADPKD phenotype.
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Affiliation(s)
- Christina M Heyer
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Jamie L Sundsbak
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | | | | | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Jared J Grantham
- Kidney Institute, Kansas University Medical Center, Kansas City, Kansas
| | - Kyongtae T Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Robert W Schrier
- Division of Nephrology, University of Colorado Health Sciences Center, Denver, Colorado
| | - Ronald D Perrone
- Division of Nephrology, Tufts Medical Center, Boston, Massachusetts
| | - William E Braun
- Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio
| | - Theodore I Steinman
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Michal Mrug
- Division of Nephrology, University of Alabama, Birmingham, Alabama
| | - Alan S L Yu
- Kidney Institute, Kansas University Medical Center, Kansas City, Kansas
| | - Godela Brosnahan
- Division of Nephrology, University of Colorado Health Sciences Center, Denver, Colorado
| | - Katharina Hopp
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Maria V Irazabal
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - William M Bennett
- Legacy Transplant Services, Legacy Good Samaritan Hospital, Portland, Oregon
| | - Michael F Flessner
- National Institute of Diabetes, Digestive and Kidney Diseases, Bethesda, Maryland; and
| | - Charity G Moore
- Dickson Advanced Analytics, Carolinas HealthCare System, Charlotte, North Carolina
| | | | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota;
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118
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Weber S, Büscher AK, Hagmann H, Liebau MC, Heberle C, Ludwig M, Rath S, Alberer M, Beissert A, Zenker M, Hoyer PF, Konrad M, Klein HG, Hoefele J. Dealing with the incidental finding of secondary variants by the example of SRNS patients undergoing targeted next-generation sequencing. Pediatr Nephrol 2016; 31:73-81. [PMID: 26248470 DOI: 10.1007/s00467-015-3167-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 06/29/2015] [Accepted: 06/30/2015] [Indexed: 01/15/2023]
Abstract
BACKGROUND Steroid-resistant nephrotic syndrome (SRNS) is a severe cause of progressive renal disease. Genetic forms of SRNS can present with autosomal recessive or autosomal dominant inheritance. Recent studies have identified mutations in multiple podocyte genes responsible for SRNS. Improved sequencing methods (next-generation sequencing, NGS) now promise rapid mutational testing of SRNS genes. METHODS In the present study, a simultaneous screening of ten SRNS genes in 37 SRNS patients was performed by NGS. RESULTS In 38 % of the patients, causative mutations in one SRNS gene were found. In 22 % of the patients, in addition to these mutations, a secondary variant in a different gene was identified. CONCLUSIONS This high incidence of accumulating sequence variants was unexpected but, although they might have modifier effects, the pathogenic potential of these additional sequence variants seems unclear so far. The example of molecular diagnostics by NGS in SRNS patients shows that these new sequencing technologies might provide further insight into molecular pathogenicity in genetic disorders but will also generate results, which will be difficult to interpret and complicate genetic counseling. Although NGS promises more frequent identification of disease-causing mutations, the identification of causative mutations, the interpretation of incidental findings and possible pitfalls might pose problems, which hopefully will decrease by further experience and elucidation of molecular interactions.
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Affiliation(s)
- Stefanie Weber
- Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | - Anja K Büscher
- Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | - Henning Hagmann
- Renal Division, Department II of Internal Medicine and Center for Molecular Medicine, University of Cologne, Cologne, Germany
| | - Max C Liebau
- Renal Division, Department II of Internal Medicine and Center for Molecular Medicine, University of Cologne, Cologne, Germany
- Department of Pediatrics, University Hospital of Cologne, Cologne, Germany
| | - Christian Heberle
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany
| | - Michael Ludwig
- Department of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Sabine Rath
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany
| | - Martin Alberer
- Department of Infectious Diseases and Tropical Medicine, Ludwig-Maximilians University, Munich, Germany
| | - Antje Beissert
- Pediatric Nephrology, University Children's Hospital, Würzburg, Germany
| | - Martin Zenker
- Institute of Human Genetics, University Hospital, Magdeburg, Germany
| | - Peter F Hoyer
- Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | | | - Hanns-Georg Klein
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany
| | - Julia Hoefele
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany.
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119
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Park HC, Ahn C. Diagnostic Evaluation as a Biomarker in Patients with ADPKD. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 933:85-103. [PMID: 27730437 DOI: 10.1007/978-981-10-2041-4_8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Recently, newer treatments have been introduced for autosomal dominant polycystic kidney disease (ADPKD) patients. Since cysts grow and renal function declines over a long period of time, the evaluation of treatment effects in ADPKD has been very difficult. Therefore, there has been a great interest to find out the "better" surrogate marker or biomarker which reflects disease progression. Biomarkers in ADPKD should have three clinical implications: (1) They should reflect disease severity, (2) they should distinguish patients with poor versus good prognosis to select those who will benefit better from the treatment, and (3) they should be easy to evaluate short-term outcome after treatment, which will demonstrate hard outcome. Herein, we will discuss currently available surrogate biomarkers including the volume of total kidney and urinary molecular markers.
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Affiliation(s)
- Hayne Cho Park
- Division of Nephrology, Department of Internal Medicine, The Armed Forces Capital Hospital, Seongnam-si, Gyeonggi-do, South Korea.
| | - Curie Ahn
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea
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120
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Obeidova L, Seeman T, Elisakova V, Reiterova J, Puchmajerova A, Stekrova J. Molecular genetic analysis of PKHD1 by next-generation sequencing in Czech families with autosomal recessive polycystic kidney disease. BMC MEDICAL GENETICS 2015; 16:116. [PMID: 26695994 PMCID: PMC4689053 DOI: 10.1186/s12881-015-0261-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 12/11/2015] [Indexed: 12/18/2022]
Abstract
Background Autosomal recessive polycystic kidney disease (ARPKD) is an early-onset form of polycystic kidney disease that often leads to devastating outcomes for patients. ARPKD is caused by mutations in the PKHD1 gene, an extensive gene that encodes for the ciliary protein fibrocystin/polyductin. Next-generation sequencing is presently the best option for molecular diagnosis of ARPKD. Our aim was to set up the first study of ARPKD patients from the Czech Republic, to determine the composition of their mutations and genotype-phenotype correlations, along with establishment of next-generation sequencing of the PKHD1 gene that could be used for the diagnosis of ARPKD patients. Methods Mutational analysis of the PKHD1 gene was performed in 24 families using the amplicon-based next-generation sequencing (NGS) technique. In patients without 2 causal mutations identified by NGS, subsequent MLPA analysis of the PKHD1 gene was carried out. Results Two underlying mutations were detected in 54 % of families (n = 13), one mutation in 13 % of families (n = 3), and in 33 % of families (n = 8) no mutation could be detected. Overall, seventeen different mutations (5 novel) were detected, including deletion of one exon. The detection rate in our study reached 60 % in the entire cohort of patients; but 90 % in the group of patients who fulfilled all clinical criteria of ARPKD, and 42 % in the group of patients with unknown kidney pathology. The most frequent mutation was T36M, accounting for nearly 21 % of all identified mutations. Conclusions Next-generation sequencing of the PKHD1 gene is a very useful method of molecular diagnosis in patients with a full clinical picture of ARPKD, and it has a high detection rate. Furthermore, its relatively low costs and rapidity allow the molecular genetic analysis of patients without the full clinical criteria of ARPKD, who might also have mutations in the PKHD1 gene.
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Affiliation(s)
- Lena Obeidova
- Institute of Biology and Medical Genetics of the First Faculty of Medicine, General University Hospital in Prague, Prague, Czech.
| | - Tomas Seeman
- Department of Paediatrics, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague, Czech.
| | - Veronika Elisakova
- Institute of Biology and Medical Genetics of the First Faculty of Medicine, General University Hospital in Prague, Prague, Czech.
| | - Jana Reiterova
- Department of Nephrology, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Prague, Czech.
| | - Alena Puchmajerova
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague, Czech.
| | - Jitka Stekrova
- Institute of Biology and Medical Genetics of the First Faculty of Medicine, General University Hospital in Prague, Prague, Czech.
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121
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Xu Y, Streets AJ, Hounslow AM, Tran U, Jean-Alphonse F, Needham AJ, Vilardaga JP, Wessely O, Williamson MP, Ong ACM. The Polycystin-1, Lipoxygenase, and α-Toxin Domain Regulates Polycystin-1 Trafficking. J Am Soc Nephrol 2015; 27:1159-73. [PMID: 26311459 DOI: 10.1681/asn.2014111074] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 07/21/2015] [Indexed: 12/24/2022] Open
Abstract
Mutations in polycystin-1 (PC1) give rise to autosomal dominant polycystic kidney disease, an important and common cause of kidney failure. Despite its medical importance, the function of PC1 remains poorly understood. Here, we investigated the role of the intracellular polycystin-1, lipoxygenase, and α-toxin (PLAT) signature domain of PC1 using nuclear magnetic resonance, biochemical, cellular, and in vivo functional approaches. We found that the PLAT domain targets PC1 to the plasma membrane in polarized epithelial cells by a mechanism involving the selective binding of the PLAT domain to phosphatidylserine and L-α-phosphatidylinositol-4-phosphate (PI4P) enriched in the plasma membrane. This process is regulated by protein kinase A phosphorylation of the PLAT domain, which reduces PI4P binding and recruits β-arrestins and the clathrin adaptor AP2 to trigger PC1 internalization. Our results reveal a physiological role for the PC1-PLAT domain in renal epithelial cells and suggest that phosphorylation-dependent internalization of PC1 is closely linked to its function in renal development and homeostasis.
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Affiliation(s)
- Yaoxian Xu
- Kidney Genetics Group, Academic Nephrology Unit, University of Sheffield Medical School, Sheffield, United Kingdom; Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Andrew J Streets
- Kidney Genetics Group, Academic Nephrology Unit, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Andrea M Hounslow
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Uyen Tran
- Department of Cellular and Molecular Medicine, Cleveland Clinic Foundation, Cleveland, Ohio; and
| | - Frederic Jean-Alphonse
- Laboratory of GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Andrew J Needham
- Kidney Genetics Group, Academic Nephrology Unit, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Jean-Pierre Vilardaga
- Laboratory of GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Oliver Wessely
- Department of Cellular and Molecular Medicine, Cleveland Clinic Foundation, Cleveland, Ohio; and
| | - Michael P Williamson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Albert C M Ong
- Kidney Genetics Group, Academic Nephrology Unit, University of Sheffield Medical School, Sheffield, United Kingdom;
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122
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Abstract
It is 20 years since the identification of PKD1, the major gene mutated in autosomal dominant polycystic kidney disease (ADPKD), followed closely by the cloning of PKD2. These major breakthroughs have led in turn to a period of intense investigation into the function of the two proteins encoded, polycystin-1 and polycystin-2, and how defects in either protein lead to cyst formation and nonrenal phenotypes. In this review, we summarize the major findings in this area and present a current model of how the polycystin proteins function in health and disease.
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123
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Cornec-Le Gall E, Audrézet MP, Le Meur Y, Chen JM, Férec C. Genetics and pathogenesis of autosomal dominant polycystic kidney disease: 20 years on. Hum Mutat 2015; 35:1393-406. [PMID: 25263802 DOI: 10.1002/humu.22708] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 09/22/2014] [Indexed: 12/27/2022]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD), the most common inherited kidney disorder, is characterized by the progressive development and expansion of bilateral fluid-filled cysts derived from the renal tubule epithelial cells. Although typically leading to end-stage renal disease in late middle age, ADPKD represents a continuum, from neonates with hugely enlarged cystic kidneys to cases with adequate kidney function into old age. Since the identification of the first causative gene (i.e., PKD1, encoding polycystin 1) 20 years ago, genetic studies have uncovered a large part of the key factors that underlie the phenotype variability. Here, we provide a comprehensive review of these significant advances as well as those related to disease pathogenesis models, including mutation analysis of PKD1 and PKD2 (encoding polycystin 2), current mutation detection rate, allelic heterogeneity, genotype and phenotype relationships (in terms of three different inheritance patterns: classical autosomal dominant inheritance, complex inheritance, and somatic and germline mosaicism), modifier genes, the role of second somatic mutation hit in renal cystogenesis, and findings from mouse models of polycystic kidney disease. Based upon a combined consideration of the current knowledge, we attempted to propose a unifying framework for explaining the phenotype variability in ADPKD.
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Affiliation(s)
- Emilie Cornec-Le Gall
- Institut National de la Santé et de la Recherche Médicale (INSERM), Brest, France; Faculté de Médecine et des Sciences de la Santé, Université de Bretagne Occidentale, Brest, France; Service de Néphrologie, Hémodialyse et Transplantation Rénale, Centre Hospitalier Régional Universitaire, Hôpital de la Cavale Blanche, Brest, France
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124
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Audrézet MP, Corbiere C, Lebbah S, Morinière V, Broux F, Louillet F, Fischbach M, Zaloszyc A, Cloarec S, Merieau E, Baudouin V, Deschênes G, Roussey G, Maestri S, Visconti C, Boyer O, Abel C, Lahoche A, Randrianaivo H, Bessenay L, Mekahli D, Ouertani I, Decramer S, Ryckenwaert A, Cornec-Le Gall E, Salomon R, Ferec C, Heidet L. Comprehensive PKD1 and PKD2 Mutation Analysis in Prenatal Autosomal Dominant Polycystic Kidney Disease. J Am Soc Nephrol 2015; 27:722-9. [PMID: 26139440 DOI: 10.1681/asn.2014101051] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 05/12/2015] [Indexed: 11/03/2022] Open
Abstract
Prenatal forms of autosomal dominant polycystic kidney disease (ADPKD) are rare but can be recurrent in some families, suggesting a common genetic modifying background. Few patients have been reported carrying, in addition to the familial mutation, variation(s) in polycystic kidney disease 1 (PKD1) or HNF1 homeobox B (HNF1B), inherited from the unaffected parent, or biallelic polycystic kidney and hepatic disease 1 (PKHD1) mutations. To assess the frequency of additional variations in PKD1, PKD2, HNF1B, and PKHD1 associated with the familial PKD mutation in early ADPKD, these four genes were screened in 42 patients with early ADPKD in 41 families. Two patients were associated with de novo PKD1 mutations. Forty patients occurred in 39 families with known ADPKD and were associated with PKD1 mutation in 36 families and with PKD2 mutation in two families (no mutation identified in one family). Additional PKD variation(s) (inherited from the unaffected parent when tested) were identified in 15 of 42 patients (37.2%), whereas these variations were observed in 25 of 174 (14.4%, P=0.001) patients with adult ADPKD. No HNF1B variations or PKHD1 biallelic mutations were identified. These results suggest that, at least in some patients, the severity of the cystic disease is inversely correlated with the level of polycystin 1 function.
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Affiliation(s)
- Marie-Pierre Audrézet
- Laboratory of Molecular Genetics and Histocompatibility, University Hospital of Brest, Institut National de la Santé et de la Recherche Médicale, U1078, Brest, France
| | - Christine Corbiere
- Assistance Publique des Hôpitaux de Paris, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Department of Pediatric Nephrology, University Hospital Necker-Enfants Malades Paris, France
| | - Said Lebbah
- Assistance Publique des Hôpitaux de Paris, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Department of Pediatric Nephrology, University Hospital Necker-Enfants Malades Paris, France
| | - Vincent Morinière
- Assistance Publique des Hôpitaux de Paris, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Department of Pediatric Nephrology, University Hospital Necker-Enfants Malades Paris, France
| | - Françoise Broux
- Department of Medical Pediatrics, Pediatric Nephrology and Hemodialysis Unit, University Hospital Charles Nicolle, Rouen, France
| | - Ferielle Louillet
- Department of Medical Pediatrics, Pediatric Nephrology and Hemodialysis Unit, University Hospital Charles Nicolle, Rouen, France
| | - Michel Fischbach
- Department of Pediatrics 1, University Hospital of Strasbourg Strasbourg, France
| | - Ariane Zaloszyc
- Department of Pediatrics 1, University Hospital of Strasbourg Strasbourg, France
| | - Sylvie Cloarec
- Department of Pediatric Nephrology and Hemodialysis, Clocheville Hospital, University Hospital of Tours, Tours, France
| | - Elodie Merieau
- Department of Pediatric Nephrology and Hemodialysis, Clocheville Hospital, University Hospital of Tours, Tours, France
| | - Véronique Baudouin
- Assistance publique des Hôpitaux de Paris, Department of Pediatric Nephrology, University Hospital Robert Debré, Paris, France
| | - Georges Deschênes
- Assistance publique des Hôpitaux de Paris, Department of Pediatric Nephrology, University Hospital Robert Debré, Paris, France
| | | | - Sandrine Maestri
- Laboratory of Molecular Genetics and Histocompatibility, University Hospital of Brest, Institut National de la Santé et de la Recherche Médicale, U1078, Brest, France
| | - Chiara Visconti
- Assistance Publique des Hôpitaux de Paris, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Department of Pediatric Nephrology, University Hospital Necker-Enfants Malades Paris, France
| | - Olivia Boyer
- Assistance Publique des Hôpitaux de Paris, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Department of Pediatric Nephrology, University Hospital Necker-Enfants Malades Paris, France; Institut National de la Santé et de la Recherche Médicale U1163, Laboratory of Hereditary Kidney Diseases, Université Paris Descartes Sorbonne Paris Cité, Paris, France
| | - Carine Abel
- Department of Medical Genetics, Hospices Civils de Lyon, De la Croix Rousse Hospital Lyon, France
| | - Annie Lahoche
- Pediatric Nephrology Unit Jeanne de Flandre Hospital, Regional University Hospital of Lille, Lille, France
| | - Hanitra Randrianaivo
- Medical Genetics Unit, University Hospital St Pierre La Réunion, La Réunion, France
| | - Lucie Bessenay
- Department of Pediatrics and Pediatric Nephrology University Hospital Estaing, Clermont Ferrand, France
| | - Djalila Mekahli
- Department of Pediatric Nephrology, University Hospitals Leuven, Leuven, Belgium
| | - Ines Ouertani
- Department of Congenital and Inherited Diseases Charles Nicolle Hospital, Tunis, Tunisia
| | - Stéphane Decramer
- Department of Pediatric Nephrology, Children Hospital Toulouse, France; and
| | | | - Emilie Cornec-Le Gall
- Laboratory of Molecular Genetics and Histocompatibility, University Hospital of Brest, Institut National de la Santé et de la Recherche Médicale, U1078, Brest, France
| | - Rémi Salomon
- Assistance Publique des Hôpitaux de Paris, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Department of Pediatric Nephrology, University Hospital Necker-Enfants Malades Paris, France; Institut National de la Santé et de la Recherche Médicale U1163, Laboratory of Hereditary Kidney Diseases, Université Paris Descartes Sorbonne Paris Cité, Paris, France
| | - Claude Ferec
- Laboratory of Molecular Genetics and Histocompatibility, University Hospital of Brest, Institut National de la Santé et de la Recherche Médicale, U1078, Brest, France
| | - Laurence Heidet
- Assistance Publique des Hôpitaux de Paris, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Department of Pediatric Nephrology, University Hospital Necker-Enfants Malades Paris, France;
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125
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Stefanou C, Pieri M, Savva I, Georgiou G, Pierides A, Voskarides K, Deltas C. Co-Inheritance of Functional Podocin Variants with Heterozygous Collagen IV Mutations Predisposes to Renal Failure. Nephron Clin Pract 2015; 130:200-12. [PMID: 26138234 DOI: 10.1159/000432406] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 05/16/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS A subset of patients who present with proteinuria and are diagnosed with focal segmental glomerulosclerosis (FSGS) have inherited heterozygous COL4A3/A4 mutations and are also diagnosed with thin basement membrane nephropathy (TBMN-OMIM: 141200). Two studies showed that co-inheritance of NPHS2-p.Arg229Gln, a podocin variant, may increase the risk for proteinuria and renal function decline. METHODS We hypothesized that additional podocin variants may exert a similar effect. We studied genetically a well-characterized Cypriot TBMN patient cohort by re-sequencing the NPHS2 coding region. We also performed functional studies in cell culture experiments, investigating the interaction of podocin variants with itself and with nephrin. RESULTS Potentially disease-modifying podocin variants were searched for by analyzing NPHS2 in 35 'severe' TBMN patients. One non-synonymous variant, p.Glu237Gln, was detected. Both variants, p.Arg229Gln and p.Glu237Gln, were tested in a larger cohort of 122 TBMN patients, who were categorized as 'mild' or 'severe' based on the presence of microscopic hematuria alone or combined with chronic renal failure and/or proteinuria. Seven 'severe' patients carried either of the 2 variants; none was present in the 'mild' patients (p = 0.05, Pearson χ(2)). The 7 carriers belong in 2 families segregating mutation COL4A3-p.Gly1334Glu. Inheritance of the wild-type (WT) and mutant alleles correlated with the phenotype (combined concordance probability 0.003). Immunofluorescence (IF) experiments after dual co-transfection of WT and mutant podocin suggested altered co-localization of mutant homodimers. IF experiments after co-transfection of WT podocin and nephrin showed normal membrane localization, while both podocin variants interfered with normal trafficking, demonstrating perinuclear staining. Immunoprecipitation experiments showed stronger binding of mutant podocin to WT podocin or nephrin. CONCLUSION The results support the hypothesis that certain hypomorphic podocin variants may act as adverse genetic modifiers when co-inherited with COL4A3/A4 mutations, thus predisposing to FSGS and severe kidney function decline.
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Affiliation(s)
- Charalambos Stefanou
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
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Ong ACM, Devuyst O, Knebelmann B, Walz G. Autosomal dominant polycystic kidney disease: the changing face of clinical management. Lancet 2015; 385:1993-2002. [PMID: 26090645 DOI: 10.1016/s0140-6736(15)60907-2] [Citation(s) in RCA: 202] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Autosomal dominant polycystic kidney disease is the most common inherited kidney disease and accounts for 7-10% of all patients on renal replacement therapy worldwide. Although first reported 500 years ago, this disorder is still regarded as untreatable and its pathogenesis is poorly understood despite much study. During the past 40 years, however, remarkable advances have transformed our understanding of how the disease develops and have led to rapid changes in diagnosis, prognosis, and treatment, especially during the past decade. This Review will summarise the key findings, highlight recent developments, and look ahead to the changes in clinical practice that will likely arise from the adoption of a new management framework for this major kidney disease.
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Affiliation(s)
- Albert C M Ong
- Academic Nephrology Unit, University of Sheffield Medical School, Sheffield, UK; Sheffield Kidney Institute, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK.
| | - Olivier Devuyst
- Institute of Physiology, Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland; Division of Nephrology, Université catholique de Louvain, Brussels, Belgium
| | - Bertrand Knebelmann
- Centre de Reference Maladies Rénales Héréditaires MARHEA, AP-HP, Hopital Necker, Université Paris Descartes, Paris, France
| | - Gerd Walz
- Department of Nephrology, University Freiburg Medical Center, Freiburg, Germany
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127
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Antignac C, Calvet JP, Germino GG, Grantham JJ, Guay-Woodford LM, Harris PC, Hildebrandt F, Peters DJM, Somlo S, Torres VE, Walz G, Zhou J, Yu ASL. The Future of Polycystic Kidney Disease Research--As Seen By the 12 Kaplan Awardees. J Am Soc Nephrol 2015; 26:2081-95. [PMID: 25952256 DOI: 10.1681/asn.2014121192] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Polycystic kidney disease (PKD) is one of the most common life-threatening genetic diseases. Jared J. Grantham, M.D., has done more than any other individual to promote PKD research around the world. However, despite decades of investigation there is still no approved therapy for PKD in the United States. In May 2014, the University of Kansas Medical Center hosted a symposium in Kansas City honoring the occasion of Dr. Grantham's retirement and invited all the awardees of the Lillian Jean Kaplan International Prize for Advancement in the Understanding of Polycystic Kidney Disease to participate in a forward-thinking and interactive forum focused on future directions and innovations in PKD research. This article summarizes the contributions of the 12 Kaplan awardees and their vision for the future of PKD research.
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Affiliation(s)
- Corinne Antignac
- National Institute of Health and Medical Research, Laboratory of Inherited Kidney Diseases, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, and The Department of Genetics, Necker Hospital, Paris, France
| | - James P Calvet
- The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas;
| | - Gregory G Germino
- Kidney Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Jared J Grantham
- The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Lisa M Guay-Woodford
- Center for Translational Science, Children's National Health System, Washington, DC
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Friedhelm Hildebrandt
- Howard Hughes Medical Institute and Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Dorien J M Peters
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Stefan Somlo
- Departments of Internal Medicine and Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Gerd Walz
- Renal Division, Department of Medicine, University Medical Center Freiburg, Freiburg, Germany; and
| | - Jing Zhou
- Harvard Center for Polycystic Kidney Disease Research, Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Alan S L Yu
- The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas;
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128
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Cnossen WR, te Morsche RHM, Hoischen A, Gilissen C, Venselaar H, Mehdi S, Bergmann C, Losekoot M, Breuning MH, Peters DJM, Veltman JA, Drenth JPH. LRP5 variants may contribute to ADPKD. Eur J Hum Genet 2015; 24:237-42. [PMID: 25920554 DOI: 10.1038/ejhg.2015.86] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 02/27/2015] [Accepted: 03/27/2015] [Indexed: 12/13/2022] Open
Abstract
Mutations in Polycystic Kidney Disease proteins (PKD1 or PKD2) are causative for autosomal dominant polycystic kidney disease (ADPKD). However, a small subset of ADPKD probands do not harbor a mutation in any of the known genes. Low density lipoprotein Receptor-related Protein 5 (LRP5) was recently associated with hepatic cystogenesis in isolated polycystic liver disease (PCLD). Here, we demonstrate that this gene may also have a role in unlinked and sporadic ADPKD patients. In a cohort of 79 unrelated patients with adult-onset ADPKD, we identified a total of four different LRP5 variants that were predicted to be pathogenic by in silico tools. One ADPKD patient has a positive family history for ADPKD and variant LRP5 c.1680G>T; p.(Trp560Cys) segregated with the disease. Although also two PKD1 variants probably affecting protein function were identified, luciferase activity assays presented for three LRP5 variants significant decreased signal activation of canonical Wnt signaling. This study contributes to the genetic spectrum of ADPKD. Introduction of the canonical Wnt signaling pathway provides new avenues for the study of the pathophysiology.
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Affiliation(s)
- Wybrich R Cnossen
- Department of Gastroenterology and Hepatology, Institute for Genetic & Metabolic Disease (IGMD), Radboud Institute for Molecular LifeSciences (RIMLS), Radboud university medical center, Nijmegen, The Netherlands
| | - René H M te Morsche
- Department of Gastroenterology and Hepatology, Institute for Genetic & Metabolic Disease (IGMD), Radboud Institute for Molecular LifeSciences (RIMLS), Radboud university medical center, Nijmegen, The Netherlands
| | - Alexander Hoischen
- Department of Human Genetics, Institute for Genetic & Metabolic Disease (IGMD), Radboud Institute for Molecular LifeSciences (RIMLS), Radboud university medical center, Nijmegen, The Netherlands
| | - Christian Gilissen
- Department of Human Genetics, Institute for Genetic & Metabolic Disease (IGMD), Radboud Institute for Molecular LifeSciences (RIMLS), Radboud university medical center, Nijmegen, The Netherlands
| | - Hanka Venselaar
- Center for Molecular and Biomolecular Informatics, Institute for Genetic & Metabolic Disease (IGMD), Radboud Institute for Molecular LifeSciences (RIMLS), Radboud university medical center, Nijmegen, The Netherlands
| | - Soufi Mehdi
- Department of Gastrointestinal and Oncological Surgery, Faculty of Medicine, University Mohammed First, Oujda, Morocco
| | - Carsten Bergmann
- Center for Human Genetics, Bioscientia, Ingelheim, Germany.,Department of Nephrology and Center for Clinical Research, University Hospital Freiburg, Freiburg, Germany
| | - Monique Losekoot
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Martijn H Breuning
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Dorien J M Peters
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Joris A Veltman
- Department of Human Genetics, Institute for Genetic & Metabolic Disease (IGMD), Radboud Institute for Molecular LifeSciences (RIMLS), Radboud university medical center, Nijmegen, The Netherlands.,Department of Clinical Genetics, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Joost P H Drenth
- Department of Gastroenterology and Hepatology, Institute for Genetic & Metabolic Disease (IGMD), Radboud Institute for Molecular LifeSciences (RIMLS), Radboud university medical center, Nijmegen, The Netherlands
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Ali H, Hussain N, Naim M, Zayed M, Al-Mulla F, Kehinde EO, Seaburg LM, Sundsbak JL, Harris PC. A novel PKD1 variant demonstrates a disease-modifying role in trans with a truncating PKD1 mutation in patients with autosomal dominant polycystic kidney disease. BMC Nephrol 2015; 16:26. [PMID: 25880449 PMCID: PMC4357204 DOI: 10.1186/s12882-015-0015-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Accepted: 02/09/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common form of Polycystic Kidney Disease (PKD) and occurs at a frequency of 1/800 to 1/1000 affecting all ethnic groups worldwide. ADPKD shows significant intrafamilial phenotypic variability in the rate of disease progression and extra-renal manifestations, which suggests the involvement of heritable modifier genes. Here we show that the PKD1 gene can act as a disease causing and a disease modifier gene in ADPKD patients. METHODS Clinical evaluation of a family with ADPKD was performed to diagnose and assess disease progression in each individual. PKD1 was genotyped in each individual by targeted sequencing. RESULTS Targeted screening analysis showed that the patients with ADPKD in the family had the PKD1: p.Q2243X nonsense mutation. A more severe disease phenotype, in terms of estimated Glomerular Filtration Rate (eGFR) and total kidney volume, was observed in two patients where in addition to the mutation, they carried a novel PKD1 variant (p.H1769Y). Other patients from the same family carrying only the (p.Q2243X) mutation showed milder disease manifestations. CONCLUSION ADPKD shows significant intrafamilial phenotypic variability that is generally attributed to other modifier genes. In this rare case, we have shown that a variant at PKD1, in trans with the PKD1 mutation, can also act as a modifier gene in ADPKD patients. Understanding the molecular mechanism through which the gene exerts its disease modifying role may aid our understanding of the pathogenesis of ADPKD.
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Affiliation(s)
- Hamad Ali
- Department of Medical Laboratory Sciences, Faculty of Allied Health Sciences, Health Sciences Center, Kuwait University, Jabriya, Kuwait.
| | - Naser Hussain
- Division of Nephrology, Mubarak Al-Kabeer Hospital, Ministry of Health, Jabriya, Kuwait.
| | - Medhat Naim
- Division of Nephrology, Mubarak Al-Kabeer Hospital, Ministry of Health, Jabriya, Kuwait.
| | - Mohamed Zayed
- Department of Radio diagnosis, Mubarak Al-Kabeer Hospital, Ministry of Health, Jabriya, Kuwait.
| | - Fahd Al-Mulla
- Department of Pathology, Faculty of Medicine, Health Sciences Center, Kuwait University, Jabriya, Kuwait.
| | - Elijah O Kehinde
- Department of Surgery, Division of Urology, Faculty of Medicine, Health Sciences Center, Kuwait University, Jabriya, Kuwait.
| | - Lauren M Seaburg
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, USA.
| | - Jamie L Sundsbak
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, USA.
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, USA.
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130
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An efficient and comprehensive strategy for genetic diagnostics of polycystic kidney disease. PLoS One 2015; 10:e0116680. [PMID: 25646624 PMCID: PMC4315576 DOI: 10.1371/journal.pone.0116680] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 12/11/2014] [Indexed: 01/01/2023] Open
Abstract
Renal cysts are clinically and genetically heterogeneous conditions. Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent life-threatening genetic disease and mainly caused by mutations in PKD1. The presence of six PKD1 pseudogenes and tremendous allelic heterogeneity make molecular genetic testing challenging requiring laborious locus-specific amplification. Increasing evidence suggests a major role for PKD1 in early and severe cases of ADPKD and some patients with a recessive form. Furthermore it is becoming obvious that clinical manifestations can be mimicked by mutations in a number of other genes with the necessity for broader genetic testing. We established and validated a sequence capture based NGS testing approach for all genes known for cystic and polycystic kidney disease including PKD1. Thereby, we demonstrate that the applied standard mapping algorithm specifically aligns reads to the PKD1 locus and overcomes the complication of unspecific capture of pseudogenes. Employing careful and experienced assessment of NGS data, the method is shown to be very specific and equally sensitive as established methods. An additional advantage over conventional Sanger sequencing is the detection of copy number variations (CNVs). Sophisticated bioinformatic read simulation increased the high analytical depth of the validation study and further demonstrated the strength of the approach. We further raise some awareness of limitations and pitfalls of common NGS workflows when applied in complex regions like PKD1 demonstrating that quality of NGS needs more than high coverage of the target region. By this, we propose a time- and cost-efficient diagnostic strategy for comprehensive molecular genetic testing of polycystic kidney disease which is highly automatable and will be of particular value when therapeutic options for PKD emerge and genetic testing is needed for larger numbers of patients.
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131
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ARPKD and early manifestations of ADPKD: the original polycystic kidney disease and phenocopies. Pediatr Nephrol 2015; 30:15-30. [PMID: 24584572 PMCID: PMC4240914 DOI: 10.1007/s00467-013-2706-2] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 11/11/2013] [Accepted: 11/12/2013] [Indexed: 12/11/2022]
Abstract
Renal cysts are clinically and genetically heterogeneous conditions. Polycystic kidney disease (PKD) is common and its characterization has paved the way for the identification of a growing number of cilia-related disorders (ciliopathies) of which most show cystic kidneys. While the recessive form of PKD (ARPKD) virtually always presents in childhood, early onset can, in some instances, also occur in the dominant form (ADPKD). Both ADPKD genes (PKD1 and PKD2) can also be inherited in a recessive way, making the story more complex with evidence for a dosage-sensitive network. Several phenocopies are known, and mutations in HNF1ß or genes that typically cause other ciliopathies, such as nephronophthisis, Bardet-Biedl, Joubert syndrome and related disorders, can mimic PKD. An accurate genetic diagnosis is crucial for genetic counseling, prenatal diagnostics, and the clinical management of patients and their families. The increasing number of genes that have to be considered in patients with cystic kidney disease is challenging to address by conventional techniques and largely benefits from next-generation sequencing-based approaches. The parallel analysis of targeted genes considerably increases the detection rate, allows for better interpretation of identified variants, and avoids genetic misdiagnoses.
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132
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Bullich G, Trujillano D, Santín S, Ossowski S, Mendizábal S, Fraga G, Madrid Á, Ariceta G, Ballarín J, Torra R, Estivill X, Ars E. Targeted next-generation sequencing in steroid-resistant nephrotic syndrome: mutations in multiple glomerular genes may influence disease severity. Eur J Hum Genet 2014; 23:1192-9. [PMID: 25407002 PMCID: PMC4538209 DOI: 10.1038/ejhg.2014.252] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 10/14/2014] [Accepted: 10/16/2014] [Indexed: 01/26/2023] Open
Abstract
Genetic diagnosis of steroid-resistant nephrotic syndrome (SRNS) using Sanger sequencing is complicated by the high genetic heterogeneity and phenotypic variability of this disease. We aimed to improve the genetic diagnosis of SRNS by simultaneously sequencing 26 glomerular genes using massive parallel sequencing and to study whether mutations in multiple genes increase disease severity. High-throughput mutation analysis was performed in 50 SRNS and/or focal segmental glomerulosclerosis (FSGS) patients, a validation cohort of 25 patients with known pathogenic mutations, and a discovery cohort of 25 uncharacterized patients with probable genetic etiology. In the validation cohort, we identified the 42 previously known pathogenic mutations across NPHS1, NPHS2, WT1, TRPC6, and INF2 genes. In the discovery cohort, disease-causing mutations in SRNS/FSGS genes were found in nine patients. We detected three patients with mutations in an SRNS/FSGS gene and COL4A3. Two of them were familial cases and presented a more severe phenotype than family members with mutation in only one gene. In conclusion, our results show that massive parallel sequencing is feasible and robust for genetic diagnosis of SRNS/FSGS. Our results indicate that patients carrying mutations in an SRNS/FSGS gene and also in COL4A3 gene have increased disease severity.
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Affiliation(s)
- Gemma Bullich
- 1] Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain [2] Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
| | - Daniel Trujillano
- 1] Genomics and Disease Group, Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona, Catalonia, Spain [2] Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain [3] Hospital del Mar Medical Research Institute (IMIM), Barcelona, Catalonia, Spain [4] CIBER in Epidemiology and Public Health (CIBERESP), Barcelona, Catalonia, Spain
| | - Sheila Santín
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
| | - Stephan Ossowski
- 1] Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain [2] Genomic and Epigenomic Variation in Disease Group, Centre for Genomic Regulation (CRG), Barcelona, Catalonia, Spain
| | - Santiago Mendizábal
- Pediatric Nephrology Department, Hospital Universitario La Fe, Valencia, Spain
| | - Gloria Fraga
- Pediatric Nephrology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Catalonia, Spain
| | - Álvaro Madrid
- Pediatric Nephrology Department, Hospital Vall d'Hebron, Barcelona, Spain
| | - Gema Ariceta
- Pediatric Nephrology Department, Hospital Vall d'Hebron, Barcelona, Spain
| | - José Ballarín
- Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
| | - Roser Torra
- Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
| | - Xavier Estivill
- 1] Genomics and Disease Group, Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona, Catalonia, Spain [2] Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain [3] Hospital del Mar Medical Research Institute (IMIM), Barcelona, Catalonia, Spain [4] CIBER in Epidemiology and Public Health (CIBERESP), Barcelona, Catalonia, Spain
| | - Elisabet Ars
- 1] Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain [2] Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
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Ars E, Bernis C, Fraga G, Martínez V, Martins J, Ortiz A, Rodríguez-Pérez JC, Sans L, Torra R. Spanish guidelines for the management of autosomal dominant polycystic kidney disease. Nephrol Dial Transplant 2014; 29 Suppl 4:iv95-105. [PMID: 25165191 DOI: 10.1093/ndt/gfu186] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent cause of genetic renal disease and accounts for 6-10% of patients on renal replacement therapy (RRT). Very few prospective, randomized trials or clinical studies address the diagnosis and management of this relatively frequent disorder. No clinical guidelines are available to date. This is a consensus statement presenting the recommendations of the Spanish Working Group on Inherited Kidney Diseases, which were agreed to following a literature search and discussions. Levels of evidence found were C and D according to the Centre for Evidence-Based Medicine (University of Oxford). The recommendations relate to, among other topics, the use of imaging and genetic diagnosis, management of hypertension, pain, cyst infections and bleeding, extra-renal involvement including polycystic liver disease and cranial aneurysms, management of chronic kidney disease (CKD) and RRT and management of children with ADPKD. Recommendations on specific ADPKD therapies are not provided since no drug has regulatory approval for this indication.
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Affiliation(s)
- Elisabet Ars
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Spain
| | - Carmen Bernis
- Nephrology Department, Hospital de la Princesa, REDinREN, Madrid, Spain
| | - Gloria Fraga
- Paediatric Nephrology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | | | - Judith Martins
- Nephrology Department, Hospital Universitario de Getafe, Universidad Europea de Madrid, Madrid, Spain
| | - Alberto Ortiz
- Nephrology Department, IIS-Fundacion Jiménez Diaz, Universidad Autónoma de Madrid, IRSIN, REDinREN, Madrid, Spain
| | - José Carlos Rodríguez-Pérez
- Nephrology Department, Hospital Universitario de Gran Canaria Dr. Negrín, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Laia Sans
- Nephrology Department, REDinREN, Hospital del Mar, Barcelona, Spain
| | - Roser Torra
- Inherited Kidney Diseases, Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Spain
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Wentworth JM, Lukic V, Bahlo M, Finlay M, Nguyen C, Morahan G, Harrison LC. Maturity-onset diabetes of the young type 5 in a family with diabetes and mild kidney disease diagnosed by whole exome sequencing. Intern Med J 2014; 44:1137-40. [DOI: 10.1111/imj.12584] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 06/10/2014] [Indexed: 12/17/2022]
Affiliation(s)
- J. M. Wentworth
- Molecular Medicine Division; The Walter and Eliza Hall Institute of Medical Research; Melbourne Victoria
- Department of Diabetes and Endocrinology; Royal Melbourne Hospital; Melbourne Victoria
- Department of Medical Biology; The University of Melbourne; Melbourne Victoria
| | - V. Lukic
- Molecular Medicine Division; The Walter and Eliza Hall Institute of Medical Research; Melbourne Victoria
| | - M. Bahlo
- Molecular Medicine Division; The Walter and Eliza Hall Institute of Medical Research; Melbourne Victoria
- Department of Medical Biology; The University of Melbourne; Melbourne Victoria
- Department of Mathematics and Statistics; The University of Melbourne; Melbourne Victoria
| | - M. Finlay
- Department of Anatomical Pathology; Royal Melbourne Hospital; Melbourne Victoria
| | - C. Nguyen
- Centre for Diabetes Research; The Western Australian Institute for Medical Research
- Centre for Medical Research; University of Western Australia; Perth Western Australia Australia
| | - G. Morahan
- Centre for Diabetes Research; The Western Australian Institute for Medical Research
- Centre for Medical Research; University of Western Australia; Perth Western Australia Australia
| | - L. C. Harrison
- Molecular Medicine Division; The Walter and Eliza Hall Institute of Medical Research; Melbourne Victoria
- Department of Medical Biology; The University of Melbourne; Melbourne Victoria
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Hartung EA, Guay-Woodford LM. Autosomal recessive polycystic kidney disease: a hepatorenal fibrocystic disorder with pleiotropic effects. Pediatrics 2014; 134:e833-45. [PMID: 25113295 PMCID: PMC4143997 DOI: 10.1542/peds.2013-3646] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/07/2014] [Indexed: 12/31/2022] Open
Abstract
Autosomal recessive polycystic kidney disease (ARPKD) is an important cause of chronic kidney disease in children. The care of ARPKD patients has traditionally been the realm of pediatric nephrologists; however, the disease has multisystem effects, and a comprehensive care strategy often requires a multidisciplinary team. Most notably, ARPKD patients have congenital hepatic fibrosis, which can lead to portal hypertension, requiring close follow-up by pediatric gastroenterologists. In severely affected infants, the diagnosis is often first suspected by obstetricians detecting enlarged, echogenic kidneys and oligohydramnios on prenatal ultrasounds. Neonatologists are central to the care of these infants, who may have respiratory compromise due to pulmonary hypoplasia and massively enlarged kidneys. Surgical considerations can include the possibility of nephrectomy to relieve mass effect, placement of dialysis access, and kidney and/or liver transplantation. Families of patients with ARPKD also face decisions regarding genetic testing of affected children, testing of asymptomatic siblings, or consideration of preimplantation genetic diagnosis for future pregnancies. They may therefore interface with genetic counselors, geneticists, and reproductive endocrinologists. Children with ARPKD may also be at risk for neurocognitive dysfunction and may require neuropsychological referral. The care of patients and families affected by ARPKD is therefore a multidisciplinary effort, and the general pediatrician can play a central role in this complex web of care. In this review, we outline the spectrum of clinical manifestations of ARPKD and review genetics of the disease, clinical and genetic diagnosis, perinatal management, management of organ-specific complications, and future directions for disease monitoring and potential therapies.
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Affiliation(s)
- Erum A Hartung
- Division of Nephrology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; and
| | - Lisa M Guay-Woodford
- Center for Translational Science, Children's National Health System, Washington, District of Columbia
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136
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Guay-Woodford LM, Bissler JJ, Braun MC, Bockenhauer D, Cadnapaphornchai MA, Dell KM, Kerecuk L, Liebau MC, Alonso-Peclet MH, Shneider B, Emre S, Heller T, Kamath BM, Murray KF, Moise K, Eichenwald EE, Evans J, Keller RL, Wilkins-Haug L, Bergmann C, Gunay-Aygun M, Hooper SR, Hardy KK, Hartung EA, Streisand R, Perrone R, Moxey-Mims M. Consensus expert recommendations for the diagnosis and management of autosomal recessive polycystic kidney disease: report of an international conference. J Pediatr 2014; 165:611-7. [PMID: 25015577 PMCID: PMC4723266 DOI: 10.1016/j.jpeds.2014.06.015] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 04/24/2014] [Accepted: 06/05/2014] [Indexed: 01/05/2023]
Abstract
Autosomal recessive polycystic kidney disease (ARPKD; MIM 263200) is a severe, typically early onset form of cystic disease that primarily involves the kidneys and biliary tract. Phenotypic expression and age at presentation can be quite variable1 . The incidence of ARPKD is 1 in 20,000 live births2 , and its pleotropic manifestations are potentially life-threatening. Optimal care requires proper surveillance to limit morbidity and mortality, knowledgeable approaches to diagnosis and treatment, and informed strategies to optimize quality of life. Clinical management therefore is ideally directed by multidisciplinary care teams consisting of perinatologists, neonatologists, nephrologists, hepatologists, geneticists, and behavioral specialists to coordinate patient care from the perinatal period to adulthood. In May 2013, an international team of 25 multidisciplinary specialists from the US, Canada, Germany, and the United Kingdom convened in Washington, DC, to review the literature published from 1990 to 2013 and to develop recommendations for diagnosis, surveillance, and clinical management. Identification of the gene PKHD1, and the significant advances in perinatal care, imaging, medical management, and behavioral therapies over the past decade, provide the foundational elements to define diagnostic criteria and establish clinical management guidelines as the first steps towards standardizing the clinical care for ARPKD patients. The key issues discussed included recommendations regarding perinatal interventions, diagnostic criteria, genetic testing, management of renal and biliary-associated morbidities, and behavioral assessment. The meeting was funded by the National Institutes of Health and an educational grant from the Polycystic Kidney Disease Foundation. Here we summarize the discussions and provide an updated set of diagnostic, surveillance, and management recommendations for optimizing the pediatric care of patients with ARPKD. Specialist care of ARPKD-related complications including dialysis, transplantation, and management of severe portal hypertension will be addressed in a subsequent report. Given the paucity of information regarding targeted therapies in ARPKD, this topic was not addressed in this conference.”
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Affiliation(s)
- Lisa M Guay-Woodford
- Center for Translational Science, Children's National Health System, Washington, DC.
| | - John J Bissler
- Division of Pediatric Nephrology, LeBonheur Children's Hospital and St. Jude Children's Research Hospital, Memphis, TN
| | | | - Detlef Bockenhauer
- University College London Institute of Child Health and Nephrology Department, Great Ormond Street Hospital, London, United Kingdom
| | | | - Katherine M Dell
- Department of Pediatrics, Case Western Reserve University and Cleveland Clinic Children's Hospital, Cleveland, OH
| | - Larissa Kerecuk
- Department of Pediatric Nephrology, Birmingham Children's Hospital, National Health Service Foundation Trust, Birmingham, United Kingdom
| | - Max C Liebau
- Department of Pediatrics and Center for Molecular Medicine, Cologne University Hospital, Cologne, Germany
| | - Maria H Alonso-Peclet
- Department of Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Benjamin Shneider
- Division of Pediatric Hepatology, Children's Hospital of Pittsburgh, Pittsburgh, PA
| | - Sukru Emre
- Section of Transplantation and Immunology, Department of Surgery, Yale University School of Medicine, New Haven, CT
| | - Theo Heller
- Liver Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Binita M Kamath
- Division of Gastroenterology, Hepatology, and Nutrition, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Karen F Murray
- Division of Pediatric Gastroenterology and Hepatology, Seattle Children's Hospital, Seattle, WA
| | - Kenneth Moise
- Department of Obstetrics, Gynecology and Reproductive Sciences, The University of Texas Health Science Center at Houston, Houston, TX
| | - Eric E Eichenwald
- Department of Pediatrics, The University of Texas Health Science Center at Houston, Houston, TX
| | - Jacquelyn Evans
- Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Roberta L Keller
- Division of Neonatology, University of California at San Francisco Children's Hospital, San Francisco, CA
| | - Louise Wilkins-Haug
- Division of Maternal Fetal Medicine and Reproductive Genetics, Brigham and Women's Hospital, Boston, MA
| | - Carsten Bergmann
- Bioscientia, Center for Human Genetics, Ingelheim, Germany; Department of Nephrology and Center for Clinical Research, University Hospital Freiburg, Freiburg, Germany
| | - Meral Gunay-Aygun
- Department of Pediatrics, Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD; Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Stephen R Hooper
- Department of Allied Health Sciences and Department of Psychiatry, University of North Carolina School of Medicine, Chapel Hill, NC
| | - Kristina K Hardy
- Department of Neuropsychology, Children's National Health System, Washington, DC
| | - Erum A Hartung
- Division of Nephrology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Randi Streisand
- Center for Translational Science, Children's National Health System, Washington, DC
| | - Ronald Perrone
- Division of Nephrology, Tufts Medical Center, Boston, MA
| | - Marva Moxey-Mims
- Division of Kidney, Urologic, and Hematologic Diseases, NIDDK, National Institutes of Health, Bethesda, MD
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Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in PKD1 or PKD2, which encode polycystin-1 and polycystin-2, respectively. Rodent models are available to study the pathogenesis of polycystic kidney disease (PKD) and for preclinical testing of potential therapies-either genetically engineered models carrying mutations in Pkd1 or Pkd2 or models of renal cystic disease that do not have mutations in these genes. The models are characterized by age at onset of disease, rate of disease progression, the affected nephron segment, the number of affected nephrons, synchronized or unsynchronized cyst formation and the extent of fibrosis and inflammation. Mouse models have provided valuable mechanistic insights into the pathogenesis of PKD; for example, mutated Pkd1 or Pkd2 cause renal cysts but additional factors are also required, and the rate of cyst formation is increased in the presence of renal injury. Animal studies have also revealed complex genetic and functional interactions among various genes and proteins associated with PKD. Here, we provide an update on the preclinical models commonly used to study the molecular pathogenesis of ADPKD and test potential therapeutic strategies. Progress made in understanding the pathophysiology of human ADPKD through these animal models is also discussed.
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Affiliation(s)
- Hester Happé
- Department of Human Genetics, Leiden University Medical Center, S4-P, PO Box 9600, Albinusdreef 2, Leiden, 2333 ZA Leiden, Netherlands
| | - Dorien J M Peters
- Department of Human Genetics, Leiden University Medical Center, S4-P, PO Box 9600, Albinusdreef 2, Leiden, 2333 ZA Leiden, Netherlands
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138
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Gonzalez-Paredes FJ, Ramos-Trujillo E, Claverie-Martin F. Defective pre-mRNA splicing in PKD1 due to presumed missense and synonymous mutations causing autosomal dominant polycystic disease. Gene 2014; 546:243-9. [DOI: 10.1016/j.gene.2014.06.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Revised: 05/21/2014] [Accepted: 06/03/2014] [Indexed: 10/25/2022]
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139
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Bakkaloğlu SA, Kandur Y, Bedir-Demirdağ T, Işık-Gönül İ, Hildebrandt F. Diverse phenotypic expression of NPHP4 mutations in four siblings. Turk J Pediatr 2014; 56:423-426. [PMID: 25818963 PMCID: PMC5839637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Nephronophthisis (NPHP) is an autosomal recessive disease characterized by renal tubular basement membrane disruption, interstitial fibrosis and tubular cysts that progresses to end-stage kidney disease (ESKD). There are also characteristic extrarenal manifestations. Mutations of more than thirteen genes that can cause NPHP have been identified. We herein report four siblings from a consanguineous family, who carried the same NPHP4 mutations but presented with different disease phenotypes ranging from enuresis nocturna to ESKD. Diluted urine and echogenic kidneys in ultrasound examination were consistent, which is typical for 100% of the NPHP cases that have been described. Chronic kidney disease developed in the older two brothers. The observed phenotypic differences are likely to be related to environmental and epigenetic factors, oligogenic inheritance and modifier genes affecting the age of presentation of signs and symptoms. NPHP should be considered as an important cause of CKD in children, which insidiously progresses to ESKD, with no specific therapy available.
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Affiliation(s)
- Sevcan A Bakkaloğlu
- Division of Pediatric Nephrology, Department of Pediatrics, Gazi University, Faculty of Medicine, Ankara, Turkey.
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140
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Harris PC, Torres VE. Genetic mechanisms and signaling pathways in autosomal dominant polycystic kidney disease. J Clin Invest 2014; 124:2315-24. [PMID: 24892705 DOI: 10.1172/jci72272] [Citation(s) in RCA: 236] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Recent advances in defining the genetic mechanisms of disease causation and modification in autosomal dominant polycystic kidney disease (ADPKD) have helped to explain some extreme disease manifestations and other phenotypic variability. Studies of the ADPKD proteins, polycystin-1 and -2, and the development and characterization of animal models that better mimic the human disease, have also helped us to understand pathogenesis and facilitated treatment evaluation. In addition, an improved understanding of aberrant downstream pathways in ADPKD, such as proliferation/secretion-related signaling, energy metabolism, and activated macrophages, in which cAMP and calcium changes may play a role, is leading to the identification of therapeutic targets. Finally, results from recent and ongoing preclinical and clinical trials are greatly improving the prospects for available, effective ADPKD treatments.
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141
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Trujillano D, Bullich G, Ossowski S, Ballarín J, Torra R, Estivill X, Ars E. Diagnosis of autosomal dominant polycystic kidney disease using efficient PKD1 and PKD2 targeted next-generation sequencing. Mol Genet Genomic Med 2014; 2:412-21. [PMID: 25333066 PMCID: PMC4190876 DOI: 10.1002/mgg3.82] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Revised: 03/29/2014] [Accepted: 04/04/2014] [Indexed: 12/21/2022] Open
Abstract
Molecular diagnostics of autosomal dominant polycystic kidney disease (ADPKD) relies on mutation screening of PKD1 and PKD2, which is complicated by extensive allelic heterogeneity and the presence of six highly homologous sequences of PKD1. To date, specific sequencing of PKD1 requires laborious long-range amplifications. The high cost and long turnaround time of PKD1 and PKD2 mutation analysis using conventional techniques limits its widespread application in clinical settings. We performed targeted next-generation sequencing (NGS) of PKD1 and PKD2. Pooled barcoded DNA patient libraries were enriched by in-solution hybridization with PKD1 and PKD2 capture probes. Bioinformatics analysis was performed using an in-house developed pipeline. We validated the assay in a cohort of 36 patients with previously known PKD1 and PKD2 mutations and five control individuals. Then, we used the same assay and bioinformatics analysis in a discovery cohort of 12 uncharacterized patients. We detected 35 out of 36 known definitely, highly likely, and likely pathogenic mutations in the validation cohort, including two large deletions. In the discovery cohort, we detected 11 different pathogenic mutations in 10 out of 12 patients. This study demonstrates that laborious long-range PCRs of the repeated PKD1 region can be avoided by in-solution enrichment of PKD1 and PKD2 and NGS. This strategy significantly reduces the cost and time for simultaneous PKD1 and PKD2 sequence analysis, facilitating routine genetic diagnostics of ADPKD.
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Affiliation(s)
- Daniel Trujillano
- Genomics and Disease Group, Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG) Dr. Aiguader 88, 08003 Barcelona, Catalonia, Spain ; Universitat Pompeu Fabra (UPF) Barcelona, Catalonia, Spain ; Institut Hospital del Mar d'Investigacions Mèdiques (IMIM) 08003 Barcelona, Catalonia, Spain ; CIBER in Epidemiology and Public Health (CIBERESP) Barcelona, Catalonia, Spain
| | - Gemma Bullich
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain ; Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
| | - Stephan Ossowski
- Genomic and Epigenomic Variation in Disease Group, Centre for Genomic Regulation (CRG) Dr. Aiguader 88, 08003 Barcelona, Catalonia, Spain ; Universitat Pompeu Fabra (UPF) Barcelona, Catalonia, Spain
| | - José Ballarín
- Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
| | - Roser Torra
- Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
| | - Xavier Estivill
- Genomics and Disease Group, Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG) Dr. Aiguader 88, 08003 Barcelona, Catalonia, Spain ; Universitat Pompeu Fabra (UPF) Barcelona, Catalonia, Spain ; Institut Hospital del Mar d'Investigacions Mèdiques (IMIM) 08003 Barcelona, Catalonia, Spain ; CIBER in Epidemiology and Public Health (CIBERESP) Barcelona, Catalonia, Spain ; Dexeus Woman's Health, Hospital Universitary Quiron Dexeus Barcelona, Catalonia, Spain
| | - Elisabet Ars
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain ; Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
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142
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Polycystic liver disease: an overview of pathogenesis, clinical manifestations and management. Orphanet J Rare Dis 2014; 9:69. [PMID: 24886261 PMCID: PMC4030533 DOI: 10.1186/1750-1172-9-69] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 04/17/2014] [Indexed: 02/07/2023] Open
Abstract
Polycystic liver disease (PLD) is the result of embryonic ductal plate malformation of the intrahepatic biliary tree. The phenotype consists of numerous cysts spread throughout the liver parenchyma. Cystic bile duct malformations originating from the peripheral biliary tree are called Von Meyenburg complexes (VMC). In these patients embryonic remnants develop into small hepatic cysts and usually remain silent during life. Symptomatic PLD occurs mainly in the context of isolated polycystic liver disease (PCLD) and autosomal dominant polycystic kidney disease (ADPKD). In advanced stages, PCLD and ADPKD patients have massively enlarged livers which cause a spectrum of clinical features and complications. Major complaints include abdominal pain, abdominal distension and atypical symptoms because of voluminous cysts resulting in compression of adjacent tissue or failure of the affected organ. Renal failure due to polycystic kidneys and non-renal extra-hepatic features are common in ADPKD in contrast to VMC and PCLD. In general, liver function remains prolonged preserved in PLD. Ultrasonography is the first instrument to assess liver phenotype. Indeed, PCLD and ADPKD diagnostic criteria rely on detection of hepatorenal cystogenesis, and secondly a positive family history compatible with an autosomal dominant inheritance pattern. Ambiguous imaging or screening may be assisted by genetic counseling and molecular diagnostics. Screening mutations of the genes causing PCLD (PRKCSH and SEC63) or ADPKD (PKD1 and PKD2) confirm the clinical diagnosis. Genetic studies showed that accumulation of somatic hits in cyst epithelium determine the rate-limiting step for cyst formation. Management of adult PLD is based on liver phenotype, severity of clinical features and quality of life. Conservative treatment is recommended for the majority of PLD patients. The primary aim is to halt cyst growth to allow abdominal decompression and ameliorate symptoms. Invasive procedures are required in a selective patient group with advanced PCLD, ADPKD or liver failure. Pharmacological therapy by somatostatin analogues lead to beneficial outcome of PLD in terms of symptom relief and liver volume reduction.
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143
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Novel mutations of PKD genes in the Czech population with autosomal dominant polycystic kidney disease. BMC MEDICAL GENETICS 2014; 15:41. [PMID: 24694054 PMCID: PMC3992149 DOI: 10.1186/1471-2350-15-41] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 03/10/2014] [Indexed: 11/10/2022]
Abstract
BACKGROUND Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary renal disorder caused by mutation in either one of two genes, PKD1 and PKD2. High structural and sequence complexity of PKD genes makes the mutational diagnostics of ADPKD challenging. The present study is the first detailed analysis of both PKD genes in a cohort of Czech patients with ADPKD using High Resolution Melting analysis (HRM) and Multiplex Ligation-dependent Probe Amplification (MLPA). METHODS The mutational analysis of PKD genes was performed in a set of 56 unrelated patients. For mutational screening of the PKD1 gene, the long-range PCR (LR-PCR) strategy followed by nested PCR was used. Resulting PCR fragments were analyzed by HRM; the positive cases were reanalyzed and confirmed by direct sequencing. Negative samples were further examined for sequence changes in the PKD2 gene by the method of HRM and for large rearrangements of both PKD1 and PKD2 genes by MLPA. RESULTS Screening of the PKD1 gene revealed 36 different likely pathogenic germline sequence changes in 37 unrelated families/individuals. Twenty-five of these sequence changes were described for the first time. Moreover, a novel large deletion was found within the PKD1 gene in one patient. Via the mutational analysis of the PKD2 gene, two additional likely pathogenic mutations were detected. CONCLUSIONS Probable pathogenic mutation was detected in 71% of screened patients. Determination of PKD mutations and their type and localization within corresponding genes could help to assess clinical prognosis of ADPKD patients and has major benefit for prenatal and/or presymptomatic or preimplantational diagnostics in affected families as well.
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144
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Yu C, Li J, Yuan Z, Liu S, Zou L. Two novel mutations affecting the same splice site of PKD1 correlate with different phenotypes in ADPKD. Ren Fail 2014; 36:687-93. [PMID: 24575920 DOI: 10.3109/0886022x.2014.890010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Genetic heterogeneity is the main factor for significant variation in the course of autosomal dominant polycystic kidney disease (ADPKD). PKD1 patients have more severe renal outcomes compared with PKD2 patients. Co-inheritance of a mutation in both genes is associated with more severe phenotypes than that found with either mutation alone. However, the genotype-phenotype relationship is far from clear in ADPKD. Here, we observed two novel mutations, PKD1:c.12444G > A and PKD1:c.12444 + 1G > A, which alter the same splice donor site of intron 45, correlate with different renal outcomes. To explain the phenomenon, we analyzed the genic and allelic background of the patients, as well as the genetic modifiers, DKK3 and HNF-1β as suggested. Only PKD1 variants were found, which highlights the allelic influence of PKD1 gene to be the last candidate factor. Segregation analysis, online mutation prediction, and recurrence mutation searching were applied to sort the variants. However, none of variants was found to be damaging or associated with the disease except PKD1:c.12444G > A and PKD1:c.12444 + 1G > A. Cloning and sequencing of the mutated cDNA sequences had shown unexpected different splicing effects caused by the mutations. PKD1:c.12444 + 1G > A definitely destroyed the native splice site and created a novel donor site with truncating effect on PC1. In contrast, PKD1:c.12444G > A mainly weakened the site and decreased the expression of normal PC1. Since PC1 negatively regulates cell proliferation in the process of cyst formation and enlargement, our observation may explain this new genotype-phenotype correlation and help to improve genetic counseling and diagnosis of the disease.
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Affiliation(s)
- Chaowen Yu
- Center for Clinical Molecular Medicine, Children's Hospital, Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders , Chongqing , P.R. China and
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145
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Krall P, Pineda C, Ruiz P, Ejarque L, Vendrell T, Camacho JA, Mendizábal S, Oliver A, Ballarín J, Torra R, Ars E. Cost-effective PKHD1 genetic testing for autosomal recessive polycystic kidney disease. Pediatr Nephrol 2014; 29:223-34. [PMID: 24162162 DOI: 10.1007/s00467-013-2657-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 09/30/2013] [Accepted: 10/04/2013] [Indexed: 12/22/2022]
Abstract
BACKGROUND Genetic diagnosis of autosomal recessive polycystic kidney disease (ARPKD) is challenging due to the length and allelic heterogeneity of the PKHD1 gene. Mutations appear to be clustered at specific exons, depending on the geographic origin of the patient. We aimed to identify the PKHD1 exons most likely mutated in Spanish ARPKD patients. METHODS Mutation analysis was performed in 50 ARPKD probands and nine ARPKD-suspicious patients by sequencing PKHD1 exons arranged by their reported mutation frequency. Haplotypes containing the most frequent mutations were analyzed. Other PKD genes (HNF1B, PKD1, PKD2) were sequenced in PKHD1-negative cases. RESULTS Thirty-six different mutations (concentrated in 24 PKHD1 exons) were detected, giving a mutation detection rate of 86%. The screening of five exons (58, 32, 34, 36, 37) yielded a 54% chance of detecting one mutation; the screening of nine additional exons (3, 9, 39, 61, 5, 22, 26, 41, 57) increased the chance to 76%. The c.9689delA mutation was present in 17 (34%) patients, all of whom shared the same haplotype. Two HNF1B mutations and one PKD1 variant were detected in negative cases. CONCLUSIONS Establishing a PKHD1 exon mutation profile in a specific population and starting the analysis with the most likely mutated exons might significantly enhance the efficacy of genetic testing in ARPKD. Analysis of other PKD genes might be considered, especially in suspicious cases.
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Affiliation(s)
- Paola Krall
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, C/Cartagena, 340-350, 08025, Barcelona, Spain
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146
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Fedeles SV, Gallagher AR, Somlo S. Polycystin-1: a master regulator of intersecting cystic pathways. Trends Mol Med 2014; 20:251-60. [PMID: 24491980 DOI: 10.1016/j.molmed.2014.01.004] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 01/04/2014] [Accepted: 01/07/2014] [Indexed: 12/13/2022]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the most common potentially lethal monogenic disorder, with more than 12 million cases worldwide. The two causative genes for ADPKD, PKD1 and PKD2, encode protein products polycystin-1 (PC1) and polycystin-2 (PC2 or TRPP2), respectively. Recent data have shed light on the role of PC1 in regulating the severity of the cystic phenotypes in ADPKD, autosomal recessive polycystic kidney disease (ARPKD), and isolated autosomal dominant polycystic liver disease (ADPLD). These studies showed that the rate for cyst growth was a regulated trait, a process that can be either sped up or slowed down by alterations in functional PC1. These findings redefine the previous understanding that cyst formation occurs as an 'on-off' process. Here, we review these and other related studies with an emphasis on their translational implications for polycystic diseases.
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Affiliation(s)
- Sorin V Fedeles
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.
| | - Anna-Rachel Gallagher
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Stefan Somlo
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA.
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147
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Eneman B, Mekahli D, Audrezet MP, Lerut E, Van Damme-Lombaerts R, Van den Heuvel L, Levtchenko E. An unusual presentation of Denys-Drash syndrome due to bigenic disease. Pediatrics 2014; 133:e252-6. [PMID: 24379226 DOI: 10.1542/peds.2013-1524] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We report a case of Denys-Drash syndrome (DDS) in a 3-month-old girl presenting with bilateral renal cortical cysts mimicking polycystic kidney disease. Genetic analysis revealed a de novo heterozygous missense mutation c.1186G>A (p.Asp396Asn) in the WT1 gene, confirming the diagnosis of DDS. Because multiple renal cysts have never been reported in DDS, we explored several genes responsible for these renal manifestations, such as HNF-1β, PAX2, PKD1, and PKD2. Remarkably, we identified a heterozygous missense variant c.12439A>G (p.Lys4147Glu) in the PKD1 gene. The same variant was found in the patient's mother, who had no renal cysts, and in the grandfather, who had several renal cysts. Mutation prediction programs classified the c.12439A>G variant as being "likely pathogenic." We hypothesize that the severe cystic phenotype in the index patient could be due to the WT1 mutation, enhancing pathogenicity of the "hypomorph" PKD1 allele. A possible role for Wilms tumor suppressor 1 (WT1) in renal cyst development should be considered. From a conceptual point of view, this case shows that an unusual presentation of a known genetic syndrome might point to bigenic inheritance, with unexpected interference of mutated genes causing an uncommon clinical phenotype.
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Affiliation(s)
- Benedicte Eneman
- Pediatric Nephrology, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium.
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148
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Bilineal inheritance of PKD1 abnormalities mimicking autosomal recessive polycystic disease. Pediatr Nephrol 2013; 28:2217-20. [PMID: 23624871 DOI: 10.1007/s00467-013-2484-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 03/20/2013] [Accepted: 04/03/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Dominant polycystic kidney disease is common and usually presents clinically in adulthood. Recessive polycystic kidney disease is much less common and frequently presents antenatally or in the neonatal period with severe renal involvement. These are usually thought of as clinically distinct entities but diagnostic confusion is not infrequent. CASE-DIAGNOSIS/TREATMENT We describe an infant with antenatally diagnosed massive renal enlargement and oligohydramnios with no resolvable cysts on ultrasound scanning. He underwent bilateral nephrectomy because of respiratory compromise and poor renal function but died subsequently of overwhelming sepsis. Genetic analysis revealed that he had bilineal inheritance of abnormalities of PKD1 and no demonstrable abnormalities of PKD2 or PKHD1. CONCLUSIONS Biallelic inheritance of abnormalities of PKD1 may causextremely severe disease resembling autosomal recessive polycystic kidney disease (ARPKD) which can result indiagnostic confusion. Accurate diagnosis is essential forgenetic counseling [corrected].
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149
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Looking at the (w)hole: magnet resonance imaging in polycystic kidney disease. Pediatr Nephrol 2013; 28:1771-83. [PMID: 23239392 DOI: 10.1007/s00467-012-2370-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 10/23/2012] [Accepted: 10/24/2012] [Indexed: 12/29/2022]
Abstract
Inherited cystic kidney diseases, including autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD), are the most common monogenetic causes of end-stage renal disease (ESRD) in children and adults. While ARPKD is a rare and usually severe pediatric disease, the more common ADPKD typically shows a slowly progressive course leading to ESRD in adulthood. At the present time there is no established disease-modifying treatment for either ARPKD or ADPKD. Various therapeutic approaches are currently under investigation, such as V2 receptor antagonists, somatostatins, and mTOR inhibitors. Renal function remains stable for decades in ADPKD, and thus clinically meaningful surrogate markers to assess therapeutic efficacy are needed. Various studies have pointed out that total kidney volume (TKV) is a potential surrogate parameter for disease severity in ADPKD. Recent trials have therefore measured TKV by magnet resonance imaging (MRI) to monitor and to predict disease progression. Here, we discuss novel insights on polycystic kidney disease (PKD), the value of MRI, and the measurement of TKV in the diagnosis and follow-up of PKD, as well as novel emerging therapeutic strategies for ADPKD.
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150
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miR-17~92 miRNA cluster promotes kidney cyst growth in polycystic kidney disease. Proc Natl Acad Sci U S A 2013; 110:10765-70. [PMID: 23759744 DOI: 10.1073/pnas.1301693110] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Polycystic kidney disease (PKD), the most common genetic cause of chronic kidney failure, is characterized by the presence of numerous, progressively enlarging fluid-filled cysts in the renal parenchyma. The cysts arise from renal tubules and are lined by abnormally functioning and hyperproliferative epithelial cells. Despite recent progress, no Food and Drug Administration-approved therapy is available to retard cyst growth. MicroRNAs (miRNAs) are short noncoding RNAs that inhibit posttranscriptional gene expression. Dysregulated miRNA expression is observed in PKD, but whether miRNAs are directly involved in kidney cyst formation and growth is not known. Here, we show that miR-17∼92, an oncogenic miRNA cluster, is up-regulated in mouse models of PKD. Kidney-specific transgenic overexpression of miR-17∼92 produces kidney cysts in mice. Conversely, kidney-specific inactivation of miR-17∼92 in a mouse model of PKD retards kidney cyst growth, improves renal function, and prolongs survival. miR-17∼92 may mediate these effects by promoting proliferation and through posttranscriptional repression of PKD genes Pkd1, Pkd2, and hepatocyte nuclear factor-1β. These studies demonstrate a pathogenic role of miRNAs in mouse models of PKD and identify miR-17∼92 as a therapeutic target in PKD. Our results also provide a unique hypothesis for disease progression in PKD involving miRNAs and regulation of PKD gene dosage.
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