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Caparali EB, De Gregorio V, Barua M. Genetic Causes of Nephrotic Syndrome and Focal and Segmental Glomerulosclerosis. ADVANCES IN KIDNEY DISEASE AND HEALTH 2024; 31:309-316. [PMID: 39084756 DOI: 10.1053/j.akdh.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 03/29/2024] [Accepted: 04/01/2024] [Indexed: 08/02/2024]
Abstract
The field of nephrology has a long-standing interest in deciphering the genetic basis of nephrotic syndrome (NS), motivated by the mechanistic insights it provides in chronic kidney disease. The initial era of genetic studies solidified NS and the focal segmental glomerulosclerosis lesion as podocyte disorders. The likelihood of identifying a single gene (called monogenic) cause is higher if certain factors are present such as positive family history. Obtaining a monogenic diagnosis enables reproductive counseling and screening of family members. Now, with a new era of genomic studies facilitated by technological advances and the emergence of large genetically characterized cohorts, more insights are apparent. This includes the phenotypic breadth associated with disease genes, as evidenced in Alport syndrome and congenital NS of the Finnish type. Moreover, the underlying genetic architecture is more complex than previously appreciated, as shown by genome-wide association studies, suggesting that variants in multiple genes collectively influence risk. Achieving molecularly informed diagnoses also holds substantial potential for personalizing medicine, including the development of targeted therapeutics. Illustrative examples include coenzyme Q10 for ADCK4-associated NS and inaxaplin, a small molecule that inhibits apolipoprotein L1 channel activity, though larger studies are required to confirm benefit.
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Affiliation(s)
- Emine Bilge Caparali
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada; Division of Nephrology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Vanessa De Gregorio
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada; Division of Nephrology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Moumita Barua
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada; Division of Nephrology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.
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2
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Gharesouran J, Hosseinzadeh H, Ghergherechi R, Shiva S, Taheri M, Liehr T, Rezazadeh M. Loss of helicase C-terminal domain of SMARCAL1 protein associated with severe Schimke immuno-osseous dysplasia. Pathol Res Pract 2024; 254:155092. [PMID: 38218042 DOI: 10.1016/j.prp.2024.155092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 12/28/2023] [Accepted: 01/01/2024] [Indexed: 01/15/2024]
Abstract
Schimke immuno-osseous dysplasia (SIOD) is a rare multi-system condition caused by biallelic loss-of-function mutations in the SMARCAL1 gene. This disorder is characterized by disproportionate growth failure, T-cell deficiency, and renal dysfunction. Pathogenic variants in the SMARCAL1 gene have been reported in only approximately half of SIOD-affected individuals. Among these alterations, nonsense and frameshift mutations generally lead to a severe phenotype with early onset. In this study, we identified novel mutations in an Iranian patient with SIOD. A 4-year-old girl with developmental delay and facial dysmorphism was referred to our center for molecular diagnosis. We applied whole-exome and Sanger sequencing for co-segregation analysis. Subsequently, bioinformatic analysis was performed to assess the pathogenic effects of the variants and their post-transcriptional effects. We discovered two novel mutations (c.2281delT and c.2283delA) in exon 15 of the SMARCAL1 gene, resulting in a truncated protein with a loss of 193 amino acids (p.S761Rfs*1). Variant effect predictors indicated that these variants are pathogenic, and multi-sequence alignments revealed high conservation of this region among different species. Given that our patient exhibited severe a phenotype and passed away soon after receiving a definitive molecular diagnosis, we propose that the loss of the helicase C-terminal domain in the deleted part of SMARCAL1 may lead to the severe form of SIOD. Besides, the combination of growth retardation and bone abnormalities also plays a crucial role in the early diagnosis of the disease.
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Affiliation(s)
- Jalal Gharesouran
- Department of Medical Genetics, GMG center, Tabriz University of Medical Sciences, Tabriz, Iran; Division of Medical Genetics, School of Medicine, Children's Medical Research and Training Hospital, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hassan Hosseinzadeh
- Department of Medical Genetics, GMG center, Tabriz University of Medical Sciences, Tabriz, Iran; Division of Medical Genetics, School of Medicine, Children's Medical Research and Training Hospital, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Robabeh Ghergherechi
- Department of Pediatrics, School of Medicine, Children's Medical Research and Training Hospital, Tabriz University of Medical Sciences, Tabriz, Iran; Pediatric Health Research Center, Tabriz University of Medical Sciences, Tabriz, East Azerbaijan,Iran
| | - Siamak Shiva
- Department of Pediatrics, School of Medicine, Children's Medical Research and Training Hospital, Tabriz University of Medical Sciences, Tabriz, Iran; Pediatric Health Research Center, Tabriz University of Medical Sciences, Tabriz, East Azerbaijan,Iran
| | - Mohammad Taheri
- Institute of Human Genetics, Jena University Hospital, Jena, Germany.
| | - Thomas Liehr
- Institute of Human Genetics, Jena University Hospital, Jena, Germany.
| | - Maryam Rezazadeh
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
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3
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Orozco RAP, Padilla-Guzmán A, Forero-Delgadillo JM, Jiménez VAO, Pachajoa H, Parra NJV, Restrepo JM. Schimke immuno-osseous dysplasia. A case report in Colombia. Mol Genet Metab Rep 2023; 37:100995. [PMID: 37662493 PMCID: PMC10472290 DOI: 10.1016/j.ymgmr.2023.100995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/28/2023] [Accepted: 07/29/2023] [Indexed: 09/05/2023] Open
Abstract
Background Schimke immune-osseous dysplasia (SIOD) is an ultra-rare multisystemic, monogenic, and autosomal recessive inherited disease caused by biallelic mutations in the SMARCAL1 gene. Approximately 100 cases have been reported worldwide. The disease is characterized by skeletal, renal, and immunological abnormalities. Case description This is a 6-year-old female patient who debuted with nephrotic syndrome at five years of age, with a switch to corticosteroid resistance and poor response to immunosuppressive treatment received. The patient was admitted and referred to our institution due to convulsive status. During her hospitalization, thrombosis was found in the left renal vein, and a renal biopsy report of Collapsing Focal and Segmental Glomerulosclerosis (FSGS) was obtained. The patient had multiple infections during hospitalization, with T lymphocyte lymphopenia and severe IgG hypogammaglobulinemia. Additionally, given dysmorphic facies, delayed weight-height development, and spondyloepiphyseal dysplasia, exome sequencing was performed, finding an homozygous pathogenic variant c.1933C > T p.Arg645Cys in SMARCAL1, compatible with the diagnosis of SIOD. Discussion We present the case of a patient that exhibited a severe phenotype of the disease, with skeletal, renal, severe combined immunological compromise and cerebrovascular involvement during follow-up, and the available proposed mechanisms of the disease focused on the clinical manifestations of this patient. It is the first case of SIOD reported in Colombia and the first comprehensive characterization reported in the literature of a patient with homozygosity of the known variant c.1933C > T p.Arg645Cys. Conclusion A severe phenotype of the disease with cerebrovascular involvement by homozygosity of the known variant c.1933C > T p.Arg645Cys in the SMARCAL1 gene can be expected.
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Affiliation(s)
| | | | - Jessica María Forero-Delgadillo
- Servicio de nefrología pediátrica, Departamento de salud maternoinfantil, Fundación Valle del Lili, Cali, Colombia
- Facultad de ciencias de la salud, Universidad Icesi, Cali, Colombia
| | - Vanessa Amparo Ochoa Jiménez
- Servicio de nefrología pediátrica, Departamento de salud maternoinfantil, Fundación Valle del Lili, Cali, Colombia
- Facultad de ciencias de la salud, Universidad Icesi, Cali, Colombia
| | - Harry Pachajoa
- Servicio de genética, Fundación Valle del Lili, Cali, Colombia
- Facultad de ciencias de la salud, Universidad Icesi, Cali, Colombia
- Centro de Investigaciones en Anomalías Congénitas y Enfermedades Raras (CIACER), Universidad Icesi, Cali, Colombia
| | | | - Jaime M. Restrepo
- Servicio de nefrología pediátrica, Departamento de salud maternoinfantil, Fundación Valle del Lili, Cali, Colombia
- Facultad de ciencias de la salud, Universidad Icesi, Cali, Colombia
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Mo X, Chen X, Zeng H, Zheng W, Ieong C, Li H, Huang Q, Xu Z, Yang J, Liang Q, Liang H, Gao X, Huang M, Li J. Tacrolimus in the treatment of childhood nephrotic syndrome: Machine learning detects novel biomarkers and predicts efficacy. Pharmacotherapy 2023; 43:43-52. [PMID: 36521865 DOI: 10.1002/phar.2749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/10/2022] [Accepted: 11/10/2022] [Indexed: 12/23/2022]
Abstract
STUDY OBJECTIVE The pharmacokinetics and pharmacodynamics of tacrolimus (TAC) vary greatly among individuals, hindering its precise utilization. Moreover, effective models for the early prediction of TAC efficacy in patients with nephrotic syndrome (NS) are lacking. We aimed to identify key factors affecting TAC efficacy and develop efficacy prediction models for childhood NS using machine learning algorithms. DESIGN This was an observational cohort study of patients with pediatric refractory NS. SETTING Guangzhou Women and Children's Medical Center between June 2013 and December 2018. PATIENTS 203 patients with pediatric refractory NS were used for model generation and 35 patients were used for model validation. INTERVENTION All patients regularly received double immunosuppressive therapy comprising TAC and low-dose prednisone or methylprednisolone. In this observational cohort study of 203 pediatric patients with refractory NS, clinical and genetic variables, including single-nucleotide polymorphism (SNPs), were identified. TAC efficacy was evaluated 3 months after administration according to two different evaluation criteria: response or non-response (Group 1) and complete remission, partial remission, or non-remission (Group 2). MEASUREMENTS Logistic regression, extremely random trees, gradient boosting decision trees, random forest, and extreme gradient boosting algorithms were used to develop and validate the models. Prediction models were validated among a cohort of 35 patients with NS. MAIN RESULTS The random forest models performed best in both groups, and the area under the receiver operating characteristics curve of these two models was 80.7% (Group 1) and 80.3% (Group 2). These prediction models included urine erythrocyte count before administration, steroid types, and eight SNPs (ITGB4 rs2290460, TRPC6 rs3824934, CTGF rs9399005, IL13 rs20541, NFKBIA rs8904, NFKBIA rs8016947, MAP3K11 rs7946115, and SMARCAL1 rs11886806). CONCLUSIONS Two pre-administration models with good predictive performance for TAC response of patients with NS were developed and validated using machine learning algorithms. These accurate models could assist clinicians in predicting TAC efficacy in pediatric patients with NS before utilization to avoid treatment failure or adverse effects.
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Affiliation(s)
- Xiaolan Mo
- Department of Pharmacy, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China.,Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Xiujuan Chen
- Department of Medical Big Data Center, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Huasong Zeng
- Division of Nephrology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Wei Zheng
- Department of Pharmacy, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Chifong Ieong
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Huixian Li
- Department of Medical Big Data Center, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Qiongbo Huang
- Department of Pharmacy, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Zichuan Xu
- Division of Nephrology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Jinlian Yang
- Department of Pharmacy, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Qianying Liang
- Department of Pharmacy, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Huiying Liang
- Department of Medical Big Data Center, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xia Gao
- Division of Nephrology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Min Huang
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jiali Li
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
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Marin AV, Jiménez-Reinoso A, Mazariegos MS, Román-Ortiz E, Regueiro JR. T-cell receptor signaling in Schimke immuno-osseous dysplasia is SMARCAL1-independent. Front Immunol 2022; 13:979722. [PMID: 36330520 PMCID: PMC9623027 DOI: 10.3389/fimmu.2022.979722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 09/22/2022] [Indexed: 11/26/2022] Open
Abstract
Schimke immuno-osseous dysplasia (SIOD) caused by mutations in SMARCAL1 is an ultra-rare disease characterized by specific facial features, skeletal dysplasia, and steroid-resistant nephrotic syndrome, which often leads to kidney failure and requires transplantation. Cellular (T-cell) deficiency, lymphopenia, and infections have been frequently reported, but whether they are due to T-cell-intrinsic defects in T-cell receptor (TCR) signaling associated with SMARCAL1 deficiency or to T-cell-extrinsic effects such as the impaired proliferation of hematopoietic precursors or T-cell-specific immunosuppression after renal transplantation remains unknown. We have explored the effects of SMARCAL1 deficiency on T-cell receptor signaling in primary and immortalized T cells from a 9-year-old SIOD patient under immunosuppression treatment when compared to healthy donors. Immortalized T cells recapitulated the SMARCAL1 deficiency of the patient, as judged by their impaired response to gamma irradiation. The results indicated that TCR-mediated signaling was normal in SIOD-derived immortalized T cells but strongly impaired in the primary T cells of the patient, although rescued with TCR-independent stimuli such as PMA + ionomycin, suggesting that SIOD-associated T-cell signaling is not intrinsically defective but rather the result of the impaired proliferation of hematopoietic precursors or of T-cell-specific immunosuppression. The lack of early thymic emigrants in our patients may support the former hypothesis.
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Affiliation(s)
- Ana V. Marin
- Department of Immunology, Ophthalmology and Ear, Nose and Throat (ENT), Complutense University School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - Anaïs Jiménez-Reinoso
- Department of Immunology, Ophthalmology and Ear, Nose and Throat (ENT), Complutense University School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - Marina S. Mazariegos
- Department of Immunology, Ophthalmology and Ear, Nose and Throat (ENT), Complutense University School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - Elena Román-Ortiz
- Pediatric Nephrology, Hospital Universitari i Politècnic la Fe, Valencia, Spain
| | - José R. Regueiro
- Department of Immunology, Ophthalmology and Ear, Nose and Throat (ENT), Complutense University School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
- *Correspondence: José R. Regueiro,
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6
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Wang L, Li J, Wu G, Kong X. A novel compound heterozygous variant in SMARCAL1 leading to mild Schimke immune-osseous dysplasia identified using whole-exome sequencing. J Int Med Res 2021; 49:3000605211010644. [PMID: 33900868 PMCID: PMC8829751 DOI: 10.1177/03000605211010644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/24/2021] [Indexed: 11/16/2022] Open
Abstract
Schimke immuno-osseous dysplasia (SIOD) is a rare autosomal recessive inherited disorder that is caused by the SMARCAL1 mutation. The phenotype can vary from mild to severe on the basis of the patient's age at onset. Herein, we report the case of a 14-year-old Chinese boy who presented with short stature, focal segmental glomerulosclerosis (FSGS), and facial dysmorphism. Genetic analysis revealed two compound heterozygous missense mutations, including a well-known mutation (c.1933C>T, p.R645C) and a novel mutation (c.2479G>A, p.V827M) in the SMARCAL1 gene, which were inherited from his parents. In silico analyses showed that the c.2479G>A (p.V827M) variant affects a highly conserved residue within the ATPase catalytic domain. Finally, we established the diagnosis of mild SIOD and treated the patient with diuretics and angiotensin receptor blockers. This report expands the mutational spectrum of SMARCAL1 and reinforces the importance of a detailed clinical evaluation, molecular detection, and appropriate genetic counseling.
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Affiliation(s)
- Li Wang
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Erqi District, 1 Jianshe East Road, Zhengzhou, P. R. China
- Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, 1 Jianshe East Road, Zhengzhou, P. R. China
| | - Jingjing Li
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Erqi District, 1 Jianshe East Road, Zhengzhou, P. R. China
- Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, 1 Jianshe East Road, Zhengzhou, P. R. China
| | - Ge Wu
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Erqi District, 1 Jianshe East Road, Zhengzhou, P. R. China
- Research Institute of Nephrology, Zhengzhou University, Erqi District, 1 Jianshe East Road, Zhengzhou, P. R. China
| | - Xiangdong Kong
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Erqi District, 1 Jianshe East Road, Zhengzhou, P. R. China
- Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, 1 Jianshe East Road, Zhengzhou, P. R. China
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Grohs J, Rebling RM, Froede K, Hmeidi K, Pavičić L, Gellermann J, Müller D, Querfeld U, Haffner D, Živičnjak M. Determinants of growth after kidney transplantation in prepubertal children. Pediatr Nephrol 2021; 36:1871-1880. [PMID: 33620573 PMCID: PMC8172393 DOI: 10.1007/s00467-021-04922-2] [Citation(s) in RCA: 2] [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: 09/16/2020] [Revised: 11/23/2020] [Accepted: 01/05/2021] [Indexed: 01/23/2023]
Abstract
BACKGROUND Short stature is a frequent complication after pediatric kidney transplantation (KT). Whether the type of transplantation and prior treatment with recombinant human growth hormone (GH) affects post-transplant growth, is unclear. METHODS Body height, leg length, sitting height, and sitting height index (as a measure of body proportions) were prospectively investigated in 148 prepubertal patients enrolled in the CKD Growth and Development study with a median follow-up of 5.0 years. We used linear mixed-effects models to identify predictors for body dimensions. RESULTS Pre-transplant Z scores for height (- 2.18), sitting height (- 1.37), and leg length (- 2.30) were reduced, and sitting height index (1.59) was increased compared to healthy children, indicating disproportionate short stature. Catch-up growth in children aged less than 4 years was mainly due to stimulated trunk length, and in older children to improved leg length, resulting in normalization of body height and proportions before puberty in the majority of patients. Use of GH in the pre-transplant period, congenital CKD, birth parameters, parental height, time after KT, steroid exposure, and transplant function were significantly associated with growth outcome. Although, unadjusted growth data suggested superior post-transplant growth after (pre-emptive) living donor KT, this was no longer true after adjusting for the abovementioned confounders. CONCLUSIONS Catch-up growth after KT is mainly due to stimulated trunk growth in young children (< 4 years) and improved leg growth in older children. Beside transplant function, steroid exposure and use of GH in the pre-transplant period are the main potentially modifiable factors associated with better growth outcome.
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Affiliation(s)
- Julia Grohs
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children’s Hospital, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Rainer-Maria Rebling
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children’s Hospital, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Kerstin Froede
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children’s Hospital, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Kristin Hmeidi
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children’s Hospital, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany ,Department of Orthopedic Surgery, Vivantes Auguste-Viktoria-Hospital, Rubensstr. 125, 12157 Berlin, Germany
| | | | - Jutta Gellermann
- Department Department of Pediatrics, Division of Gastroenterology, Nephrology and Metabolic Diseases, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augstenburger Platz 1, 13353 Berlin, Germany
| | - Dominik Müller
- Department Department of Pediatrics, Division of Gastroenterology, Nephrology and Metabolic Diseases, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augstenburger Platz 1, 13353 Berlin, Germany
| | - Uwe Querfeld
- Department Department of Pediatrics, Division of Gastroenterology, Nephrology and Metabolic Diseases, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augstenburger Platz 1, 13353 Berlin, Germany
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children’s Hospital, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Miroslav Živičnjak
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children's Hospital, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
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Jin J, Wu K, Liu Z, Chen X, Jiang S, Wang Z, Li W. Whole Exome Sequencing Identified a Novel Biallelic SMARCAL1 Mutation in the Extremely Rare Disease SIOD. Front Genet 2019; 10:565. [PMID: 31275356 PMCID: PMC6591458 DOI: 10.3389/fgene.2019.00565] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 05/29/2019] [Indexed: 01/06/2023] Open
Abstract
Schimke immuno-osseous dysplasia (SIOD) is an extremely rare autosomal recessive pleiotropic disease. Although biallelic mutations in SMARCAL1 gene have been reported to be the genetic etiology of SIOD, its molecular diagnosis has been challenging in a relatively proportion of cases due to the extreme rarity. Here, we made a definitive SIOD diagnosis of a 5-year-old girl with an extremely mild phenotype by applying whole exome sequencing (WES). As a result, a novel maternal mutation (c.2141+5G > A) confirmed to create a novel splice donor site combined with a known paternal mutation (c.1933C > T; p.Arg645Cys) were detected. In addition, previous reported SIOD cases showed excessive enrichment for mutations in the helicase ATP-binding and C-terminal domains of SMARCAL1. Similarly, the novel mutation we identified caused a mutant protein truncated in the SMARCAL1 C-terminus. Interestingly, based on the phenotypic profile, compared to reported cases, the patient in our study exhibited milder symptoms with renal dysfunctions limited to asymptomatic proteinuria, but no neurological signs or recurrent infections. Moreover, we identified 73 SMARCAL1-interacting genes, which formed a significant interconnected interaction network with roles in disease-related pathways such as double-strand break repair via homologous recombination, DNA repair, and replication fork processing. Notably, the top 15 SMARCAL1-interacting genes all showed a similar renal temporal expression pattern. Altogether, to our knowledge, the case in this study is the first case diagnosed originally based on a genetic test via WES rather than a characteristic phenotype. The identification of the novel allelic mutation (c.2141+5G > A) extends the phenotypic spectrum of SMARCAL1 mutations and the following bioinformatics analysis presents additional genetic evidence to illustrate the role of SMARCAL1 in SIOD.
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Affiliation(s)
- Jing Jin
- School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Keke Wu
- Wenzhou Center for Disease Control and Prevention, Wenzhou, China
| | - Zhenwei Liu
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
| | - Xiaomin Chen
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China.,Center of Scientific Research, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Shan Jiang
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
| | - Zhen Wang
- School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,Research Center of Blood Transfusion Medicine, Education Ministry Key Laboratory of Laboratory Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Weixing Li
- School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,Zhejiang Center for Clinical Laboratory, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
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9
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Yuruk Yildirim Z, Ozkan M, Yilmaz A, Kayserili H, Pehlivanoglu C, Emre S, Nayir A. An unusual cause of nephrotic syndrome: Answers. Pediatr Nephrol 2019; 34:819-821. [PMID: 30406368 DOI: 10.1007/s00467-018-4115-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 09/27/2018] [Accepted: 10/05/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Zeynep Yuruk Yildirim
- Istanbul Faculty of Medicine, Pediatric Nephrology Department, Istanbul University, Istanbul, Turkey.
| | - Melis Ozkan
- Istanbul Faculty of Medicine, Department of Pediatrics, Istanbul University, Istanbul, Turkey
| | - Alev Yilmaz
- Istanbul Faculty of Medicine, Pediatric Nephrology Department, Istanbul University, Istanbul, Turkey
| | - Hülya Kayserili
- Istanbul Faculty of Medicine, Medical Genetics Department, Istanbul University, Istanbul, Turkey.,Medical Genetics Department & Genetic Diagnosis Center, Koç University School of Medicine, Istanbul, Turkey
| | - Cemile Pehlivanoglu
- Istanbul Faculty of Medicine, Pediatric Nephrology Department, Istanbul University, Istanbul, Turkey
| | - Sevinc Emre
- Istanbul Faculty of Medicine, Pediatric Nephrology Department, Istanbul University, Istanbul, Turkey
| | - Ahmet Nayir
- Istanbul Faculty of Medicine, Pediatric Nephrology Department, Istanbul University, Istanbul, Turkey
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10
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A novel compound heterozygous mutation of the SMARCAL1 gene leading to mild Schimke immune-osseous dysplasia: a case report. BMC Pediatr 2017; 17:217. [PMID: 29282041 PMCID: PMC5745888 DOI: 10.1186/s12887-017-0968-8] [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: 07/20/2016] [Accepted: 12/12/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Schimke immune-osseous dysplasia (SIOD, OMIM 242900) is characterized by spondyloepiphyseal dysplasia, T-cell deficiency, renal dysfunction and special facial features. SMARCAL1 gene mutations are determined in approximately 50% of patients diagnosed with SIOD. CASE PRESENTATION The case presented here is that of a 6-year-old boy who was born at 33 weeks to healthy, non-consanguineous Chinese parents. He presented with short stature (95 cm; <3rd percentile) and proteinuria. Initially suspected of having IgM nephropathy, the patient was finally diagnosed with mild Schimke immune-osseous dysplasia. One novel mutation (p.R817H) and one well-known mutation (p.R645C) was identified in the SMARCAL1 gene. CONCLUSION This report describes a clinical and genetic diagnostic model of mild SIOD. It also highlights the importance of molecular testing or clinical diagnosis and the guidance it provides in disease prognosis.
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Genetic causes of proteinuria and nephrotic syndrome: impact on podocyte pathobiology. Pediatr Nephrol 2015; 30:221-33. [PMID: 24584664 PMCID: PMC4262721 DOI: 10.1007/s00467-014-2753-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 12/31/2013] [Accepted: 01/02/2014] [Indexed: 12/11/2022]
Abstract
In the past 20 years, multiple genetic mutations have been identified in patients with congenital nephrotic syndrome (CNS) and both familial and sporadic focal segmental glomerulosclerosis (FSGS). Characterization of the genetic basis of CNS and FSGS has led to the recognition of the importance of podocyte injury to the development of glomerulosclerosis. Genetic mutations induce injury due to effects on the podocyte's structure, actin cytoskeleton, calcium signaling, and lysosomal and mitochondrial function. Transgenic animal studies have contributed to our understanding of podocyte pathobiology. Podocyte endoplasmic reticulum stress response, cell polarity, and autophagy play a role in maintenance of podocyte health. Further investigations related to the effects of genetic mutations on podocytes may identify new pathways for targeting therapeutics for nephrotic syndrome.
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Franke D, Thomas L, Steffens R, Pavičić L, Gellermann J, Froede K, Querfeld U, Haffner D, Živičnjak M. Patterns of growth after kidney transplantation among children with ESRD. Clin J Am Soc Nephrol 2014; 10:127-34. [PMID: 25352379 DOI: 10.2215/cjn.02180314] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Poor linear growth is a frequent complication of CKD. This study evaluated the effect of kidney transplantation on age-related growth of linear body segments in pediatric renal transplant recipients who were enrolled from May 1998 until August 2013 in the CKD Growth and Development observational cohort study. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Linear growth (height, sitting height, arm and leg lengths) was prospectively investigated during 1639 annual visits in a cohort of 389 pediatric renal transplant recipients ages 2-18 years with a median follow-up of 3.4 years (interquartile range, 1.9-5.9 years). Linear mixed-effects models were used to assess age-related changes and predictors of linear body segments. RESULTS During early childhood, patients showed lower mean SD scores (SDS) for height (-1.7) and a markedly elevated sitting height index (ratio of sitting height to total body height) compared with healthy children (1.6 SDS), indicating disproportionate stunting (each P<0.001). After early childhood a sustained increase in standardized leg length and a constant decrease in standardized sitting height were noted (each P<0.001), resulting in significant catch-up growth and almost complete normalization of sitting height index by adult age (0.4 SDS; P<0.01 versus age 2-4 years). Time after transplantation, congenital renal disease, bone maturation, steroid exposure, degree of metabolic acidosis and anemia, intrauterine growth restriction, and parental height were significant predictors of linear body dimensions and body proportions (each P<0.05). CONCLUSIONS Children with ESRD present with disproportionate stunting. In pediatric renal transplant recipients, a sustained increase in standardized leg length and total body height is observed from preschool until adult age, resulting in restoration of body proportions in most patients. Reduction of steroid exposure and optimal metabolic control before and after transplantation are promising measures to further improve growth outcome.
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Affiliation(s)
- Doris Franke
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children's Hospital, Hannover Medical School, Hannover, Germany
| | - Lena Thomas
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children's Hospital, Hannover Medical School, Hannover, Germany
| | - Rena Steffens
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children's Hospital, Hannover Medical School, Hannover, Germany
| | - Leo Pavičić
- Faculty of Kinesiology, University of Zagreb, Zagreb, Croatia; and
| | - Jutta Gellermann
- Department of Pediatric Nephrology, Charité University Hospital, Berlin, Germany
| | - Kerstin Froede
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children's Hospital, Hannover Medical School, Hannover, Germany
| | - Uwe Querfeld
- Department of Pediatric Nephrology, Charité University Hospital, Berlin, Germany
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children's Hospital, Hannover Medical School, Hannover, Germany
| | - Miroslav Živičnjak
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children's Hospital, Hannover Medical School, Hannover, Germany;
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Sarin S, Javidan A, Boivin F, Alexopoulou I, Lukic D, Svajger B, Chu S, Baradaran-Heravi A, Boerkoel CF, Rosenblum ND, Bridgewater D. Insights into the renal pathogenesis in Schimke immuno-osseous dysplasia: A renal histological characterization and expression analysis. J Histochem Cytochem 2014; 63:32-44. [PMID: 25319549 DOI: 10.1369/0022155414558335] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Schimke immuno-osseous dysplasia (SIOD) is a pleiotropic disorder caused by mutations in the SWI/SNF2-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like-1 (SMARCAL1) gene, with multiple clinical features, notably end-stage renal disease. Here we characterize the renal pathology in SIOD patients. Our analysis of SIOD patient renal biopsies demonstrates the tip and collapsing variants of focal segmental glomerulosclerosis (FSGS). Additionally, electron microscopy revealed numerous glomerular abnormalities most notably in the podocyte and Bowman's capsule. To better understand the role of SMARCAL1 in the pathogenesis of FSGS, we defined SMARCAL1 expression in the developing and mature kidney. In the developing fetal kidney, SMARCAL1 is expressed in the ureteric epithelium, stroma, metanephric mesenchyme, and in all stages of the developing nephron, including the maturing glomerulus. In postnatal kidneys, SMARCAL1 expression is localized to epithelial tubules of the nephron, collecting ducts, and glomerulus (podocytes and endothelial cells). Interestingly, not all cells within the same lineage expressed SMARCAL1. In renal biopsies from SIOD patients, TUNEL analysis detected marked increases in DNA fragmentation. Our results highlight the cells that may contribute to the renal pathogenesis in SIOD. Further, we suggest that disruptions in genomic integrity during fetal kidney development contribute to the pathogenesis of FSGS in SIOD patients.
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Affiliation(s)
- Sanjay Sarin
- Program in Pathology and Molecular Medicine, McMaster University, Hamilton, Canada (SS, AJ, FB, IA, BS, SC, DL, DB)
| | - Ashkan Javidan
- Program in Pathology and Molecular Medicine, McMaster University, Hamilton, Canada (SS, AJ, FB, IA, BS, SC, DL, DB)
| | - Felix Boivin
- Program in Pathology and Molecular Medicine, McMaster University, Hamilton, Canada (SS, AJ, FB, IA, BS, SC, DL, DB)
| | - Iakovina Alexopoulou
- Program in Pathology and Molecular Medicine, McMaster University, Hamilton, Canada (SS, AJ, FB, IA, BS, SC, DL, DB)
| | - Dusan Lukic
- Program in Pathology and Molecular Medicine, McMaster University, Hamilton, Canada (SS, AJ, FB, IA, BS, SC, DL, DB)
| | - Bruno Svajger
- Program in Pathology and Molecular Medicine, McMaster University, Hamilton, Canada (SS, AJ, FB, IA, BS, SC, DL, DB)
| | - Stephanie Chu
- Program in Pathology and Molecular Medicine, McMaster University, Hamilton, Canada (SS, AJ, FB, IA, BS, SC, DL, DB)
| | - Alireza Baradaran-Heravi
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada (ABH, CFB)
| | - Cornelius F Boerkoel
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada (ABH, CFB),Department of Medical Genetics, University of British Columbia, Vancouver, Canada (CFB)
| | - Norman D Rosenblum
- Department of Pediatrics, Division of Nephrology, The Hospital for Sick Children, University of Toronto, Toronto, Canada (NDR)
| | - Darren Bridgewater
- Program in Pathology and Molecular Medicine, McMaster University, Hamilton, Canada (SS, AJ, FB, IA, BS, SC, DL, DB)
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Santangelo L, Gigante M, Netti GS, Diella S, Puteo F, Carbone V, Grandaliano G, Giordano M, Gesualdo L. A novel SMARCAL1 mutation associated with a mild phenotype of Schimke immuno-osseous dysplasia (SIOD). BMC Nephrol 2014; 15:41. [PMID: 24589093 PMCID: PMC3973878 DOI: 10.1186/1471-2369-15-41] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 02/25/2014] [Indexed: 11/17/2022] Open
Abstract
Background Schimke immuno-osseous dysplasia (SIOD, OMIM #242900) is an autosomal-recessive pleiotropic disorder characterized by spondyloepiphyseal dysplasia, renal dysfunction and T-cell immunodeficiency. SIOD is caused by mutations in the gene SMARCAL1. Case presentation We report the clinical and genetic diagnosis of a 5-years old girl with SIOD, referred to our Center because of nephrotic-range proteinuria occasionally detected during the follow-up for congenital hypothyroidism. Mutational analysis of SMARCAL1 gene was performed by polymerase chain reaction (PCR) and bidirectional sequencing. Sequence analysis revealed that patient was compound heterozygous for two SMARCAL1 mutations: a novel missense change (p.Arg247Pro) and a well-known nonsense mutation (p.Glu848*). Conclusion This report provided the clinical and genetic description of a mild phenotype of Schimke immuno-osseous dysplasia associated with nephrotic proteinuria, decreasing after combined therapy with ACE inhibitors and sartans. Our experience highlighted the importance of detailed clinical evaluation, appropriate genetic counseling and molecular testing, to provide timely treatment and more accurate prognosis.
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Affiliation(s)
| | | | | | | | | | | | | | - Mario Giordano
- Unit of Pediatric Nephrology, University Hospital "Policlinico Consorziale - Giovanni XXIII", Bari, Italy.
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Classen CF, Riehmer V, Landwehr C, Kosfeld A, Heilmann S, Scholz C, Kabisch S, Engels H, Tierling S, Zivicnjak M, Schacherer F, Haffner D, Weber RG. Dissecting the genotype in syndromic intellectual disability using whole exome sequencing in addition to genome-wide copy number analysis. Hum Genet 2013; 132:825-41. [PMID: 23552953 DOI: 10.1007/s00439-013-1296-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 03/15/2013] [Indexed: 12/31/2022]
Abstract
When a known microimbalance affecting multiple genes is detected in a patient with syndromic intellectual disability, it is usually presumed causative for all observed features. Whole exome sequencing (WES) allows questioning this assumption. In this study of three families with children affected by unexplained syndromic intellectual disability, genome-wide copy number and subsequent analyses revealed a de novo maternal 1.1 Mb microdeletion in the 14q32 imprinted region causing a paternal UPD(14)-like phenotype, and two inherited 22q11.21 microduplications of 2.5 or 2.8 Mb. In patient 1 carrying the 14q32 microdeletion, tall stature and renal malformation were unexplained by paternal UPD(14), and there was no altered DLK1 expression or unexpected methylation status. By WES and filtering with a mining tool, a novel FBN1 missense variant was found in patient 1 and his mother, who both showed clinical features of Marfan syndrome by thorough anthropometric assessment, and a novel EYA1 missense variant as a probable cause of the renal malformation in the patient. In patient 2 with the 22q11.21 microduplication syndrome, skin hypo- and hyperpigmentation and two malignancies were only partially explained. By WES, compound heterozygous BLM stop founder mutations were detected causing Bloom syndrome. In male patient 3 carrying a 22q11.21 microduplication inherited from his unaffected father, WES identified a novel missense variant in the OPHN1 X-linked intellectual disability gene inherited from the unaffected mother as a possible additional cause for developmental delay. Thus, WES seems warranted in patients carrying microdeletions or microduplications, who have unexplained clinical features or microimbalances inherited from an unaffected parent.
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Affiliation(s)
- Carl Friedrich Classen
- Department of Pediatrics, University Hospital, Ernst-Heydemann-Str. 8, 18057 Rostock, Germany
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Progress in pathogenesis of proteinuria. Int J Nephrol 2012; 2012:314251. [PMID: 22693670 PMCID: PMC3368192 DOI: 10.1155/2012/314251] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2012] [Revised: 03/24/2012] [Accepted: 03/26/2012] [Indexed: 02/06/2023] Open
Abstract
Aims. Proteinuria not only is a sign of kidney damage, but also is involved in the progression of renal diseases as an independent pathologic factor. Clinically, glomerular proteinuria is most commonly observed, which relates to structural and functional anomalies in the glomerular filtration barrier. The aim of this paper was to describe the pathogenesis of glomerular proteinuria. Data Sources. Articles on glomerular proteinuria retrieved from Pubmed and MEDLINE in the recent 5 years were reviewed. Results. The new understanding of the roles of glomerular endothelial cells and the glomerular basement membrane (GBM) in the pathogenesis of glomerular proteinuria was gained. The close relationships of slit diaphragm (SD) molecules such as nephrin, podocin, CD2-associated protein (CD2AP), a-actinin-4, transient receptor potential cation channel 6 (TRPC6), Densin and membrane-associated guanylate kinase inverted 1 (MAGI-1), α3β1 integrin, WT1, phospholipase C epsilon-1 (PLCE1), Lmx1b, and MYH9, and mitochondrial disorders and circulating factors in the pathogenesis of glomerular proteinuria were also gradually discovered. Conclusion. Renal proteinuria is a manifestation of glomerular filtration barrier dysfunction. Not only glomerular endothelial cells and GBM, but also the glomerular podocytes and their SDs play an important role in the pathogenesis of glomerular proteinuria.
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Molecular genetic analysis of podocyte genes in focal segmental glomerulosclerosis--a review. Eur J Pediatr 2009; 168:1291-304. [PMID: 19562370 PMCID: PMC2745545 DOI: 10.1007/s00431-009-1017-x] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Accepted: 06/12/2009] [Indexed: 01/15/2023]
Abstract
This review deals with podocyte proteins that play a significant role in the structure and function of the glomerular filter. Genetic linkage studies has identified several genes involved in the development of nephrotic syndrome and contributed to the understanding of the pathophysiology of glomerular proteinuria and/or focal segmental glomerulosclerosis. Here, we describe already well-characterized genetic diseases due to mutations in nephrin, podocin, CD2AP, alpha-actinin-4, WT1, and laminin beta2 chain, as well as more recently identified genetic abnormalities in TRPC6, phospholipase C epsilon, and the proteins encoded by the mitochondrial genome. In addition, the role of the proteins which have shown to be important for the structure and functions by gene knockout studies in mice, are also discussed. Furthermore, some rare syndromes with glomerular involvement, in which molecular defects have been recently identified, are briefly described. In summary, this review updates the current knowledge of genetic causes of congenital and childhood nephrotic syndrome and provides new insights into mechanisms of glomerular dysfunction.
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