1
|
Hermle T, Schneider R, Schapiro D, Braun DA, van der Ven AT, Warejko JK, Daga A, Widmeier E, Nakayama M, Jobst-Schwan T, Majmundar AJ, Ashraf S, Rao J, Finn LS, Tasic V, Hernandez JD, Bagga A, Jalalah SM, El Desoky S, Kari JA, Laricchia KM, Lek M, Rehm HL, MacArthur DG, Mane S, Lifton RP, Shril S, Hildebrandt F. GAPVD1 and ANKFY1 Mutations Implicate RAB5 Regulation in Nephrotic Syndrome. J Am Soc Nephrol 2018; 29:2123-2138. [PMID: 29959197 PMCID: PMC6065084 DOI: 10.1681/asn.2017121312] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 05/24/2018] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Steroid-resistant nephrotic syndrome (SRNS) is a frequent cause of CKD. The discovery of monogenic causes of SRNS has revealed specific pathogenetic pathways, but these monogenic causes do not explain all cases of SRNS. METHODS To identify novel monogenic causes of SRNS, we screened 665 patients by whole-exome sequencing. We then evaluated the in vitro functional significance of two genes and the mutations therein that we discovered through this sequencing and conducted complementary studies in podocyte-like Drosophila nephrocytes. RESULTS We identified conserved, homozygous missense mutations of GAPVD1 in two families with early-onset NS and a homozygous missense mutation of ANKFY1 in two siblings with SRNS. GAPVD1 and ANKFY1 interact with the endosomal regulator RAB5. Coimmunoprecipitation assays indicated interaction between GAPVD1 and ANKFY1 proteins, which also colocalized when expressed in HEK293T cells. Silencing either protein diminished the podocyte migration rate. Compared with wild-type GAPVD1 and ANKFY1, the mutated proteins produced upon ectopic expression of GAPVD1 or ANKFY1 bearing the patient-derived mutations exhibited altered binding affinity for active RAB5 and reduced ability to rescue the knockout-induced defect in podocyte migration. Coimmunoprecipitation assays further demonstrated a physical interaction between nephrin and GAPVD1, and immunofluorescence revealed partial colocalization of these proteins in rat glomeruli. The patient-derived GAPVD1 mutations reduced nephrin-GAPVD1 binding affinity. In Drosophila, silencing Gapvd1 impaired endocytosis and caused mistrafficking of the nephrin ortholog. CONCLUSIONS Mutations in GAPVD1 and probably in ANKFY1 are novel monogenic causes of NS. The discovery of these genes implicates RAB5 regulation in the pathogenesis of human NS.
Collapse
Affiliation(s)
- Tobias Hermle
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
- Renal Division, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ronen Schneider
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - David Schapiro
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Daniela A Braun
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Amelie T van der Ven
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jillian K Warejko
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ankana Daga
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Eugen Widmeier
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Makiko Nakayama
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Tilman Jobst-Schwan
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Amar J Majmundar
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Shazia Ashraf
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jia Rao
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Laura S Finn
- Department of Pathology, Seattle Children's Hospital, University of Washington, Seattle, Washington
| | - Velibor Tasic
- Department of Pediatric Nephrology, Medical Faculty Skopje, University Children's Hospital, Skopje, Macedonia
| | - Joel D Hernandez
- Department of Pediatric Nephrology, Providence Sacred Heart Medical Center and Children's Hospital, Spokane, Washington
| | - Arvind Bagga
- Division of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | | | - Sherif El Desoky
- Pediatric Nephrology Center of Excellence and Pediatric Department, Faculty of Medicine, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
| | - Jameela A Kari
- Pediatric Nephrology Center of Excellence and Pediatric Department, Faculty of Medicine, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
| | - Kristen M Laricchia
- Broad Center for Mendelian Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts
| | - Monkol Lek
- Broad Center for Mendelian Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts
| | - Heidi L Rehm
- Broad Center for Mendelian Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts
| | - Daniel G MacArthur
- Broad Center for Mendelian Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts
| | - Shrikant Mane
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut; and
| | - Richard P Lifton
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut; and
- Laboratory of Human Genetics and Genomics, The Rockefeller University, New York, New York
| | - Shirlee Shril
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Friedhelm Hildebrandt
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts;
| |
Collapse
|
2
|
Wright E, Fischbach M, Zaloszyc A, Paglialonga F, Aufricht C, Dufek S, Bakkaloğlu S, Klaus G, Zurowska A, Ekim M, Ariceta G, Holtta T, Jankauskiene A, Schmitt CP, Stefanidis CJ, Walle JV, Vondrak K, Edefonti A, Shroff R. Hemodialysis in children with ventriculoperitoneal shunts: prevalence, management and outcomes. Pediatr Nephrol 2016; 31:137-43. [PMID: 26386590 DOI: 10.1007/s00467-015-3204-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 08/13/2015] [Accepted: 08/28/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND Hemodialysis (HD) in children with a concomitant ventriculoperitoneal shunt (VPS) is rare. Registry data suggest that peritoneal dialysis with a VPS is safe, but little is known about HD in the presence of a VPS. METHODS We performed a 10-year survey to determine the prevalence of a VPS, complications and outcome in children with a VPS on HD in 15 dialysis units from the 13 countries participating in the European Pediatric Dialysis Working Group. RESULTS Eleven cases of HD with a VPS were reported (prevalence 1.33 %; 328 patient-months) and compared with prospective Registry data. The median age at start of dialysis was 9.6 [inter-quartile range (IQR) 1.0-15.0] years and median HD vintage was 2.4 (IQR 1.7-3.0) years. Dialysis was performed through a central venous line (CVL) and through an arteriovenous fistula in six and five children, respectively. Three CVL infections occurred in two children, but these children did not develop VPS infections or meningitis. Symptoms of hemodynamic instability were reported in six (55 %) children at least once per week, with hypotension or hypertension occurring in four of these children and nausea, vomiting and headaches occurring in two; four other children reported less frequent symptoms. Seizures on dialysis occurred in two children, at a frequency of less than once per month, with one child also experiencing visual disturbances. During follow-up (median 4.0; IQR 0.38-7.63 years), three children remained on HD and eight had a functioning transplant. No patients were switched to PD. CONCLUSIONS Hemodialysis in children with a VPS is safe, but associated with frequent symptoms of hemodynamic instability. No episodes of VPS infection or meningitis were seen among the children in the survey, not even in those with CVL sepsis.
Collapse
Affiliation(s)
- Elizabeth Wright
- Nephro-Urology Unit, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, WC1N 3JH, UK
| | | | | | - Fabio Paglialonga
- Fondazione IRCCS Ca' Grande Ospedale Maggiore Policlinico, Milan, Italy
| | | | - Stephanie Dufek
- Nephro-Urology Unit, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, WC1N 3JH, UK
| | | | | | | | | | - Gema Ariceta
- University Hospital Vall d'Hebron, Barcelona, Spain
| | | | | | | | | | | | | | - Alberto Edefonti
- Fondazione IRCCS Ca' Grande Ospedale Maggiore Policlinico, Milan, Italy
| | - Rukshana Shroff
- Nephro-Urology Unit, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, WC1N 3JH, UK.
| | | |
Collapse
|
4
|
Nephrotic syndrome in infancy can spontaneously resolve. Pediatr Nephrol 2011; 26:1897-901. [PMID: 21611885 DOI: 10.1007/s00467-011-1911-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 03/22/2011] [Accepted: 04/28/2011] [Indexed: 02/08/2023]
Abstract
Nephrotic syndrome in the first year of life (NSFL) is a heterogeneous group of disorders, the management of which is supportive, as most patients do not respond to immunosuppression. Prognosis is guarded, as the syndrome tends to lead to end-stage renal failure. We describe four cases, all of which went into spontaneous remission. These patients had severe nephrosis that began postnatally at ages 15 days to 7 months and had preceding symptoms of viral infections. One infant had proven pertussis and required ventilation for respiratory failure. Renal biopsies showed varying degrees of mesangial expansion and increased cellularity. Two biopsies showed mild mesangial sclerosis and the other two only scattered globally sclerosed glomeruli. Supportive treatment was started with 20% albumin infusions, diuretics, penicillin, and thyroxine. Angiotensin-converting enzyme (ACE) inhibitors were used to reduce proteinuria in all infants, and one was also treated with indomethacin. The nephrosis gradually resolved, and protein-lowering medications were successfully weaned completely 5-30 months after presentation. The patients were protein free with normal renal function at last follow-up. Investigations including viral studies and autoimmune profiles were negative. Genetic studies for NPHS1, NPHS2, WT1, and LAM-β were negative. We therefore describe a subgroup of NSFL with good prognosis associated with infectious prodromes. This is also the first-described case of pertussis causing nephrotic syndrome.
Collapse
|
5
|
Benoit G, Machuca E, Antignac C. Hereditary nephrotic syndrome: a systematic approach for genetic testing and a review of associated podocyte gene mutations. Pediatr Nephrol 2010; 25:1621-32. [PMID: 20333530 PMCID: PMC2908444 DOI: 10.1007/s00467-010-1495-0] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 02/04/2010] [Accepted: 02/08/2010] [Indexed: 11/30/2022]
Abstract
Several genes have been implicated in genetic forms of nephrotic syndrome occurring in children. It is now known that the phenotypes associated with mutations in these genes display significant variability, rendering genetic testing and counselling a more complex task. This review will focus on the recent clinical findings associated with those genes known to be involved in isolated steroid-resistant nephrotic syndrome in children and, thereby, propose an approach for appropriate mutational screening. The recurrence of proteinuria after transplantation in patients with hereditary forms of nephrotic syndrome will also be discussed.
Collapse
Affiliation(s)
- Geneviève Benoit
- Inserm, U983, Hôpital Necker-Enfants Malades, Paris, France ,CHU Sainte-Justine, Université de Montréal, Montréal, Canada
| | - Eduardo Machuca
- Inserm, U983, Hôpital Necker-Enfants Malades, Paris, France ,Pontificia Universidad Católica de Chile, Escuela de Medicina, Santiago, Chile
| | - Corinne Antignac
- Inserm, U983, Hôpital Necker-Enfants Malades, Paris, France ,Faculté de Médecine Paris Descartes, Université Paris Descartes, Paris, France ,Département de Génétique, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France ,Inserm, U983, 6e étage, Tour Lavoisier, Hôpital Necker-Enfants Malades, 149 rue de Sèvres, 75015 Paris, France
| |
Collapse
|