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Baylarov R, Senol O, Atan M, Berdeli A. NPHS2 gene mutations in azerbaijani children with steroid-resistant nephrotic syndrome. SAUDI JOURNAL OF KIDNEY DISEASES AND TRANSPLANTATION 2021; 31:144-149. [PMID: 32129207 DOI: 10.4103/1319-2442.279934] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Nephrotic syndrome (NS) is characterized by proteinuria in children. Steroid- resistant NS (SRNS) is defined by resistance to standard steroid therapy, and it continues to be one of the most common causes of chronic renal failure. Molecular studies have revealed specialized molecules in different regions of the podocytes that play a role in proteinuria. Mutations in NPHS2 that encode for podocin constitute a frequent cause of SRNS worldwide. This study aimed to screen for podocin mutations in Azerbaijani patients with SRNS. Our study included 21 pediatric patients with SRNS aged between 0 and 18 years and the same number of healthy control groups. Mutational analysis of the NPHS2 gene was performed using direct sequencing methods. Disease-causing mutations in the NPHS2 gene were detected in eight patients (38%). Thirteen patients (62%) had NPHS2 mutations without causing the disease. Two patients had p.Val290Met homozygous mutation; two had p.Arg229Gln homozygous mutations; and one each had p.Pro20Leu homozygote, p.Leu169Pro homozygote, p.Arg138Gln homozygote, and p.Arg168His homozygous mutations. When we correlated the NPHS2 mutation status with disease progression, there was a statistically significant increase in serum creatinine, proteinuria, and serum albumin values in patients with NPHS2 gene mutations compared to the group without mutation (P <0.05). Our study concludes that mutations of the NPHS2 gene (38%) are heterogeneous in Azerbaijani SRNS patients. Based on our results, we support a model in which ethnicity plays an important role in certain NPHS2 mutations. NPHS2 mutation analysis may help to better predict the course of the disease, remove unnecessary long-term immunosuppressive therapy, and develop specific treatment.
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Affiliation(s)
- Rauf Baylarov
- Department of Pediatrics, Pediatric Nephrology Division, Azerbaijan State Medical University, Baku, Azerbaijan
| | - Ozgur Senol
- Department of Pediatric Molecular Medicine Laboratory, Ege University Medical Faculty, Izmir, Turkey
| | - Merve Atan
- Department of Pediatric Molecular Medicine Laboratory, Ege University Medical Faculty, Izmir, Turkey
| | - Afig Berdeli
- Department of Pediatric Molecular Medicine Laboratory, Ege University Medical Faculty, Izmir, Turkey
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Trautmann A, Vivarelli M, Samuel S, Gipson D, Sinha A, Schaefer F, Hui NK, Boyer O, Saleem MA, Feltran L, Müller-Deile J, Becker JU, Cano F, Xu H, Lim YN, Smoyer W, Anochie I, Nakanishi K, Hodson E, Haffner D. IPNA clinical practice recommendations for the diagnosis and management of children with steroid-resistant nephrotic syndrome. Pediatr Nephrol 2020; 35:1529-1561. [PMID: 32382828 PMCID: PMC7316686 DOI: 10.1007/s00467-020-04519-1] [Citation(s) in RCA: 156] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/07/2020] [Accepted: 02/21/2020] [Indexed: 02/06/2023]
Abstract
Idiopathic nephrotic syndrome newly affects 1-3 per 100,000 children per year. Approximately 85% of cases show complete remission of proteinuria following glucocorticoid treatment. Patients who do not achieve complete remission within 4-6 weeks of glucocorticoid treatment have steroid-resistant nephrotic syndrome (SRNS). In 10-30% of steroid-resistant patients, mutations in podocyte-associated genes can be detected, whereas an undefined circulating factor of immune origin is assumed in the remaining ones. Diagnosis and management of SRNS is a great challenge due to its heterogeneous etiology, frequent lack of remission by further immunosuppressive treatment, and severe complications including the development of end-stage kidney disease and recurrence after renal transplantation. A team of experts including pediatric nephrologists and renal geneticists from the International Pediatric Nephrology Association (IPNA), a renal pathologist, and an adult nephrologist have now developed comprehensive clinical practice recommendations on the diagnosis and management of SRNS in children. The team performed a systematic literature review on 9 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, formulated recommendations and formally graded them at a consensus meeting, with input from patient representatives and a dietician acting as external advisors and a voting panel of pediatric nephrologists. Research recommendations are also given.
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Affiliation(s)
- Agnes Trautmann
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany
| | - Marina Vivarelli
- Department of Pediatric Subspecialties, Division of Nephrology and Dialysis, Bambino Gesù Pediatric Hospital and Research Center, Rome, Italy
| | - Susan Samuel
- Department of Pediatrics, Section of Pediatric Nephrology, Alberta Children's Hospital, University of Calgary, Calgary, Canada
| | - Debbie Gipson
- Division of Nephrology, University of Michigan, Ann Arbor, MI, USA
| | - Aditi Sinha
- Department of Pediatrics, Division of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | - Franz Schaefer
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany
| | - Ng Kar Hui
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Olivia Boyer
- Laboratory of Hereditary Kidney Diseases, Imagine Institute, INSERM U1163, Paris Descartes University, Paris, France
- Department of Pediatric Nephrology, Reference Center for Idiopathic Nephrotic Syndrome in Children and Adults, Necker Hospital, APHP, 75015, Paris, France
| | - Moin A Saleem
- Department of Pediatric Nephrology, Bristol Royal Hospital for Children, University of Bristol, Bristol, UK
| | - Luciana Feltran
- Hospital Samaritano and HRim/UNIFESP, Federal University of São Paulo, São Paulo, Brazil
| | | | - Jan Ulrich Becker
- Institute of Pathology, University Hospital of Cologne, Cologne, Germany
| | - Francisco Cano
- Department of Nephrology, Luis Calvo Mackenna Children's Hospital, University of Chile, Santiago, Chile
| | - Hong Xu
- Department of Nephrology, Children's Hospital of Fudan University, Shanghai, China
| | - Yam Ngo Lim
- Department of Pediatrics, Prince Court Medical Centre, Kuala Lumpur, Malaysia
| | - William Smoyer
- The Research Institute at Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | - Ifeoma Anochie
- Department of Paediatrics, University of Port Harcourt Teaching Hospital, Port Harcourt, Rivers State, Nigeria
| | - Koichi Nakanishi
- Department of Child Health and Welfare (Pediatrics), Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Elisabeth Hodson
- Cochrane Kidney and Transplant, Centre for Kidney Research, The Children's Hospital at Westmead and the Sydney School of Public Health, University of Sydney, Sydney, Australia
| | - Dieter Haffner
- Department of Paediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School Children's Hospital, Hannover, Germany.
- Department of Paediatric Kidney, Liver and Metabolic Diseases, Paediatric Research Center, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
- Center for Rare Diseases, Hannover Medical School Children's Hospital, Hannover, Germany.
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3
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Park E, Ahn YH, Kang HG, Miyake N, Tsukaguchi H, Cheong HI. NUP107 mutations in children with steroid-resistant nephrotic syndrome. Nephrol Dial Transplant 2018; 32:1013-1017. [PMID: 27190346 DOI: 10.1093/ndt/gfw103] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 04/09/2016] [Indexed: 11/14/2022] Open
Abstract
Background NUP107 is a novel gene associated with autosomal recessive steroid-resistant nephrotic syndrome (SRNS) with focal segmental glomerulosclerosis (FSGS) in children. The frequency of NUP107 mutations in children with SR-FSGS remains unknown. Methods Nine families with two siblings affected by childhood-onset SRNS or proteinuria were recruited. FSGS was confirmed by a kidney biopsy in at least one affected sibling in all families. Additionally, 69 sporadic pediatric cases with biopsy-proven SR-FSGS who had not responded to any treatment were included. All coding exons with flanking introns of the NUP107 gene were amplified using polymerase chain reaction and directly sequenced. Results Biallelic NUP107 mutations were detected in four pairs (44.4%) of siblings from the familial cases and three (4.3%) sporadic cases. All affected patients harbored the p.Asp831Ala mutation in one allele and a truncating or abnormal splicing mutation in the other allele. NUP107 mutation-positive patients showed an earlier onset age (39.4 ± 13.1 versus 76.8 ± 50.0 months, P= 0.027) and more rapid progression to end-stage renal disease (at the ages of 58.9 ± 23.4 versus 123.1 ± 62.7 months, P < 0.001) compared with mutation-negative patients. None of the eight mutation-positive cases, who underwent kidney transplantation, showed recurrence of FSGS in the graft kidney, while 35.3% of mutation-negative cases showed recurrence of FSGS. Conclusions An unexpectedly high incidence of NUP107 mutations was observed in Korean children with SR-FSGS. Initial genetic screening of children with SR-FSGS should include the NUP107 gene, at least in Korea. Further studies are necessary to determine the incidences of NUP107 mutations in other countries.
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Affiliation(s)
- Eujin Park
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
| | - Yo Han Ahn
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
| | - Hee Gyung Kang
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea.,Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hiroyasu Tsukaguchi
- Second Department of Internal Medicine, Kansai Medical University, Osaka, Japan
| | - Hae Il Cheong
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea.,Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea.,Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea
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Recurrence and Treatment after Renal Transplantation in Children with FSGS. BIOMED RESEARCH INTERNATIONAL 2016; 2016:6832971. [PMID: 27213154 PMCID: PMC4860214 DOI: 10.1155/2016/6832971] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 03/14/2016] [Accepted: 04/04/2016] [Indexed: 01/15/2023]
Abstract
Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage renal disease and a common pathologic diagnosis of idiopathic nephrotic syndrome (NS), especially in steroid-resistant cases. FSGS is known to recur after kidney transplantation, frequently followed by graft loss. However, not all patients with FSGS suffer from recurrence after kidney transplantation, and genetic and secondary FSGS have a negligible risk of recurrence. Furthermore, many cases of recurrence achieve remission with the current management of recurrence (intensive plasmapheresis/immunosuppression, including rituximab), and other promising agents are being evaluated. Therefore, a pathologic diagnosis of FSGS itself should not cause postponement of allograft kidney transplantation. For patients with a high risk of recurrence who presented with classical symptoms of NS, that is, severe edema, proteinuria, and hypoalbuminemia, close monitoring of proteinuria is necessary, followed by immediate, intensive treatment for recurrence.
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Miyake N, Tsukaguchi H, Koshimizu E, Shono A, Matsunaga S, Shiina M, Mimura Y, Imamura S, Hirose T, Okudela K, Nozu K, Akioka Y, Hattori M, Yoshikawa N, Kitamura A, Cheong HI, Kagami S, Yamashita M, Fujita A, Miyatake S, Tsurusaki Y, Nakashima M, Saitsu H, Ohashi K, Imamoto N, Ryo A, Ogata K, Iijima K, Matsumoto N. Biallelic Mutations in Nuclear Pore Complex Subunit NUP107 Cause Early-Childhood-Onset Steroid-Resistant Nephrotic Syndrome. Am J Hum Genet 2015; 97:555-66. [PMID: 26411495 DOI: 10.1016/j.ajhg.2015.08.013] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Accepted: 08/28/2015] [Indexed: 12/19/2022] Open
Abstract
The nuclear pore complex (NPC) is a huge protein complex embedded in the nuclear envelope. It has central functions in nucleocytoplasmic transport, nuclear framework, and gene regulation. Nucleoporin 107 kDa (NUP107) is a component of the NPC central scaffold and is an essential protein in all eukaryotic cells. Here, we report on biallelic NUP107 mutations in nine affected individuals who are from five unrelated families and show early-onset steroid-resistant nephrotic syndrome (SRNS). These individuals have pathologically focal segmental glomerulosclerosis, a condition that leads to end-stage renal disease with high frequency. NUP107 is ubiquitously expressed, including in glomerular podocytes. Three of four NUP107 mutations detected in the affected individuals hamper NUP107 binding to NUP133 (nucleoporin 133 kDa) and NUP107 incorporation into NPCs in vitro. Zebrafish with nup107 knockdown generated by morpholino oligonucleotides displayed hypoplastic glomerulus structures and abnormal podocyte foot processes, thereby mimicking the pathological changes seen in the kidneys of the SRNS individuals with NUP107 mutations. Considering the unique properties of the podocyte (highly differentiated foot-process architecture and slit membrane and the inability to regenerate), we propose a "podocyte-injury model" as the pathomechanism for SRNS due to biallelic NUP107 mutations.
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Affiliation(s)
- Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Hiroyasu Tsukaguchi
- Second Department of Internal Medicine, Kansai Medical University, Osaka 570-8507, Japan.
| | - Eriko Koshimizu
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Akemi Shono
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Satoko Matsunaga
- Department of Microbiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Masaaki Shiina
- Department of Biochemistry, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | | | - Shintaro Imamura
- National Research Institute of Fisheries Science, Yokohama 236-8648, Japan
| | - Tomonori Hirose
- Department of Molecular Biology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Koji Okudela
- Department of Pathology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Yuko Akioka
- Department of Pediatric Nephrology, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Motoshi Hattori
- Department of Pediatric Nephrology, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Norishige Yoshikawa
- Center for Clinical Research and Development, National Center for Child Health and Development, Tokyo 157-8535, Japan
| | - Akiko Kitamura
- Department of Immunology & Parasitology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Hae Il Cheong
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul 03080, Korea; Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul 03080, Korea; Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Shoji Kagami
- Department of Pediatrics, University of Tokushima Graduate School, Tokushima 770-8503, Japan
| | - Michiaki Yamashita
- National Research Institute of Fisheries Science, Yokohama 236-8648, Japan
| | - Atsushi Fujita
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Satoko Miyatake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Yoshinori Tsurusaki
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Mitsuko Nakashima
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Hirotomo Saitsu
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Kenichi Ohashi
- Department of Pathology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Naoko Imamoto
- Cellular Dynamics Laboratory, RIKEN, Wako 351-0198, Japan
| | - Akihide Ryo
- Department of Microbiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Kazuhiro Ogata
- Department of Biochemistry, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan.
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Hameed A, Mir A, Nasir M, Ajmal M. Bioinformatics evaluation of NPHS2 deletion mutation associated with congenital nephrotic syndrome in a consanguineous Pakistani family. Clin Genet 2014; 87:599-601. [PMID: 25143137 DOI: 10.1111/cge.12486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 08/18/2014] [Accepted: 08/18/2014] [Indexed: 11/30/2022]
Affiliation(s)
- A Hameed
- Institute of Biomedical and Genetic Engineering (IBGE), Islamabad, Pakistan
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Jaffer A, Unnisa W, Raju DSB, Jahan P. NPHS2mutation analysis and primary nephrotic syndrome in southern Indians. Nephrology (Carlton) 2014; 19:398-403. [DOI: 10.1111/nep.12241] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2014] [Indexed: 11/29/2022]
Affiliation(s)
- Asra Jaffer
- Department of Genetics; Osmania University; Hyderabad Andhra Pradesh India
| | - Wali Unnisa
- Department of Genetics; Osmania University; Hyderabad Andhra Pradesh India
| | - DSB Raju
- Department of Nephrology; Nizam's Institute of Medical Sciences; Hyderabad Andhra Pradesh India
| | - Parveen Jahan
- Department of Genetics; Osmania University; Hyderabad Andhra Pradesh India
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Lee SE, Min SI, Kim YS, Ha J, Ha IS, Cheong HI, Kim SJ, Choi Y, Kang HG. Recurrence of idiopathic focal segmental glomerulosclerosis after kidney transplantation: experience of a Korean tertiary center. Pediatr Transplant 2014; 18:369-76. [PMID: 24802343 DOI: 10.1111/petr.12257] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/24/2014] [Indexed: 11/29/2022]
Abstract
FSGS is the second most common cause of idiopathic NS in children. It often progresses to ESRD and commonly recurs after KT. To investigate the risk factors and the prognosis of recurrence in pediatric idiopathic FSGS in Korea, retrospective review of 43 KT in 38 children with idiopathic FSGS of last two decades was conducted. The patients presented at the median age of 5.1 yr (range 1.1-13.8 yr) and received KT 5.7 yr later (range 1.3-17.6 yr). FSGS recurred in 20 allografts immediately after transplantation, only in those who presented with NS but not in those who presented with AUA. The risk factors for recurrence were age of onset >5 yr and progression to ESRD within six yr but not sooner than 18 months. CR was achieved in 13 patients with FSGS recurrence and sustained in nine without subsequent relapse over a median of six and a half yr (0.6-20.7 yr). Pediatric idiopathic FSGS presenting with NS recurred in more than half of patients after transplantation. Interestingly, more rapid progression within less than 18 months did not predict recurrence. To identify high-risk patients of recurrence, an international cooperative study would be necessary.
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Affiliation(s)
- Se Eun Lee
- Department of Pediatrics, Seoul National University College of Medicine and Research Center for Rare Diseases, Seoul, Korea
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Piscione TD, Licht C. Genetics of proteinuria: an overview of gene mutations associated with nonsyndromic proteinuric glomerulopathies. Adv Chronic Kidney Dis 2011; 18:273-89. [PMID: 21782134 DOI: 10.1053/j.ackd.2011.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2011] [Revised: 06/02/2011] [Accepted: 06/16/2011] [Indexed: 02/08/2023]
Abstract
Heritable causes of proteinuria are rare and account for a relatively small proportion of all cases of proteinuria affecting children and adults. Yet, significant contributions to understanding the mechanistic basis for proteinuria have been made through genetic and molecular analyses of a small group of syndromic and nonsyndromic proteinuric disorders which are caused by mutations encoding structural components of the glomerular filtration barrier. Technological advances in genomic analyses and improved accessibility to mutational screening at clinically approved laboratories have facilitated diagnosis of proteinuria in the clinical setting. From a clinical standpoint, it may be argued that a genetic diagnosis mitigates exposure to potentially ineffective and harmful treatments in instances where a clear genotype-phenotype correlation exists between a specific gene mutation and treatment nonresponsiveness. However, cautious interpretation of risk may be necessitated in cases with phenotypic heterogeneity (eg, variability in clinical or histological presentation). This review summarizes gene mutations which are known to be associated with proteinuric glomerulopathies in children and adults.
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Gubler MC. Nephrotic syndrome: Genetic testing in steroid-resistant nephrotic syndrome. Nat Rev Nephrol 2011; 7:430-1. [PMID: 21691316 DOI: 10.1038/nrneph.2011.75] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Aya K, Shimizu J, Ohtomo Y, Satomura K, Suzuki H, Yan K, Sado Y, Morishima T, Tanaka H. NPHS1 gene mutation in Japanese patients with congenital nephrotic syndrome. Nephrol Dial Transplant 2009; 24:2411-4. [PMID: 19321760 DOI: 10.1093/ndt/gfp122] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND AND METHODS The NPHS1gene was analysed in different five Japanese patients with congenital nephrotic syndrome (CNS) from the patients in a previous report (Sako M, Nakanishi K, Obana M et al. Analysis of NPHS1, NPHS2, ACTN4, and WT1 in Japanese patients with congenital nephrotic syndrome. Kidney Int 2005; 67: 1248-1255) that suggested that the mutation of NPHS1 was not a major cause of CNS in Japanese patients. Genomic DNA was extracted from leukocytes, and all exons and exon-intron boundaries were analysed for NPHS1 using polymerase chain reaction and direct sequencing. RESULTS AND CONCLUSIONS Compound heterozygous mutations of NPHS1 were found in four patients and homozygous mutations in one patient. Interestingly, three patients out of five had the same mutation in NPHS1: nt2515(delC). Parents who had this mutation heterozygously were from neighbouring prefectures. Two among five patients in this research and one in the previous report (Kidney Int 2005; 67:1248-1255) had the same mutation: 736G > T in exon 7. All mutations including these two mutations except for one have never been reported outside of Japan yet.
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Affiliation(s)
- Kunihiko Aya
- Department of Pediatrics, Okayama University Medical School, National Okayama Medical Center,Okayama, Okayama, Japan.
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12
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Chernin G, Heeringa SF, Gbadegesin R, Liu J, Hinkes BG, Vlangos CN, Vega-Warner V, Hildebrandt F. Low prevalence of NPHS2 mutations in African American children with steroid-resistant nephrotic syndrome. Pediatr Nephrol 2008; 23:1455-60. [PMID: 18543005 PMCID: PMC5495478 DOI: 10.1007/s00467-008-0861-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Revised: 04/04/2008] [Accepted: 04/09/2008] [Indexed: 01/15/2023]
Abstract
In African American (AA) children, focal segmental glomerulosclerosis (FSGS) is the leading cause of nephrotic syndrome (NS). It has been shown that AA children suffer from FSGS and steroid-resistant nephrotic syndrome (SRNS) at a higher frequency and with a more severe renal outcome in comparison with Caucasian children. Previous mutation analysis of large cohorts revealed that a high percentage of childhood SRNS is monogenic and that mutations in podocin (NPHS2) and Wilms' tumor gene 1 (WT1) account for approximately 30% of SRNS in children. To test whether AA children with SRNS have a similar or a higher mutation rate, we performed mutation analysis of NPHS2 and WT1 in a cohort of AA children with SRNS. Direct sequencing was carried out for all exons of NPHS2 and for exons 8 and 9 of WT1. We ascertained 18 children of AA descent in whom renal biopsy findings showed FSGS in 13 patients (72%) and minimal-change disease in five patients (28%). In both NPHS2 and WT1, no disease-causing mutations were detected. Our data strongly suggest that in AA children with SRNS, the frequency of NPHS2 mutations is much lower than in large cohorts of pediatric SRNS patients in the general population. Knowledge of mutation rate of NPHS2 in different populations of SRNS patients facilitates the physician in planning a suitable genetic screening strategy for patients.
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Affiliation(s)
- Gil Chernin
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
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Furue T, Hattori M, Tsukaguchi H, Kitamura A, Oomori T, Ogino D, Nakakura H, Ashida A, Miura K, Hisano M, Takahashi K, Chikamoto H, Akioka Y, Sakano T. Clinical features and mutational survey of NPHS2 (podocin) in Japanese children with focal segmental glomerulosclerosis who underwent renal transplantation. Pediatr Transplant 2008; 12:341-6. [PMID: 18208440 DOI: 10.1111/j.1399-3046.2007.00752.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recurrent FSGS is a major challenge in the field of nephrology. To clarify the role of NPHS2 defects in the pathogenesis of FSGS recurrence, we sequenced all eight exons of NPHS2 in 11 Japanese pediatric FSGS patients with or without post-transplant recurrence. All patients had biopsy-proven primary FSGS, had no family history of renal diseases or consanguinity, were steroid-resistant, and received living-related renal transplantation. The mean age at onset was 5.0 +/- 3.1 yr and mean age at renal transplantation was 10.4 +/- 4.1 yr. Mutational analysis of NPHS2 was performed using polymerase chain reaction and direct sequencing. We found a synonymous T/C polymorphism at alanine 318 (GCC to GCT) in seven of 11 patients but no other causative NPHS2 mutations. FSGS recurred immediately after transplant in seven patients, while the remaining four patients had no recurrence for 3.2-5.8 yr. There were no differences between recurrent and non-recurrent patients in the onset age and the interval from onset to ESRD. In conclusion, we detected no causative NPHS2 mutations in Japanese pediatric FSGS patients with or without post-transplant recurrence. Further studies on the involvement of other genes are required to better understand recurrent FSGS.
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Affiliation(s)
- Takeki Furue
- Department of Pediatric Nephrology, Tokyo Women's Medical University, School of Medicine, Tokyo, Japan
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Berdeli A, Mir S, Yavascan O, Serdaroglu E, Bak M, Aksu N, Oner A, Anarat A, Donmez O, Yildiz N, Sever L, Tabel Y, Dusunsel R, Sonmez F, Cakar N. NPHS2 (podicin) mutations in Turkish children with idiopathic nephrotic syndrome. Pediatr Nephrol 2007; 22:2031-40. [PMID: 17899208 DOI: 10.1007/s00467-007-0595-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Revised: 07/10/2007] [Accepted: 07/13/2007] [Indexed: 10/22/2022]
Abstract
The podocin (NPHS2) gene encodes podocin protein, which has an important role in glomerular ultrafiltration and controlling slit membrane permeability. The detection of an NPHS2 mutation affects the treatment plan for children with nephritic syndrome (NS). The frequency and spectrum of podocin mutations in the Turkish population have remained largely unknown. The aim of this study was to screen for podocin mutations in Turkish patients with steroid-resistant NS (SRNS) and to compare it with other published series. There were 295 children with SRNS, originating from Turkey, included in this study. Forty-one patients (13.8%) had familial NS and 254 patients (86.2%) had sporadic NS. Mutation analysis was performed in all eight exons of the NPHS2 gene with the direct DNA sequencing method. There were 53 different pathogenetic NPHS2 mutations detected, including 37 novel mutations. The mutation detection rate was 24.7% for all patients, 29.2% for familial, and 24% for sporadic SRNS. The most common mutated exon was exon 5 (52 allele). The presence of mutations in exon 4 was found to increase the risk of end-stage renal disease (ESRD). Among patients with mutations, the rates of renal failure and/or ESRD (26%) were significantly higher than in those without mutations (12.6%). The mean time of progression to renal failure and ESRD in patients with mutations (1.8 +/- 2.5 years) was significantly shorter than in patients without mutations (3.7 +/- 4.0 years). Additionally, in patients with heterozygote mutations, fewer cases (13.6%) progressed to renal failure and/or ESRD than in with patients who had homozygote/compound heterozygote mutations (31.3%). In conclusion, podocin mutations are responsible for some of both familial and sporadic SRNS cases in Turkey. The mutations in this gene should be searched for in every child after presentation with the first episode of NS.
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Affiliation(s)
- Afig Berdeli
- Department of Molecular Genetics, Ege University Faculty of Medicine, Izmir, Turkey.
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