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Du R, Zhou C, Chen S, Li T, Lin Y, Xu A, Huang Y, Mei H, Huang X, Tan D, Zheng R, Liang C, Cai Y, Shao Y, Zhang W, Liu L, Zeng C. Atypical phenotypes and novel OCRL variations in southern Chinese patients with Lowe syndrome. Pediatr Nephrol 2024; 39:2377-2391. [PMID: 38589698 DOI: 10.1007/s00467-024-06356-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 03/06/2024] [Accepted: 03/07/2024] [Indexed: 04/10/2024]
Abstract
BACKGROUND Lowe syndrome is characterized by the presence of congenital cataracts, psychomotor retardation, and dysfunctional proximal renal tubules. This study presents a case of an atypical phenotype, investigates the genetic characteristics of eight children diagnosed with Lowe syndrome in southern China, and performs functional analysis of the novel variants. METHODS Whole-exome sequencing was conducted on eight individuals diagnosed with Lowe syndrome from three medical institutions in southern China. Retrospective collection and analysis of clinical and genetic data were performed, and functional analysis was conducted on the five novel variants. RESULTS In our cohort, the clinical symptoms of the eight Lowe syndrome individuals varied. One patient was diagnosed with Lowe syndrome but did not present with congenital cataracts. Common features among all patients included cognitive impairment, short stature, and low molecular weight proteinuria. Eight variations in the OCRL gene were identified, encompassing three previously reported and five novel variations. Among the novel variations, three nonsense mutations were determined to be pathogenic, and two patients harboring novel missense variations of uncertain significance exhibited severe typical phenotypes. Furthermore, all novel variants were associated with altered protein expression levels and impacted primary cilia formation. CONCLUSION This study describes the first case of an atypical Lowe syndrome patient without congenital cataracts in China and performs a functional analysis of novel variants in the OCRL gene, thereby expanding the understanding of the clinical manifestations and genetic diversity associated with Lowe syndrome.
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Affiliation(s)
- Rong Du
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
- Department of Endocrinology, Genetic, and Rare Diseases, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China
| | - Chengcheng Zhou
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Shehong Chen
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
- Department of Pediatrics, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, China
| | - Tong Li
- Department of Pediatric Endocrinology, The First Affiliated Hospital of Shantou University Medical College, Shantou, 515041, China
| | - Yunting Lin
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Aijing Xu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Yonglan Huang
- Department of Guangzhou Newborn Screening Center, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Huifen Mei
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
- Department of Endocrinology, Genetic, and Rare Diseases, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China
| | - Xiaoli Huang
- Department of Pediatric Neurology, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China
| | - Dongdong Tan
- Department of Endocrinology, Genetic, and Rare Diseases, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China
| | - Ruidan Zheng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Cuili Liang
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Yanna Cai
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Yongxian Shao
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Wen Zhang
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
- Department of Endocrinology, Genetic, and Rare Diseases, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China
| | - Li Liu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
- Department of Endocrinology, Genetic, and Rare Diseases, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China
| | - Chunhua Zeng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China.
- Department of Endocrinology, Genetic, and Rare Diseases, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China.
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Gwack J, Kim N, Park J. Improving the Yield of Genetic Diagnosis through Additional Genetic Panel Testing in Hereditary Ophthalmic Diseases. Curr Issues Mol Biol 2024; 46:5010-5022. [PMID: 38785568 PMCID: PMC11119902 DOI: 10.3390/cimb46050300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 05/17/2024] [Accepted: 05/18/2024] [Indexed: 05/25/2024] Open
Abstract
Numerous hereditary ophthalmic diseases display significant genetic diversity. Consequently, the utilization of gene panel sequencing allows a greater number of patients to receive a genetic diagnosis for their clinical manifestations. We investigated how to improve the yield of genetic diagnosis through additional gene panel sequencing in hereditary ophthalmic diseases. A gene panel sequencing consisting of a customized hereditary retinopathy panel or hereditary retinitis pigmentosa (RP) panel was prescribed and referred to a CAP-accredited clinical laboratory. If no significant mutations associated with hereditary retinopathy and RP were detected in either panel, additional gene panel sequencing was requested for research use, utilizing the remaining panel. After additional gene panel sequencing, a total of 16 heterozygous or homozygous variants were identified in 15 different genes associated with hereditary ophthalmic diseases. Of 15 patients carrying any candidate variants, the clinical symptoms could be tentatively accounted for by genetic mutations in seven patients. However, in the remaining eight patients, given the in silico mutation predictive analysis, variant allele frequency in gnomAD, inheritance pattern, and genotype-phenotype correlation, fully elucidating the clinical manifestations with the identified rare variant was challenging. Our study highlights the utility of gene panel sequencing in achieving accurate diagnoses for hereditary ophthalmic diseases and enhancing the diagnostic yield through additional gene panel sequencing. Thus, gene panel sequencing can serve as a primary tool for the genetic diagnosis of hereditary ophthalmic diseases, even in cases where a single genetic cause is suspected. With a deeper comprehension of the genetic mechanisms underlying these diseases, it becomes feasible.
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Affiliation(s)
- Jin Gwack
- Department of Preventive Medicine, Jeonbuk National University Medical School, Jeonju 54907, Republic of Korea;
| | - Namsu Kim
- Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju 54907, Republic of Korea;
- Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju 54907, Republic of Korea
| | - Joonhong Park
- Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju 54907, Republic of Korea;
- Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju 54907, Republic of Korea
- Department of Laboratory Medicine, Daejeon St. Mary’s Hospital, Daejeon 34943, Republic of Korea
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3
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Campbell L, Fredericks J, Mathivha K, Moshesh P, Coovadia A, Chirwa P, Dillon B, Ghoor A, Lawrence D, Nair L, Mabaso N, Mokwele D, Novellie M, Krause A, Carstens N. The implementation and utility of clinical exome sequencing in a South African infant cohort. Front Genet 2023; 14:1277948. [PMID: 38028619 PMCID: PMC10665497 DOI: 10.3389/fgene.2023.1277948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Genetic disorders are significant contributors to infant hospitalization and mortality globally. The early diagnosis of these conditions in infants remains a considerable challenge. Clinical exome sequencing (CES) has shown to be a successful tool for the early diagnosis of genetic conditions, however, its utility in African infant populations has not been investigated. The impact of the under-representation of African genomic data, the cost of testing, and genomic workforce shortages, need to be investigated and evidence-based implementation strategies accounting for locally available genetics expertise and diagnostic infrastructure need to be developed. We evaluated the diagnostic utility of singleton CES in a cohort of 32 ill, South African infants from two State hospitals in Johannesburg, South Africa. We analysed the data using a series of filtering approaches, including a curated virtual gene panel consisting of genes implicated in neonatal-and early childhood-onset conditions and genes with known founder and common variants in African populations. We reported a diagnostic yield of 22% and identified seven pathogenic variants in the NPHS1, COL2A1, OCRL, SHOC2, TPRV4, MTM1 and STAC3 genes. This study demonstrates the utility value of CES in the South African State healthcare setting, providing a diagnosis to patients who would otherwise not receive one and allowing for directed management. We anticipate an increase in the diagnostic yield of our workflow with further refinement of the study inclusion criteria. This study highlights important considerations for the implementation of genomic medicine in under-resourced settings and in under-represented African populations where variant interpretation remains a challenge.
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Affiliation(s)
- L. Campbell
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - J. Fredericks
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - K. Mathivha
- Department of Paediatrics and Child Health, School of Clinical Medicine, Nelson Mandela Children’s Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - P. Moshesh
- Department of Paediatrics and Child Health, School of Clinical Medicine, Nelson Mandela Children’s Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - A. Coovadia
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - P. Chirwa
- Nelson Mandela Children’s Hospital, Johannesburg, South Africa
| | - B. Dillon
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - A. Ghoor
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - D. Lawrence
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - L. Nair
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - N. Mabaso
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - D. Mokwele
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - M. Novellie
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - A. Krause
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - N. Carstens
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Genomics Platform, South African Medical Research Council, Cape Town, South Africa
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Bura A, de Matteis MA, Bender M, Swinkels M, Versluis J, Jansen AJG, Jurak Begonja A. Oculocerebrorenal syndrome of Lowe protein controls cytoskeletal reorganisation during human platelet spreading. Br J Haematol 2023; 200:87-99. [PMID: 36176266 DOI: 10.1111/bjh.18478] [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: 05/10/2022] [Revised: 09/05/2022] [Accepted: 09/14/2022] [Indexed: 11/28/2022]
Abstract
Lowe syndrome (LS) is a rare, X-linked disorder characterised by numerous symptoms affecting the brain, the eyes, and the kidneys. It is caused by mutations in the oculocerebrorenal syndrome of Lowe (OCRL) protein, a 5-phosphatase localised in different cellular compartments that dephosphorylates phosphatidylinositol-4,5-bisphosphate into phosphatidylinositol-4-monophosphate. Some patients with LS also have bleeding disorders, with normal to low platelet (PLT) count and impaired PLT function. However, the mechanism of PLT dysfunction in patients with LS is not completely understood. The main function of PLTs is to activate upon vessel wall injury and stop the bleeding by clot formation. PLT activation is accompanied by a shape change that is a result of massive cytoskeletal rearrangements. Here, we show that OCRL-inhibited human PLTs do not fully spread, form mostly filopodia, and accumulate actin nodules. These nodules co-localise with ARP2/3 subunit p34, vinculin, and sorting nexin 9. Furthermore, OCRL-inhibited PLTs have a retained microtubular coil with high levels of acetylated tubulin. Also, myosin light chain phosphorylation is decreased upon OCRL inhibition, without impaired degranulation or integrin activation. Taken together, these results suggest that OCRL contributes to cytoskeletal rearrangements during PLT activation that could explain mild bleeding problems in patients with LS.
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Affiliation(s)
- Ana Bura
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
| | - Maria Antonietta de Matteis
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli, Naples, Italy.,Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Markus Bender
- Institute of Experimental Biomedicine, University Hospital Wuerzburg, Rudolf Virchow Center, Wuerzburg, Germany
| | - Maurice Swinkels
- Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Jurjen Versluis
- Erasmus MC University Medical Center, Rotterdam, the Netherlands
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5
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Sena C, Iannello G, Skowronski AA, Dannheim K, Cheung L, Agrawal PB, Hirschhorn JN, Zeitler P, LeDuc CA, Stratigopoulos G, Thaker VV. Endocrine and behavioural features of Lowe syndrome and their potential molecular mechanisms. J Med Genet 2022; 59:1171-1178. [PMID: 35803701 PMCID: PMC10186212 DOI: 10.1136/jmedgenet-2022-108490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 06/11/2022] [Indexed: 01/12/2023]
Abstract
BACKGROUND Lowe syndrome (LS) is an X linked disease caused by pathogenic variants in the OCRL gene that impacts approximately 1 in 500 000 children. Classic features include congenital cataract, cognitive/behavioural impairment and renal tubulopathy. METHODS This study is a retrospective review of clinical features reported by family based survey conducted by Lowe Syndrome Association. Frequency of non-ocular clinical feature(s) of LS and their age of onset was summarised. An LS-specific therapy effectiveness scale was used to assess the response to the administered treatment. Expression of OCRL and relevant neuropeptides was measured in postmortem human brain by qPCR. Gene expression in the mouse brain was determined by reanalysis of publicly available bulk and single cell RNA sequencing. RESULTS A total of 137 individuals (1 female, 89.1% white, median age 14 years (range 0.8-56)) were included in the study. Short stature (height <3rd percentile) was noted in 81% (n=111) individuals, and 15% (n=20) received growth hormone therapy. Undescended testis was reported in 47% (n=64), and median age of onset of puberty was 15 years. Additional features were dental problems (n=77, 56%), bone fractures (n=63, 46%), hypophosphataemia (n=60, 44%), developmental delay and behavioural issues. OCRL is expressed in human and mouse hypothalami, and in hypothalamic cell clusters expressing Ghrh, Sst, Oxt, Pomc and pituitary cells expressing Gh and Prl. CONCLUSIONS There is a wide spectrum of the clinical phenotype of LS. Some of the features may be partly driven by the loss of function of OCRL in the hypothalamus and the pituitary.
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Affiliation(s)
- Cecilia Sena
- Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, New York, USA
| | - Grazia Iannello
- Columbia Stem Cell Initiative, Stem Cell Core, Columbia University Irving Medical Center, New York, New York, USA
| | - Alicja A Skowronski
- Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, New York, USA
| | - Katelyn Dannheim
- Department of Pathology and Laboratory Medicine, Rhode Island and Hasbro Children's Hospitals and the Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Leonard Cheung
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Pankaj B Agrawal
- Division of Neonatology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Joel N Hirschhorn
- Division of Endocrinology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Phillip Zeitler
- Department of Endocrinology, Children's Hospital Colorado, Aurora, Colorado, USA
| | - Charles A LeDuc
- Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, New York, USA
| | - George Stratigopoulos
- Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, New York, USA
| | - Vidhu V Thaker
- Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, New York, USA
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Gianesello L, Arroyo J, Del Prete D, Priante G, Ceol M, Harris PC, Lieske JC, Anglani F. Genotype Phenotype Correlation in Dent Disease 2 and Review of the Literature: OCRL Gene Pleiotropism or Extreme Phenotypic Variability of Lowe Syndrome? Genes (Basel) 2021; 12:1597. [PMID: 34680992 PMCID: PMC8535715 DOI: 10.3390/genes12101597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/30/2021] [Accepted: 10/05/2021] [Indexed: 11/29/2022] Open
Abstract
Dent disease is a rare X-linked renal tubulopathy due to CLCN5 and OCRL (DD2) mutations. OCRL mutations also cause Lowe syndrome (LS) involving the eyes, brain and kidney. DD2 is frequently described as a mild form of LS because some patients may present with extra-renal symptoms (ESs). Since DD2 is a rare disease and there are a low number of reported cases, it is still unclear whether it has a clinical picture distinct from LS. We retrospectively analyzed the phenotype and genotype of our cohort of 35 DD2 males and reviewed all published DD2 cases. We analyzed the distribution of mutations along the OCRL gene and evaluated the type and frequency of ES according to the type of mutation and localization in OCRL protein domains. The frequency of patients with at least one ES was 39%. Muscle findings are the most common ES (52%), while ocular findings are less common (11%). Analysis of the distribution of mutations revealed (1) truncating mutations map in the PH and linker domain, while missense mutations map in the 5-phosphatase domain, and only occasionally in the ASH-RhoGAP module; (2) five OCRL mutations cause both DD2 and LS phenotypes; (3) codon 318 is a DD2 mutational hot spot; (4) a correlation was found between the presence of ES and the position of the mutations along OCRL domains. DD2 is distinct from LS. The mutation site and the mutation type largely determine the DD2 phenotype.
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Affiliation(s)
- Lisa Gianesello
- Kidney Histomorphology and Molecular Biology Laboratory, Nephrology, Dialysis and Transplantation Unit, Department of Medicine-DIMED, University of Padua, 35128 Padua, Italy; (L.G.); (D.D.P.); (G.P.); (M.C.)
| | - Jennifer Arroyo
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, USA; (J.A.); (P.C.H.); (J.C.L.)
| | - Dorella Del Prete
- Kidney Histomorphology and Molecular Biology Laboratory, Nephrology, Dialysis and Transplantation Unit, Department of Medicine-DIMED, University of Padua, 35128 Padua, Italy; (L.G.); (D.D.P.); (G.P.); (M.C.)
| | - Giovanna Priante
- Kidney Histomorphology and Molecular Biology Laboratory, Nephrology, Dialysis and Transplantation Unit, Department of Medicine-DIMED, University of Padua, 35128 Padua, Italy; (L.G.); (D.D.P.); (G.P.); (M.C.)
| | - Monica Ceol
- Kidney Histomorphology and Molecular Biology Laboratory, Nephrology, Dialysis and Transplantation Unit, Department of Medicine-DIMED, University of Padua, 35128 Padua, Italy; (L.G.); (D.D.P.); (G.P.); (M.C.)
| | - Peter C. Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, USA; (J.A.); (P.C.H.); (J.C.L.)
| | - John C. Lieske
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, USA; (J.A.); (P.C.H.); (J.C.L.)
| | - Franca Anglani
- Kidney Histomorphology and Molecular Biology Laboratory, Nephrology, Dialysis and Transplantation Unit, Department of Medicine-DIMED, University of Padua, 35128 Padua, Italy; (L.G.); (D.D.P.); (G.P.); (M.C.)
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7
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Madhivanan K, Ramadesikan S, Hsieh WC, Aguilar MC, Hanna CB, Bacallao RL, Aguilar RC. Lowe syndrome patient cells display mTOR- and RhoGTPase-dependent phenotypes alleviated by rapamycin and statins. Hum Mol Genet 2021; 29:1700-1715. [PMID: 32391547 DOI: 10.1093/hmg/ddaa086] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/20/2020] [Accepted: 05/04/2020] [Indexed: 12/25/2022] Open
Abstract
Lowe syndrome (LS) is an X-linked developmental disease characterized by cognitive deficiencies, bilateral congenital cataracts and renal dysfunction. Unfortunately, this disease leads to the early death of affected children often due to kidney failure. Although this condition was first described in the early 1950s and the affected gene (OCRL1) was identified in the early 1990s, its pathophysiological mechanism is not fully understood and there is no LS-specific cure available to patients. Here we report two important signaling pathways affected in LS patient cells. While RhoGTPase signaling abnormalities led to adhesion and spreading defects as compared to normal controls, PI3K/mTOR hyperactivation interfered with primary cilia assembly (scenario also observed in other ciliopathies with compromised kidney function). Importantly, we identified two FDA-approved drugs able to ameliorate these phenotypes. Specifically, statins mitigated adhesion and spreading abnormalities while rapamycin facilitated ciliogenesis in LS patient cells. However, no single drug was able to alleviate both phenotypes. Based on these and other observations, we speculate that Ocrl1 has dual, independent functions supporting proper RhoGTPase and PI3K/mTOR signaling. Therefore, this study suggest that Ocrl1-deficiency leads to signaling defects likely to require combinatorial drug treatment to suppress patient phenotypes and symptoms.
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Affiliation(s)
- Kayalvizhi Madhivanan
- Department of Biological Sciences, Purdue University, Hansen Life Sciences Building, Room 321, 201 S. University street, West Lafayette, IN 47907, USA
| | - Swetha Ramadesikan
- Department of Biological Sciences, Purdue University, Hansen Life Sciences Building, Room 321, 201 S. University street, West Lafayette, IN 47907, USA
| | - Wen-Chieh Hsieh
- Department of Biological Sciences, Purdue University, Hansen Life Sciences Building, Room 321, 201 S. University street, West Lafayette, IN 47907, USA
| | - Mariana C Aguilar
- Department of Biological Sciences, Purdue University, Hansen Life Sciences Building, Room 321, 201 S. University street, West Lafayette, IN 47907, USA
| | - Claudia B Hanna
- Department of Biological Sciences, Purdue University, Hansen Life Sciences Building, Room 321, 201 S. University street, West Lafayette, IN 47907, USA
| | - Robert L Bacallao
- Division of Nephrology, Indiana University School of Medicine, 340 W 10th St #6200, Indianapolis, IN 46202, USA
| | - R Claudio Aguilar
- Department of Biological Sciences, Purdue University, Hansen Life Sciences Building, Room 321, 201 S. University street, West Lafayette, IN 47907, USA
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8
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Chen KJ, Wu HR, Chao MC, Chang TM, Chien JW, Chen M, Ma GC, Ke YY. Genotype and phenotype studies of Lowe syndrome in three families in Taiwan. Pediatr Neonatol 2021; 62:327-328. [PMID: 33745830 DOI: 10.1016/j.pedneo.2021.01.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/07/2021] [Accepted: 01/27/2021] [Indexed: 11/30/2022] Open
Affiliation(s)
- Kuan-Jung Chen
- Division of Pediatric Genetics and Metabolism, Changhua Christian Children's Hospital, Changhua, Taiwan
| | - Hsin-Ru Wu
- Division of Pediatric Genetics and Metabolism, Changhua Christian Children's Hospital, Changhua, Taiwan
| | - Mei-Chyn Chao
- Division of Pediatric Genetics and Metabolism, Changhua Christian Children's Hospital, Changhua, Taiwan.
| | - Tung-Ming Chang
- Division of Pediatric Neurology, Changhua Christian Children's Hospital, Changhua, Taiwan
| | - Jien-Wen Chien
- Division of Pediatric Nephrology, Changhua Christian Children's Hospital, Changhua, Taiwan
| | - Ming Chen
- Department of Genomic Medicine and Center for Medical Genetics, Changhua Christian Hospital, Changhua, Taiwan
| | - Gwo-Chin Ma
- Department of Genomic Medicine and Center for Medical Genetics, Changhua Christian Hospital, Changhua, Taiwan
| | - Yu-Yuan Ke
- Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan
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9
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Parikh AC, Gadgil P. Lowe Syndrome: A Complex Clinical Diagnosis with a Novel Mutation in the OCRL Gene. JOURNAL OF CHILD SCIENCE 2021. [DOI: 10.1055/s-0041-1724042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AbstractLowe syndrome (LS) is a rare X-linked condition having a clinical triad of congenital cataracts, intellectual disability, and progressive tubular nephropathy. Although the easily recognizable symptom complex usually evolves by infancy, a unifying diagnosis is often missed. We present a young boy with a prolonged history of multisystem affection, finally leading to the clinical suspicion of LS. The diagnosis was confirmed on genetic analysis as well as a previously unreported mutation in the OCRL gene was discovered. A 9-year-old boy with intellectual disability and recent onset seizures was referred for the evaluation of rickets. In addition, there was a significant past history of neonatal cataracts, infantile glaucoma, persistent albuminuria, and severe short stature with growth hormone deficiency. The characteristic involvement of eyes, brain, and kidneys along with a family history of a maternal uncle being similarly affected led to the clinical suspicion of LS. A whole exome sequencing was performed, which not only confirmed a nonsense mutation, c.2530C > T, in exon 23 of the Lowe gene (OCRL) but also revealed it to be a novel pathogenic variant. This case highlights the importance of piecing together the different facets of a complex clinical syndrome in reaching a challenging diagnosis. Also, LS must be kept as a differential in any child with neonatal cataracts and intellectual disability. Genetic confirmation of LS in our patient partly relieved the parental anxiety, and the child continued to remain under follow-up with multiple specialists, only now with a definite diagnosis.
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Affiliation(s)
- Akanksha C. Parikh
- Kokilaben Dhirubhai Ambani Hospital and Medical Research Institute, Mumbai, Maharashtra, India
| | - Pradnya Gadgil
- Kokilaben Dhirubhai Ambani Hospital and Medical Research Institute, Mumbai, Maharashtra, India
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Perdomo-Ramirez A, Antón-Gamero M, Rizzo DS, Trindade A, Ramos-Trujillo E, Claverie-Martin F. Two new missense mutations in the protein interaction ASH domain of OCRL1 identified in patients with Lowe syndrome. Intractable Rare Dis Res 2020; 9:222-228. [PMID: 33139981 PMCID: PMC7586875 DOI: 10.5582/irdr.2020.03092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The oculocerebrorenal syndrome of Lowe is a rare X-linked disease characterized by congenital cataracts, proximal renal tubulopathy, muscular hypotonia and mental impairment. This disease is caused by mutations in the OCRL gene encoding membrane bound inositol polyphosphate 5-phosphatase OCRL1. Here, we examined the OCRL gene of two Lowe syndrome patients and report two new missense mutations that affect the ASH domain involved in protein-protein interactions. Genomic DNA was extracted from peripheral blood of two non-related patients and their relatives. Exons and flanking intronic regions of OCRL were analyzed by direct sequencing. Several bioinformatics tools were used to assess the pathogenicity of the variants. The three-dimensional structure of wild-type and mutant ASH domains was modeled using the online server SWISS-MODEL. Clinical features suggesting the diagnosis of Lowe syndrome were observed in both patients. Genetic analysis revealed two novel missense variants, c.1907T>A (p.V636E) and c.1979A>C (p.H660P) in exon 18 of the OCRL gene confirming the clinical diagnosis in both cases. Variant c.1907T>A (p.V636E) was inherited from the patient's mother, while variant c.1979A>C (p.H660P) seems to have originated de novo. Analysis with bioinformatics tools indicated that both variants are pathogenic. Both amino acid changes affect the structure of the OCRL1 ASH domain. In conclusion, the identification of two novel missense mutations located in the OCRL1 ASH domain may shed more light on the functional importance of this domain. We suggest that p.V636E and p.H660P cause Lowe syndrome by disrupting the interaction of OCRL1 with other proteins or by impairing protein stability.
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Affiliation(s)
- Ana Perdomo-Ramirez
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | | | | | - Amelia Trindade
- Departamento de Medicina, Universidade Federal de Sao Carlos, Sao Paulo, Brazil
| | - Elena Ramos-Trujillo
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Felix Claverie-Martin
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
- Address correspondence to:Félix Claverie-Martín, Unidad de Investigación, Hospital Nuestra Señora de Candelaria, Carretera del Rosario 145, 38010 Santa Cruz de Tenerife, Spain. E-mail:
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Incomplete cryptic splicing by an intronic mutation of OCRL in patients with partial phenotypes of Lowe syndrome. J Hum Genet 2020; 65:831-839. [PMID: 32427950 DOI: 10.1038/s10038-020-0773-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 05/01/2020] [Accepted: 05/01/2020] [Indexed: 01/03/2023]
Abstract
Mutations of OCRL cause Lowe syndrome, which is characterised by congenital cataracts, infantile hypotonia with mental retardation, and renal tubular dysfunction and Dent-2 disease, which only affects the kidney. While few patients with an intermediate phenotype between these diseases have been reported, the mechanism underlying variability in the phenotype is unclear. We identified an intronic mutation, c.2257-5G>A, in intron 20 of OCRL in an older brother with atypical Lowe syndrome without eye involvement and a younger brother with renal phenotype alone. This mutation created a splice acceptor motif that was accompanied by a cryptic premature termination codon at the junction of exons 20 and 21. The mutation caused incomplete alternative splicing, which created a small amount of wild-type transcript and a relatively large amount of alternatively spliced transcript with a premature termination codon. In the patients' cells, the alternatively spliced transcript was degraded by nonsense-mediated decay and the wild-type transcript was significantly decreased, but not completely depleted. These findings imply that an intronic mutation creating an incomplete alternative splicing acceptor site results in a relatively low level of wild-type OCRL mRNA expression, leading to partial phenotypes of Lowe syndrome.
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12
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Sun J, Zhou Z, Weng C, Wang C, Chen J, Feng X, Yu P, Qi M. Identification and functional characterization of a hemizygous novel intronic variant in OCRL gene causes Lowe syndrome. Clin Exp Nephrol 2020; 24:657-665. [PMID: 32394213 DOI: 10.1007/s10157-020-01897-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 04/23/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND Lowe syndrome is an X-linked multisystem disorder affecting eyes, nervous system, and kidney. The main causes are mutations in the OCRL gene that encodes a member of the inositol polyphosphate-5-phosphatase protein family. In this study, we aimed to gain new insights into the consequences of a novel OCRL intronic variant on pre-mRNA splicing as a main cause of Lowe syndrome in a boy. METHODS After clinical diagnosis of the patient with Lowe syndrome, genetic testing was used to detect the presence of the OCRL variants. In silico analysis, human splicing finder and PyMol were used to predict this variant effect. Then, we analyzed the variant transcript by using a minigene construct in addition to in silico analysis. RESULTS A hemizygous novel splicing variant in the intron 10 splice donor site of OCRL (c.939 + 3A > C) was identified in a boy with Lowe syndrome. We detected that the splice junction variant leads to aberrant OCRL mRNA splicing which results in the formation of an alternative transcript in which 29 nucleotides of exon 10 were skipped. The findings obtained from the exon-trapping assay were identical to those of in silico analysis. Hence, the truncated OCRL protein may lacked the last 597 native amino acids. CONCLUSIONS The minigene assays detected the same transcript abnormality to in silico assay and were reliable in revealing the pathogenicity of the intronic variant we have used previously. Overall, this study provides new insights about Lowe syndrome and further reveals the molecular pathogenicity mechanism of the intronic variant disease.
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Affiliation(s)
- Junhui Sun
- Department of Cell Biology and Medical Genetics, School of Medicine, Zhejiang University, Research Building A713, Yuhangtang Road 866, Hangzhou, China.,Zhejiang California International Nanosystems Institute, Zhjiang University, Hangzhou, China
| | - Zhongwei Zhou
- Department of Cell Biology and Medical Genetics, School of Medicine, Zhejiang University, Research Building A713, Yuhangtang Road 866, Hangzhou, China
| | - Chen Weng
- Department of Cell Biology and Medical Genetics, School of Medicine, Zhejiang University, Research Building A713, Yuhangtang Road 866, Hangzhou, China
| | - Chaojun Wang
- Department of Urology, The First Affiliated Hospital of Zhejiang University, Hangzhou, China
| | - Jiao Chen
- Department of Cell Biology and Medical Genetics, School of Medicine, Zhejiang University, Research Building A713, Yuhangtang Road 866, Hangzhou, China
| | - Xue Feng
- Department of Cell Biology and Medical Genetics, School of Medicine, Zhejiang University, Research Building A713, Yuhangtang Road 866, Hangzhou, China
| | - Ping Yu
- Department of Cell Biology and Medical Genetics, School of Medicine, Zhejiang University, Research Building A713, Yuhangtang Road 866, Hangzhou, China
| | - Ming Qi
- Department of Cell Biology and Medical Genetics, School of Medicine, Zhejiang University, Research Building A713, Yuhangtang Road 866, Hangzhou, China. .,Zhejiang California International Nanosystems Institute, Zhjiang University, Hangzhou, China. .,Center for Genetic and Genomic Medicine First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China. .,Department of Pathology and Laboratory of Medicine, University of Rochester Medical Centre, Rochester, NY, USA. .,DIAN Diagnostics, Hangzhou, China.
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Liu H, Barnes J, Pedrosa E, Herman NS, Salas F, Wang P, Zheng D, Lachman HM. Transcriptome analysis of neural progenitor cells derived from Lowe syndrome induced pluripotent stem cells: identification of candidate genes for the neurodevelopmental and eye manifestations. J Neurodev Disord 2020; 12:14. [PMID: 32393163 PMCID: PMC7212686 DOI: 10.1186/s11689-020-09317-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 04/28/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Lowe syndrome (LS) is caused by loss-of-function mutations in the X-linked gene OCRL, which codes for an inositol polyphosphate 5-phosphatase that plays a key role in endosome recycling, clathrin-coated pit formation, and actin polymerization. It is characterized by congenital cataracts, intellectual and developmental disability, and renal proximal tubular dysfunction. Patients are also at high risk for developing glaucoma and seizures. We recently developed induced pluripotent stem cell (iPSC) lines from three patients with LS who have hypomorphic variants affecting the 3' end of the gene, and their neurotypical brothers to serve as controls. METHODS In this study, we used RNA sequencing (RNA-seq) to obtain transcriptome profiles in LS and control neural progenitor cells (NPCs). RESULTS In a comparison of the patient and control NPCs (n = 3), we found 16 differentially expressed genes (DEGs) at the multiple test adjusted p value (padj) < 0.1, with nine at padj < 0.05. Using nominal p value < 0.05, 319 DEGs were detected. The relatively small number of DEGs could be due to the fact that OCRL is not a transcription factor per se, although it could have secondary effects on gene expression through several different mechanisms. Although the number of DEGs passing multiple test correction was small, those that were found are quite consistent with some of the known molecular effects of OCRL protein, and the clinical manifestations of LS. Furthermore, using gene set enrichment analysis (GSEA), we found that genes increased expression in the patient NPCs showed enrichments of several gene ontology (GO) terms (false discovery rate < 0.25): telencephalon development, pallium development, NPC proliferation, and cortex development, which are consistent with a condition characterized by intellectual disabilities and psychiatric manifestations. In addition, a significant enrichment among the nominal DEGs for genes implicated in autism spectrum disorder (ASD) was found (e.g., AFF2, DNER, DPP6, DPP10, RELN, CACNA1C), as well as several that are strong candidate genes for the development of eye problems found in LS, including glaucoma. The most notable example is EFEMP1, a well-known candidate gene for glaucoma and other eye pathologies. CONCLUSION Overall, the RNA-seq findings present several candidate genes that could help explain the underlying basis for the neurodevelopmental and eye problems seen in boys with LS.
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Affiliation(s)
- Hequn Liu
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Jesse Barnes
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Erika Pedrosa
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Nathaniel S. Herman
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Franklin Salas
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Ping Wang
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Deyou Zheng
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York, USA
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
- Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Herbert M. Lachman
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York, USA
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York, USA
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
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David S, De Waele K, De Wilde B, Faes F, Vanakker O, Walraedt S, Prytuła A. Hypotonia and delayed motor development as an early presentation of Lowe syndrome: case report and literature review. Acta Clin Belg 2019; 74:460-464. [PMID: 30501482 DOI: 10.1080/17843286.2018.1551743] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We describe a boy who presented with neonatal hypotonia, followed by delayed motor development and growth impairment. Further evaluation revealed rickets caused by proximal renal tubular dysfunction. At age 3, the boy exhibited dysmorphic features and bilateral cataract. Genetic analysis of the OCRL gene showed a novel variant in exon 13: c.1250T>A, p.Val417Asp; in silico and segregation analysis confirmed the variant to be pathogenic, compatible with the diagnosis of the oculocerebrorenal syndrome of Lowe. Lowe syndrome is a rare multisystemic disorder; the diagnostic triad requires involvement of the eye, central nervous system and the proximal renal tubule. Typical clinical features are congenital cataract, glaucoma, hypotonia, mental and behavioral problems, benign skin lesions, platelet dysfunction and dental abnormalities. Phenotypic features early in life may be nonspecific, which is illustrated by this case with a late manifestation of cataract. Because an early diagnosis can lead to better counseling and treatment, we suggest urinary testing for proteinuria as a part of the evaluation of children with unexplained hypotonia.
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Affiliation(s)
- Sara David
- Department of Pediatrics, Division of Pediatric Nephrology and Rheumatology, Ghent University Hospital, Ghent, Belgium
| | - Kathleen De Waele
- Department of Pediatrics, Division of Pediatric Endocrinology and Diabetology, Ghent University Hospital, Ghent, Belgium
| | - Bram De Wilde
- Department of Pediatrics, Division of Pediatric Hemato-oncology and Stem Cell Transplantation, Ghent University Hospital, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Franny Faes
- Department of Pediatrics, Division of Pediatric Neurology and Metabolic Disease, Ghent University Hospital, Ghent, Belgium
| | - Olivier Vanakker
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Sophie Walraedt
- Department of Ophtalmology, Ghent University Hospital, Ghent, Belgium
| | - Agnieszka Prytuła
- Department of Pediatrics, Division of Pediatric Nephrology and Rheumatology, Ghent University Hospital, Ghent, Belgium
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Zheng B, Chen Q, Wang C, Zhou W, Chen Y, Ding G, Jia Z, Zhang A, Huang S. Whole-genome sequencing revealed an interstitial deletion encompassing OCRL and SMARCA1 gene in a patient with Lowe syndrome. Mol Genet Genomic Med 2019; 7:e876. [PMID: 31376231 PMCID: PMC6732312 DOI: 10.1002/mgg3.876] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 06/19/2019] [Accepted: 07/01/2019] [Indexed: 12/13/2022] Open
Abstract
Background Lowe syndrome is a rare X‑linked syndrome that is characterized by involvement of the eyes, central nervous system, and kidneys. The aim of the present study was to determine the molecular basis of four patients with congenital cataract, infantile congenital hypotonia, and proximal renal tubular defect. Methods Four children who met the clinical manifestations of Lowe syndrome were enrolled in this study. Patients’ clinical information on eyes, central nervous system, kidneys, and family histories, etc., were reviewed and analyzed. After obtaining informed consent, we performed a mutation analysis of OCRL gene using direct sequencing. Because of failure of PCR amplification, low coverage shortread whole genome sequencing (CNVseq) analysis was performed on one proband. Real‐time PCR was subsequently performed to confirm the CNV that was detected from the CNVseq results. Results We identified three OCRL allelic variants, including two novel missense mutations (c.1423C>T/p.Pro475Ser, c.1502T>G/p.Ile501Ser) and one recurrent nonsense mutation (c.2464C>T/p.Arg822Ter). Various bioinformatic tools revealed scores associated with potential pathogenic effects for the two missense variants, and protein alignments revealed that both variants affected an amino acid highly conserved among species. Since deletion of the entire gene was suspected in a patient, CNVseq was used, identifying an interstitial deletion to approximately 190 kb, encompassing OCRL, and SMARCA1 gene. Moreover, the hemizygous CNV was confirmed by qPCR. Reviewing another case reported in the literature, we found that the deletion of OCRL and nearby genes may contribute to a more severe phenotype and premature death. Conclusions This is the first report of an interstitial deletion encompassing OCRL and SMARCA1 gene in Lowe syndrome. Our results expand the spectrum of mutations of the OCRL gene in Chinese population. Moreover, whole‐genome sequencing presents a comprehensive and reliable approach for detecting genomic copy number variation in patients or carriers in the family with rare inherited disorders.
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Affiliation(s)
- Bixia Zheng
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Qiuxia Chen
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Chunli Wang
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Wei Zhou
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Ying Chen
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Guixia Ding
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Zhanjun Jia
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Aihua Zhang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
| | - SongMing Huang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
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Zaniew M, Bökenkamp A, Kolbuc M, La Scola C, Baronio F, Niemirska A, Szczepanska M, Bürger J, La Manna A, Miklaszewska M, Rogowska-Kalisz A, Gellermann J, Zampetoglou A, Wasilewska A, Roszak M, Moczko J, Krzemien A, Runowski D, Siten G, Zaluska-Lesniewska I, Fonduli P, Zurrida F, Paglialonga F, Gucev Z, Paripovic D, Rus R, Said-Conti V, Sartz L, Chung WY, Park SJ, Lee JW, Park YH, Ahn YH, Sikora P, Stefanidis CJ, Tasic V, Konrad M, Anglani F, Addis M, Cheong HI, Ludwig M, Bockenhauer D. Long-term renal outcome in children with OCRL mutations: retrospective analysis of a large international cohort. Nephrol Dial Transplant 2018; 33:85-94. [PMID: 27708066 DOI: 10.1093/ndt/gfw350] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/25/2016] [Indexed: 12/19/2022] Open
Abstract
Background Lowe syndrome (LS) and Dent-2 disease (DD2) are disorders associated with mutations in the OCRL gene and characterized by progressive chronic kidney disease (CKD). Here, we aimed to investigate the long-term renal outcome and identify potential determinants of CKD and its progression in children with these tubulopathies. Methods Retrospective analyses were conducted of clinical and genetic data in a cohort of 106 boys (LS: 88 and DD2: 18). For genotype-phenotype analysis, we grouped mutations according to their type and localization. To investigate progression of CKD we used survival analysis by Kaplan-Meier method using stage 3 CKD as the end-point. Results Median estimated glomerular filtration rate (eGFR) was lower in the LS group compared with DD2 (58.8 versus 87.4 mL/min/1.73 m2, P < 0.01). CKD stage II-V was found in 82% of patients, of these 58% and 28% had moderate-to-severe CKD in LS and DD2, respectively. Three patients (3%), all with LS, developed stage 5 of CKD. Survival analysis showed that LS was also associated with a faster CKD progression than DD2 (P < 0.01). On multivariate analysis, eGFR was dependent only on age (b = -0.46, P < 0.001). Localization, but not type of mutations, tended to correlate with eGFR. There was also no significant association between presence of nephrocalcinosis, hypercalciuria, proteinuria and number of adverse clinical events and CKD. Conclusions CKD is commonly found in children with OCRL mutations. CKD progression was strongly related to the underlying diagnosis but did not associate with clinical parameters, such as nephrocalcinosis or proteinuria.
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Affiliation(s)
- Marcin Zaniew
- Children's Hospital, Poznan, Poland.,Polish Registry of Inherited Tubulopathies (POLtube), Polish Society of Pediatric Nephrology, Poland
| | - Arend Bökenkamp
- Department of Pediatrics, VU Medical Center, Amsterdam, The Netherlands
| | | | - Claudio La Scola
- Nephrology and Dialysis Unit, Department of Woman, Child and Urological Diseases, Azienda Ospedaliero-Universitaria 'Sant'Orsola-Malpighi', Bologna, Italy
| | - Federico Baronio
- Endocrinology Unit, Department of Woman, Child and Urological Diseases, Azienda Ospedaliero-Universitaria 'Sant'Orsola-Malpighi', Bologna, Italy
| | - Anna Niemirska
- Department of Nephrology, Kidney Transplantation and Hypertension, The Children's Memorial Health Institute, Warsaw, Poland
| | - Maria Szczepanska
- Chair and Clinical Department of Pediatrics, SMDZ in Zabrze, SUM in Katowice, Katowice, Poland
| | - Julia Bürger
- Department of General Pediatrics, University Children's Hospital, Münster, Germany
| | - Angela La Manna
- Department of Pediatrics, II University of Naples, Naples, Italy
| | - Monika Miklaszewska
- Department of Pediatric Nephrology, Collegium Medicum of the Jagiellonian University, Cracow, Poland
| | - Anna Rogowska-Kalisz
- Department of Pediatrics, Immunology and Nephrology, Polish Mothers Memorial Hospital Research Institute, Lódz, Poland
| | - Jutta Gellermann
- Department of Pediatric Nephrology, Charité Universitätsmedizin Berlin, Charité Children's Hospital, Berlin, Germany
| | | | - Anna Wasilewska
- Department of Pediatrics and Nephrology, Medical University of Bialystok, Bialystok, Poland
| | - Magdalena Roszak
- Department of Computer Science and Statistics, Poznan University of Medical Sciences, Poznan, Poland
| | - Jerzy Moczko
- Department of Computer Science and Statistics, Poznan University of Medical Sciences, Poznan, Poland
| | | | - Dariusz Runowski
- Department of Nephrology, Kidney Transplantation and Hypertension, The Children's Memorial Health Institute, Warsaw, Poland
| | | | - Iga Zaluska-Lesniewska
- Department of Pediatrics, Medical University of Gdansk, Nephrology and Hypertension, Gdansk, Poland
| | | | - Franca Zurrida
- Pediatric Nephrology, Hospital G.Brotzu, Cagliari, Italy
| | - Fabio Paglialonga
- Pediatric Nephrology and Dialysis Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Zoran Gucev
- University Children's Hospital, Medical Faculty Skopje, Skopje, Macedonia
| | - Dusan Paripovic
- Nephrology Department, University Children's Hospital, Belgrade, Serbia
| | - Rina Rus
- Division of Nephrology, University Children's Hospital, Ljubljana, Slovenia
| | | | - Lisa Sartz
- Department of Pediatric and Adolescent Medicine, Skåne University Hospital, Lund, Sweden
| | - Woo Yeong Chung
- Department of Pediatrics, Inje University Busan Paik Hospital, Busan, Korea
| | - Se Jin Park
- Department of Pediatrics, Ajou University Daewoo Hospital, Geoje, Korea
| | - Jung Won Lee
- Department of Pediatrics, Ehwa University Mokdong Hospital, Seoul, Korea
| | - Yong Hoon Park
- Department of Pediatrics, Yeungnam University College of Medicine, Daegu, Korea
| | - Yo Han Ahn
- Department of Pediatrics, Hallym University Kangnam Sacred Heart Hospital, Seoul, Korea
| | - Przemyslaw Sikora
- Polish Registry of Inherited Tubulopathies (POLtube), Polish Society of Pediatric Nephrology, Poland.,Department of Pediatric Nephrology, Medical University of Lublin, Lublin, Poland
| | | | - Velibor Tasic
- University Children's Hospital, Medical Faculty Skopje, Skopje, Macedonia
| | - Martin Konrad
- Department of General Pediatrics, University Children's Hospital, Münster, Germany
| | - Franca Anglani
- Laboratory of Histomorphology and Molecular Biology of the Kidney, Department of Medicine, University of Padova, Padova, Italy
| | - Maria Addis
- Department of Public Health, Clinical and Molecular Medicine, University of Cagliari, Cagliari, Italy
| | - Hae Il Cheong
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
| | - Michael Ludwig
- Department of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Detlef Bockenhauer
- University College London, Institute of Child Health and Great Ormond Street Hospital for Children, National Health Service Trust, London, UK
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Barnes J, Salas F, Mokhtari R, Dolstra H, Pedrosa E, Lachman HM. Modeling the neuropsychiatric manifestations of Lowe syndrome using induced pluripotent stem cells: defective F-actin polymerization and WAVE-1 expression in neuronal cells. Mol Autism 2018; 9:44. [PMID: 30147856 PMCID: PMC6094927 DOI: 10.1186/s13229-018-0227-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 07/29/2018] [Indexed: 12/12/2022] Open
Abstract
Background Lowe syndrome (LS) is a rare genetic disorder caused by loss of function mutations in the X-linked gene, OCRL, which codes for inositol polyphosphate 5-phosphatase. LS is characterized by the triad of congenital cataracts, neurodevelopmental impairment (primarily intellectual and developmental disabilities [IDD]), and renal proximal tubular dysfunction. Studies carried out over the years have shown that hypomorphic mutations in OCRL adversely affect endosome recycling and actin polymerization in kidney cells and patient-derived fibroblasts. The renal problem has been traced to an impaired recycling of megalin, a multi-ligand receptor that plays a key role in the reuptake of lipoproteins, amino acids, vitamin-binding proteins, and hormones. However, the neurodevelopmental aspects of the disorder have been difficult to study because the mouse knockout (KO) model does not display LS-related phenotypes. Fortunately, the discovery of induced pluripotent stem (iPS) cells has provided an opportunity to grow patient-specific neurons, which can be used to model neurodevelopmental disorders in vitro, as demonstrated in the many studies that have been published in the past few years in autism spectrum disorders (ASD), schizophrenia (SZ), bipolar disorder (BD), and IDD. Methods We now report the first findings in neurons and neural progenitor cells (NPCs) generated from iPS cells derived from patients with LS and their typically developing male siblings, as well as an isogenic line in which the OCRL gene has been incapacitated by a null mutation generated using CRISPR-Cas9 gene editing. Results We show that neuronal cells derived from patient-specific iPS cells containing hypomorphic variants are deficient in their capacity to produce F-filamentous actin (F-actin) fibers. Abnormalities were also found in the expression of WAVE-1, a component of the WAVE regulatory complex (WRC) that regulates actin polymerization. Curiously, neuronal cells carrying the engineered OCRL null mutation, in which OCRL protein is not expressed, did not show similar defects in F-actin and WAVE-1 expression. This is similar to the apparent lack of a phenotype in the mouse Ocrl KO model, and suggests that in the complete absence of OCRL protein, as opposed to producing a dysfunctional protein, as seen with the hypomorphic variants, there is partial compensation for the F-actin/WAVE-1 regulating function of OCRL. Conclusions Alterations in F-actin polymerization and WRC have been found in a number of genetic subgroups of IDD and ASD. Thus, LS, a very rare genetic condition, is linked to a more expansive family of genes responsible for neurodevelopmental disorders that have shared pathogenic features. Electronic supplementary material The online version of this article (10.1186/s13229-018-0227-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jesse Barnes
- 1Department of Genetics, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Franklin Salas
- 2Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Ryan Mokhtari
- 3Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Hedwig Dolstra
- 4Swammerdam Institute of Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Erika Pedrosa
- 2Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Herbert M Lachman
- 1Department of Genetics, Albert Einstein College of Medicine, Bronx, New York, USA.,2Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York, USA.,5Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA.,6Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
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RD-Connect, NeurOmics and EURenOmics: collaborative European initiative for rare diseases. Eur J Hum Genet 2018; 26:778-785. [PMID: 29487416 PMCID: PMC5974013 DOI: 10.1038/s41431-018-0115-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/21/2017] [Accepted: 01/24/2018] [Indexed: 12/23/2022] Open
Abstract
Although individually uncommon, rare diseases (RDs) collectively affect 6–8% of the population. The unmet need of the rare disease community was recognized by the European Commission which in 2012 funded three flagship projects, RD-Connect, NeurOmics, and EURenOmics, to help move the field forward with the ambition of advancing -omics research and data sharing at their core in line with the goals of IRDiRC (International Rare Disease Research Consortium). NeurOmics and EURenOmics generate -omics data and improve diagnosis and therapy in rare renal and neurological diseases, with RD-Connect developing an infrastructure to facilitate the sharing, systematic integration and analysis of these data. Here, we summarize the achievements of these three projects, their impact on the RD community and their vision for the future. We also report from the Joint Outreach Day organized by the three projects on the 3rd of May 2017 in Berlin. The workshop stimulated an open, multi-stakeholder discussion on the challenges of the rare diseases, and highlighted the cross-project cooperation and the common goal: the use of innovative genomic technologies in rare disease research.
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19
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Hsieh WC, Ramadesikan S, Fekete D, Aguilar RC. Kidney-differentiated cells derived from Lowe Syndrome patient's iPSCs show ciliogenesis defects and Six2 retention at the Golgi complex. PLoS One 2018; 13:e0192635. [PMID: 29444177 PMCID: PMC5812626 DOI: 10.1371/journal.pone.0192635] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 01/26/2018] [Indexed: 12/11/2022] Open
Abstract
Lowe syndrome is an X-linked condition characterized by congenital cataracts, neurological abnormalities and kidney malfunction. This lethal disease is caused by mutations in the OCRL1 gene, which encodes for the phosphatidylinositol 5-phosphatase Ocrl1. While in the past decade we witnessed substantial progress in the identification and characterization of LS patient cellular phenotypes, many of these studies have been performed in knocked-down cell lines or patient's cells from accessible cell types such as skin fibroblasts, and not from the organs affected. This is partially due to the limited accessibility of patient cells from eyes, brain and kidneys. Here we report the preparation of induced pluripotent stem cells (iPSCs) from patient skin fibroblasts and their reprogramming into kidney cells. These reprogrammed kidney cells displayed primary cilia assembly defects similar to those described previously in cell lines. Additionally, the transcription factor and cap mesenchyme marker Six2 was substantially retained in the Golgi complex and the functional nuclear-localized fraction was reduced. These results were confirmed using different batches of differentiated cells from different iPSC colonies and by the use of the human proximal tubule kidney cell line HK2. Indeed, OCRL1 KO led to both ciliogenesis defects and Six2 retention in the Golgi complex. In agreement with Six2's role in the suppression of ductal kidney lineages, cells from this pedigree were over-represented among patient kidney-reprogrammed cells. We speculate that this diminished efficacy to produce cap mesenchyme cells would cause LS patients to have difficulties in replenishing senescent or damaged cells derived from this lineage, particularly proximal tubule cells, leading to pathological scenarios such as tubular atrophy.
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Affiliation(s)
- Wen-Chieh Hsieh
- Department of Biological Sciences, Purdue University, West Lafayette, IN United States of America
| | - Swetha Ramadesikan
- Department of Biological Sciences, Purdue University, West Lafayette, IN United States of America
| | - Donna Fekete
- Department of Biological Sciences, Purdue University, West Lafayette, IN United States of America
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN United States of America
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN United States of America
- Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN United States of America
| | - Ruben Claudio Aguilar
- Department of Biological Sciences, Purdue University, West Lafayette, IN United States of America
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN United States of America
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN United States of America
- Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN United States of America
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20
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Splicing Analysis of Exonic OCRL Mutations Causing Lowe Syndrome or Dent-2 Disease. Genes (Basel) 2018; 9:genes9010015. [PMID: 29300302 PMCID: PMC5793168 DOI: 10.3390/genes9010015] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/11/2017] [Accepted: 12/27/2017] [Indexed: 01/12/2023] Open
Abstract
Mutations in the OCRL gene are associated with both Lowe syndrome and Dent-2 disease. Patients with Lowe syndrome present congenital cataracts, mental disabilities and a renal proximal tubulopathy, whereas patients with Dent-2 disease exhibit similar proximal tubule dysfunction but only mild, or no additional clinical defects. It is not yet understood why some OCRL mutations cause the phenotype of Lowe syndrome, while others develop the milder phenotype of Dent-2 disease. Our goal was to gain new insights into the consequences of OCRL exonic mutations on pre-mRNA splicing. Using predictive bioinformatics tools, we selected thirteen missense mutations and one synonymous mutation based on their potential effects on splicing regulatory elements or splice sites. These mutations were analyzed in a minigene splicing assay. Results of the RNA analysis showed that three presumed missense mutations caused alterations in pre-mRNA splicing. Mutation c.741G>T; p.(Trp247Cys) generated splicing silencer sequences and disrupted splicing enhancer motifs that resulted in skipping of exon 9, while mutations c.2581G>A; p.(Ala861Thr) and c.2581G>C; p.(Ala861Pro) abolished a 5′ splice site leading to skipping of exon 23. Mutation c.741G>T represents the first OCRL exonic variant outside the conserved splice site dinucleotides that results in alteration of pre-mRNA splicing. Our results highlight the importance of evaluating the effects of OCRL exonic mutations at the mRNA level.
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21
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Weigert A, Hoppe B. Nephrolithiasis and Nephrocalcinosis in Childhood-Risk Factor-Related Current and Future Treatment Options. Front Pediatr 2018; 6:98. [PMID: 29707529 PMCID: PMC5906718 DOI: 10.3389/fped.2018.00098] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 03/26/2018] [Indexed: 12/19/2022] Open
Abstract
Nephrolithiasis, urolithiasis, and nephrocalcinosis (NC) have become common causes of hospitalization and referral to pediatric outpatient clinics. It is of utmost importance to start with diagnostic evaluation directly after the first passage of a kidney stone, or if NC is diagnosed, in each pediatric patient. This is necessary, as in about 80% of children a metabolic reason for stone disease is detected. Current treatment options are scarce and mainly include general measures like an increased fluid intake or elevating the solubility of a lithogenic substance. According to the given lithogenic risk factor(s), specific treatment options are available and are being summarized in this review. Furthermore, an outlook on potential future treatment options, including innovative strategies such as mRNA-based or recombinant enzyme substitution therapy, is given.
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Affiliation(s)
- Alexander Weigert
- Division of Pediatric Nephrology, Department of Pediatrics, University Children's Hospital, Bonn, Germany
| | - Bernd Hoppe
- Division of Pediatric Nephrology, Department of Pediatrics, University Children's Hospital, Bonn, Germany
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22
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Abdalla E, El‐Beheiry A, Dieterich K, Thevenon J, Fauré J, Rendu J. “Lowe syndrome: A particularly severe phenotype without clinical kidney involvement”. Am J Med Genet A 2017; 176:460-464. [DOI: 10.1002/ajmg.a.38572] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 11/02/2017] [Accepted: 11/13/2017] [Indexed: 01/22/2023]
Affiliation(s)
- Ebtesam Abdalla
- Department of Human GeneticsMedical Research InstituteAlexandria UniversityAlexandriaEgypt
| | - Ahmed El‐Beheiry
- Department of RadiologyAlexandria Faculty of MedicineAlexandria UniversityAlexandriaEgypt
| | - Klaus Dieterich
- Département de Génétique et ProcréationCHU Grenoble AlpesUniversité Grenoble AlpesGrenobleFrance
| | - Julien Thevenon
- Département de Génétique et ProcréationCHU Grenoble AlpesUniversité Grenoble AlpesGrenobleFrance
| | - Julien Fauré
- Département de Biochimie Pharmacologie ToxicologieBiochimie et Génétique MoléculaireCentre Hospitalier Universitaire Grenoble AlpesUniversité Grenoble AlpesGrenobleFrance
- Grenoble Institut des NeurosciencesInserm U1216–Eq. 4 C‐MyPathLaTroncheFrance
| | - John Rendu
- Département de Biochimie Pharmacologie ToxicologieBiochimie et Génétique MoléculaireCentre Hospitalier Universitaire Grenoble AlpesUniversité Grenoble AlpesGrenobleFrance
- Grenoble Institut des NeurosciencesInserm U1216–Eq. 4 C‐MyPathLaTroncheFrance
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23
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Zaniew M, Mizerska-Wasiak M, Załuska-Leśniewska I, Adamczyk P, Kiliś-Pstrusińska K, Haliński A, Zawadzki J, Lipska-Ziętkiewicz BS, Pawlaczyk K, Sikora P, Ludwig M, Szczepańska M. Dent disease in Poland: what we have learned so far? Int Urol Nephrol 2017; 49:2005-2017. [PMID: 28815356 DOI: 10.1007/s11255-017-1676-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 08/07/2017] [Indexed: 12/13/2022]
Abstract
PURPOSE Dent disease (DD) is a rare tubulopathy characterized by proximal tubular dysfunction leading to chronic kidney disease (CKD). The aim of the study was to characterize patients with DD in Poland. METHODS A retrospective analysis of a national cohort with genetically confirmed diagnosis. RESULTS Of 24 males, all patients except one carried mutations in the CLCN5 gene; in one patient a mutation in the OCRL gene was disclosed. Molecular diagnosis was delayed 1 year on average (range 0-21 years). The most common features were tubular proteinuria (100%), hypercalciuria (87%), and nephrocalcinosis (56%). CKD (≤stage II) and growth deficiency were found in 45 and 22% of patients, respectively. Over time, a progression of CKD and persistence of growth impairment was noted. Subnephrotic and nephrotic proteinuria (20%) was found in most patients, but tubular proteinuria was assessed in only 67% of patients. In one family steroid-resistant nephrotic syndrome prompted a genetic testing, and reverse phenotyping. Five children (20%) underwent kidney biopsy, and two of them were treated with immunosuppressants. Hydrochlorothiazide and angiotensin-converting enzyme inhibitors were prescribed for a significant proportion of patients (42 and 37.5%, respectively), while supplemental therapy with phosphate, potassium, vitamin D (12.5% each), and alkali (4.2%) was insufficient, when compared to the percentages of patients requiring repletion. CONCLUSIONS We found CLCN5 mutations in the vast majority of Polish patients with DD. Proteinuria was the most constant finding; however, tubular proteins were not assessed commonly, likely leading to delayed molecular diagnosis and misdiagnosis in some patients. More consideration should be given to optimize the therapy.
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Affiliation(s)
- Marcin Zaniew
- Children's Hospital, ul. Krysiewicza 7/8, 61-825, Poznan, Poland. .,Polish Registry of Inherited Tubulopathies (POLtube), Polish Society of Pediatric Nephrology, Poznan, Poland.
| | | | - Iga Załuska-Leśniewska
- Department of Pediatrics, Nephrology and Hypertension, Medical University of Gdańsk, Gdańsk, Poland
| | - Piotr Adamczyk
- Department and Clinics of Pediatrics, SMDZ, Medical University of Silesia in Katowice, Zabrze, Poland
| | | | - Adam Haliński
- Department of Urology, Regional Hospital, Nowa Sól, Poland
| | - Jan Zawadzki
- Department of Nephrology and Kidney Transplantation, The Children's Memorial Health Institute, Warsaw, Poland
| | - Beata S Lipska-Ziętkiewicz
- Department of Biology and Medical Genetics, Clinical Genetics Unit, Medical University of Gdańsk, Gdańsk, Poland
| | - Krzysztof Pawlaczyk
- Department of Nephrology, Transplantology and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland
| | - Przemysław Sikora
- Polish Registry of Inherited Tubulopathies (POLtube), Polish Society of Pediatric Nephrology, Poznan, Poland.,Department of Pediatric Nephrology, Medical University of Lublin, Lublin, Poland
| | - Michael Ludwig
- Department of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Maria Szczepańska
- Department and Clinics of Pediatrics, SMDZ, Medical University of Silesia in Katowice, Zabrze, Poland
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24
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Abstract
Lowe syndrome is an X-linked disease that is characterized by congenital cataracts, central hypotonia, intellectual disability and renal Fanconi syndrome. The disease is caused by mutations in OCRL, which encodes an inositol polyphosphate 5-phosphatase (OCRL) that acts on phosphoinositides - quantitatively minor constituents of cell membranes that are nonetheless pivotal regulators of intracellular trafficking. In this Review we summarize the considerable progress made over the past decade in understanding the cellular roles of OCRL in regulating phosphoinositide balance along the endolysosomal pathway, a fundamental system for the reabsorption of proteins and solutes by proximal tubular cells. We discuss how studies of OCRL have led to important discoveries about the basic mechanisms of membrane trafficking and describe the key features and limitations of the currently available animal models of Lowe syndrome. Mutations in OCRL can also give rise to a milder pathology, Dent disease 2, which is characterized by renal Fanconi syndrome in the absence of extrarenal pathologies. Understanding how mutations in OCRL give rise to two clinical entities with differing extrarenal manifestations represents an opportunity to identify molecular pathways that could be targeted to develop treatments for these conditions.
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25
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Ocular Pathology of Oculocerebrorenal Syndrome of Lowe: Novel Mutations and Genotype-Phenotype Analysis. Sci Rep 2017; 7:1442. [PMID: 28473699 PMCID: PMC5431454 DOI: 10.1038/s41598-017-01447-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 03/28/2017] [Indexed: 12/02/2022] Open
Abstract
Mutations in the OCRL1 gene result in the oculocerebrorenal syndrome of Lowe, with symptoms including congenital bilateral cataracts, glaucoma, renal failure, and neurological impairments. OCRL1 encodes an inositol polyphosphate 5-phosphatase which preferentially dephosphorylates phosphatidylinositide 4,5 bisphosphate (PI(4,5)P2). We have identified two novel mutations in two unrelated Lowe syndrome patients with congenital glaucoma. Novel deletion mutations are detected at c.739-742delAAAG in Lowe patient 1 and c.1595-1631del in Lowe patient 2. End stage glaucoma in patient 2 resulted in the enucleation of the eye, which on histology demonstrated corneal keloid, fibrous infiltration of the angle, ectropion uvea, retinal gliosis, and retinal ganglion cell loss. We measured OCRL protein levels in patient keratinocytes and found that Lowe 1 patient cells had significantly reduced OCRL protein as compared to the control keratinocytes. Genotype-phenotype correlation of OCRL1 mutations associated with congenital glaucoma revealed clustering of missense and deletion mutations in the 5-phosphatase domain and the RhoGAP-like domain. In conclusion, we report novel OCRL1 mutations in Lowe syndrome patients and the corresponding histopathologic analysis of one patient’s ocular pathology.
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26
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Klootwijk E, Dufek S, Issler N, Bockenhauer D, Kleta R. Pathophysiology, current treatments and future targets in hereditary forms of renal Fanconi syndrome. Expert Opin Orphan Drugs 2016. [DOI: 10.1080/21678707.2017.1259560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
| | - Stephanie Dufek
- Centre for Nephrology, University College London, London, UK
| | - Naomi Issler
- Centre for Nephrology, University College London, London, UK
| | | | - Robert Kleta
- Centre for Nephrology, University College London, London, UK
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27
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Rendu J, Montjean R, Coutton C, Suri M, Chicanne G, Petiot A, Brocard J, Grunwald D, Pietri Rouxel F, Payrastre B, Lunardi J, Dorseuil O, Marty I, Fauré J. Functional Characterization and Rescue of a Deep Intronic Mutation in OCRL Gene Responsible for Lowe Syndrome. Hum Mutat 2016; 38:152-159. [PMID: 27790796 DOI: 10.1002/humu.23139] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 10/13/2016] [Indexed: 12/31/2022]
Abstract
Dent-2 disease and Lowe syndrome are two pathologies caused by mutations in inositol polyphosphate 5-phosphatase OCRL gene. Both conditions share proximal tubulopathy evolving to chronic kidney failure. Lowe syndrome is in addition defined by a bilateral congenital cataract, intellectual disability, and hypotonia. The pathology evolves in two decades to a severe condition with renal complications and a fatal issue. We describe here a proof of principle for a targeted gene therapy on a mutation of the OCRL gene that is associated with Lowe syndrome. The affected patient bears a deep intronic mutation inducing a pseudo-exon inclusion in the mRNA, leading to a OCRL-1 protein loss. An exon-skipping strategy was designed to correct the effect of the mutation in cultured cells. We show that a recombinant U7-modified small RNA efficiently triggered the restoration of normal OCRL expression at mRNA and protein levels in patient's fibroblasts. Moreover, the PI(4,5)P2 accumulation and cellular alterations that are hallmark of OCRL-1 dysfunction were also rescued. Altogether, we provide evidence that the restoration of OCRL-1 protein, even at a reduced level, through RNA-based therapy represents a potential therapeutic approach for patients with OCRL splice mutations.
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Affiliation(s)
- John Rendu
- Cellular Myology and Pathology, INSERM, U1216, Grenoble, France.,Grenoble Institut of Neurosciences, Université Grenoble Alpes, France.,Biochimie Génétique et Moléculaire, CHU Grenoble Alpes, France
| | - Rodrick Montjean
- Institut Cochin, INSERM U1016, Paris, France.,CNRS UMR8104, Université Paris Descartes, Paris, France
| | - Charles Coutton
- Laboratoire de Génétique Chromosomique, CHU Grenoble Alpes, France
| | - Mohnish Suri
- Nottingham Clinical Genetics Service, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom
| | - Gaetan Chicanne
- I2MC, INSERM U1048, Toulouse, France.,Laboratoire d'Hématologie, CHU de Toulouse, France
| | - Anne Petiot
- Cellular Myology and Pathology, INSERM, U1216, Grenoble, France.,Grenoble Institut of Neurosciences, Université Grenoble Alpes, France
| | - Julie Brocard
- Cellular Myology and Pathology, INSERM, U1216, Grenoble, France.,Grenoble Institut of Neurosciences, Université Grenoble Alpes, France
| | - Didier Grunwald
- Cellular Myology and Pathology, INSERM, U1216, Grenoble, France.,Grenoble Institut of Neurosciences, Université Grenoble Alpes, France
| | - France Pietri Rouxel
- Research Center of Myology, INSERM UMRS974, Paris, France.,CNRS FRE3617, UPMC, Paris, France
| | - Bernard Payrastre
- I2MC, INSERM U1048, Toulouse, France.,Laboratoire d'Hématologie, CHU de Toulouse, France
| | - Joel Lunardi
- Cellular Myology and Pathology, INSERM, U1216, Grenoble, France.,Grenoble Institut of Neurosciences, Université Grenoble Alpes, France.,Biochimie Génétique et Moléculaire, CHU Grenoble Alpes, France
| | - Olivier Dorseuil
- Institut Cochin, INSERM U1016, Paris, France.,CNRS UMR8104, Université Paris Descartes, Paris, France
| | - Isabelle Marty
- Cellular Myology and Pathology, INSERM, U1216, Grenoble, France.,Grenoble Institut of Neurosciences, Université Grenoble Alpes, France
| | - Julien Fauré
- Cellular Myology and Pathology, INSERM, U1216, Grenoble, France.,Grenoble Institut of Neurosciences, Université Grenoble Alpes, France.,Biochimie Génétique et Moléculaire, CHU Grenoble Alpes, France
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28
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Watanabe M, Nakagawa R, Kohmoto T, Naruto T, Suga KI, Goji A, Horikawa H, Masuda K, Kagami S, Imoto I. Exome-first approach identified a novel gloss deletion associated with Lowe syndrome. Hum Genome Var 2016; 3:16037. [PMID: 27867521 PMCID: PMC5103007 DOI: 10.1038/hgv.2016.37] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 09/16/2016] [Accepted: 09/19/2016] [Indexed: 11/09/2022] Open
Abstract
Lowe syndrome (LS) is an X-linked disorder affecting the eyes, nervous system and kidneys, typically caused by missense or nonsense/frameshift OCRL mutations. We report a 6-month-old male clinically suspected to have LS, but without the Fanconi-type renal dysfunction. Using a targeted-exome sequencing-first approach, LS was diagnosed by the identification of a deletion involving 1.7 Mb at Xq25-q26.1, encompassing the entire OCRL gene and neighboring loci.
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Affiliation(s)
- Miki Watanabe
- Department of Human Genetics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Ryuji Nakagawa
- Department of Paediatrics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Tomohiro Kohmoto
- Department of Human Genetics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Takuya Naruto
- Department of Human Genetics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Ken-ichi Suga
- Department of Paediatrics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Aya Goji
- Department of Paediatrics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Hideaki Horikawa
- Department of Human Genetics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
- Support Center for Advanced Medical Sciences, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Kiyoshi Masuda
- Department of Human Genetics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Shoji Kagami
- Department of Paediatrics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Issei Imoto
- Department of Human Genetics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
- Support Center for Advanced Medical Sciences, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
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29
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Abstract
The oculocerebrorenal syndrome of Lowe is a rare X-linked multisystemic disorder characterized by the triad of congenital cataracts, intellectual disability, and proximal renal tubular dysfunction. Whereas the ocular manifestations and severe muscular hypotonia are the typical first diagnostic clues apparent at birth, the manifestations of incomplete renal Fanconi syndrome are often recognized only later in life. Other characteristic features are progressive severe growth retardation and behavioral problems, with tantrums. Many patients develop a debilitating arthropathy. Treatment is symptomatic, and the life span rarely exceeds 40 years. The causative oculocerebrorenal syndrome of Lowe gene (OCRL) encodes the inositol polyphosphate 5-phosphatase OCRL-1. OCRL variants have not only been found in classic Lowe syndrome, but also in patients with a predominantly renal phenotype classified as Dent disease type 2 (Dent-2). Recent data indicate that there is a phenotypic continuum between Dent-2 disease and Lowe syndrome, suggesting that there are individual differences in the ability to compensate for the loss of enzyme function. Extensive research has demonstrated that OCRL-1 is involved in multiple intracellular processes involving endocytic trafficking and actin skeleton dynamics. This explains the multi-organ manifestations of the disease. Still, the mechanisms underlying the wide phenotypic spectrum are poorly understood, and we are far from a causative therapy. In this review, we provide an update on clinical and molecular genetic findings in Lowe syndrome and the cellular and physiological functions of OCRL-1.
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