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Boulogne F, Claus LR, Wiersma H, Oelen R, Schukking F, de Klein N, Li S, Westra HJ, van der Zwaag B, van Reekum F, Sierks D, Schönauer R, Li Z, Bijlsma EK, Bos WJW, Halbritter J, Knoers NVAM, Besse W, Deelen P, Franke L, van Eerde AM. KidneyNetwork: using kidney-derived gene expression data to predict and prioritize novel genes involved in kidney disease. Eur J Hum Genet 2023; 31:1300-1308. [PMID: 36807342 PMCID: PMC10620423 DOI: 10.1038/s41431-023-01296-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 11/24/2022] [Accepted: 01/18/2023] [Indexed: 02/22/2023] Open
Abstract
Genetic testing in patients with suspected hereditary kidney disease may not reveal the genetic cause for the disorder as potentially pathogenic variants can reside in genes that are not yet known to be involved in kidney disease. We have developed KidneyNetwork, that utilizes tissue-specific expression to inform candidate gene prioritization specifically for kidney diseases. KidneyNetwork is a novel method constructed by integrating a kidney RNA-sequencing co-expression network of 878 samples with a multi-tissue network of 31,499 samples. It uses expression patterns and established gene-phenotype associations to predict which genes could be related to what (disease) phenotypes in an unbiased manner. We applied KidneyNetwork to rare variants in exome sequencing data from 13 kidney disease patients without a genetic diagnosis to prioritize candidate genes. KidneyNetwork can accurately predict kidney-specific gene functions and (kidney disease) phenotypes for disease-associated genes. The intersection of prioritized genes with genes carrying rare variants in a patient with kidney and liver cysts identified ALG6 as plausible candidate gene. We strengthen this plausibility by identifying ALG6 variants in several cystic kidney and liver disease cases without alternative genetic explanation. We present KidneyNetwork, a publicly available kidney-specific co-expression network with optimized gene-phenotype predictions for kidney disease phenotypes. We designed an easy-to-use online interface that allows clinicians and researchers to use gene expression and co-regulation data and gene-phenotype connections to accelerate advances in hereditary kidney disease diagnosis and research. TRANSLATIONAL STATEMENT: Genetic testing in patients with suspected hereditary kidney disease may not reveal the genetic cause for the patient's disorder. Potentially pathogenic variants can reside in genes not yet known to be involved in kidney disease, making it difficult to interpret the relevance of these variants. This reveals a clear need for methods to predict the phenotypic consequences of genetic variation in an unbiased manner. Here we describe KidneyNetwork, a tool that utilizes tissue-specific expression to predict kidney-specific gene functions. Applying KidneyNetwork to a group of undiagnosed cases identified ALG6 as a candidate gene in cystic kidney and liver disease. In summary, KidneyNetwork can aid the interpretation of genetic variants and can therefore be of value in translational nephrogenetics and help improve the diagnostic yield in kidney disease patients.
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Affiliation(s)
- Floranne Boulogne
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Oncode Institute, Utrecht, The Netherlands
| | - Laura R Claus
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Henry Wiersma
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Roy Oelen
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Oncode Institute, Utrecht, The Netherlands
| | - Floor Schukking
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Niek de Klein
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Shuang Li
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Genomics Coordination Center, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Harm-Jan Westra
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Oncode Institute, Utrecht, The Netherlands
| | - Bert van der Zwaag
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Franka van Reekum
- Department of Nephrology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Dana Sierks
- Medical Department III - Endocrinology, Nephrology, Rheumatology Department of Internal Medicine, Division of Nephrology, University of Leipzig Medical Center, Leipzig, Germany
| | - Ria Schönauer
- Medical Department III - Endocrinology, Nephrology, Rheumatology Department of Internal Medicine, Division of Nephrology, University of Leipzig Medical Center, Leipzig, Germany
- Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Zhigui Li
- Department of Internal Medicine (Nephrology), Yale School of Medicine, New Haven, CT, USA
| | - Emilia K Bijlsma
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Willem Jan W Bos
- Department of Internal Medicine, St Antonius Hospital, Nieuwegein, The Netherlands
- Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Jan Halbritter
- Medical Department III - Endocrinology, Nephrology, Rheumatology Department of Internal Medicine, Division of Nephrology, University of Leipzig Medical Center, Leipzig, Germany
- Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Nine V A M Knoers
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Whitney Besse
- Department of Internal Medicine (Nephrology), Yale School of Medicine, New Haven, CT, USA
| | - Patrick Deelen
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Oncode Institute, Utrecht, The Netherlands
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Lude Franke
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Oncode Institute, Utrecht, The Netherlands
| | - Albertien M van Eerde
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands.
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Lipiński P, Stępień KM, Ciara E, Tylki-Szymańska A, Jezela-Stanek A. Skeletal and Bone Mineral Density Features, Genetic Profile in Congenital Disorders of Glycosylation: Review. Diagnostics (Basel) 2021; 11:diagnostics11081438. [PMID: 34441372 PMCID: PMC8391432 DOI: 10.3390/diagnostics11081438] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/04/2021] [Accepted: 08/04/2021] [Indexed: 11/25/2022] Open
Abstract
Congenital disorders of glycosylation (CDGs) are a heterogeneous group of disorders with impaired glycosylation of proteins and lipids. These conditions have multisystemic clinical manifestations, resulting in gradually progressive complications including skeletal involvement and reduced bone mineral density. Contrary to PMM2-CDG, all remaining CDG, including ALG12-CDG, ALG3-CDG, ALG9-CDG, ALG6-CDG, PGM3-CDG, CSGALNACT1-CDG, SLC35D1-CDG and TMEM-165, are characterized by well-defined skeletal dysplasia. In some of them, prenatal-onset severe skeletal dysplasia is observed associated with early death. Osteoporosis or osteopenia are frequently observed in all CDG types and are more pronounced in adults. Hormonal dysfunction, limited mobility and inadequate diet are common risk factors for reduced bone mineral density. Skeletal involvement in CDGs is underestimated and, thus, should always be carefully investigated and managed to prevent fractures and chronic pain. With the advent of new therapeutic developments for CDGs, the severity of skeletal complications may be reduced. This review focuses on possible mechanisms of skeletal manifestations, risk factors for osteoporosis, and bone markers in reported paediatric and adult CDG patients.
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Affiliation(s)
- Patryk Lipiński
- Department of Pediatrics, Nutrition and Metabolic Diseases, The Children’s Memorial Health Institute, 04-730 Warsaw, Poland;
- Correspondence:
| | - Karolina M. Stępień
- Adult Inherited Metabolic Diseases, Salford Royal NHS Foundation Trust, Salford M6 8HD, UK;
| | - Elżbieta Ciara
- Department of Medical Genetics, The Children’s Memorial Health Institute, 04-730 Warsaw, Poland;
| | - Anna Tylki-Szymańska
- Department of Pediatrics, Nutrition and Metabolic Diseases, The Children’s Memorial Health Institute, 04-730 Warsaw, Poland;
| | - Aleksandra Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland;
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3
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Morava E, Tiemes V, Thiel C, Seta N, de Lonlay P, de Klerk H, Mulder M, Rubio-Gozalbo E, Visser G, van Hasselt P, Horovitz DDG, de Souza CFM, Schwartz IVD, Green A, Al-Owain M, Uziel G, Sigaudy S, Chabrol B, van Spronsen FJ, Steinert M, Komini E, Wurm D, Bevot A, Ayadi A, Huijben K, Dercksen M, Witters P, Jaeken J, Matthijs G, Lefeber DJ, Wevers RA. ALG6-CDG: a recognizable phenotype with epilepsy, proximal muscle weakness, ataxia and behavioral and limb anomalies. J Inherit Metab Dis 2016; 39:713-723. [PMID: 27287710 DOI: 10.1007/s10545-016-9945-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 03/17/2016] [Accepted: 05/04/2016] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Alpha-1,3-glucosyltransferase congenital disorder of glycosylation (ALG6-CDG) is a congenital disorder of glycosylation. The original patients were described with hypotonia, developmental disability, epilepsy, and increased bleeding tendency. METHODS Based on Euroglycan database registration, we approached referring clinicians and collected comprehensive data on 41 patients. RESULTS We found hypotonia and developmental delay in all ALG6-CDG patients and epilepsy, ataxia, proximal muscle weakness, and, in the majority of cases, failure to thrive. Nine patients developed intractable seizures. Coagulation anomalies were present in <50 % of cases, without spontaneous bleedings. Facial dysmorphism was rare, but seven patients showed missing phalanges and brachydactyly. Cyclic behavioral change, with autistic features and depressive episodes, was one of the most significant complaints. Eleven children died before the age of 4 years due to protein losing enteropathy (PLE), sepsis, or seizures. The oldest patient was a 40 year-old Dutch woman. The most common pathogenic protein alterations were p.A333V and p.I299Del, without any clear genotype-phenotype correlation. DISCUSSION ALG6-CDG has been now described in 89 patients, making it the second most common type of CDG. It has a recognizable phenotype and a primary neurologic presentation.
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Affiliation(s)
- Eva Morava
- Center for Metabolic Diseases, Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium.
- Tulane University Medical School, Hayward Genetics Center, New Orleans, LA, USA.
| | - Vera Tiemes
- Department of Pediatrics, Radboud University Medical Center, Nijmegen, The Netherlands
- Translational Metabolic Laboratory, Department Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Christian Thiel
- Center for Child and Adolescent Medicine, Kinderheilkunde I, University of Heidelberg, Heidelberg, Germany
| | - Nathalie Seta
- Biochimie Métabolique Hôpital Bichat-Claude Bernard, Paris, France
| | - Pascale de Lonlay
- Reference Center of Metabolism, Necker-Enfants Malades Hospital, APHP, Imagine Institute, University Paris-Descartes, Paris, France
| | - Hans de Klerk
- Department of Pediatrics, Erasmus MC - University Medical Center Rotterdam, Emma Hospital, Rotterdam, The Netherlands
| | - Margot Mulder
- Department of Pediatrics, Free University Amsterdam, Amsterdam, The Netherlands
| | - Estela Rubio-Gozalbo
- Department of Pediatrics and Laboratory Genetic Metabolic Diseases, University of Maastricht, Maastricht, The Netherlands
| | - Gepke Visser
- Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Peter van Hasselt
- Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | | | | | - Andrew Green
- National Centre for Medical Genetics, Dublin, Ireland
| | - Mohammed Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | | | - Sabine Sigaudy
- Département de Génétique Médicale, Hôpital Timone Enfant, Marseille, France
| | - Brigitte Chabrol
- Neuropediatrics Unit, Childrens Hospital CHU Timone, Marseille, France
| | - Franc-Jan van Spronsen
- Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center of Groningen, University of Groningen, Groningen, The Netherlands
| | - Martin Steinert
- Sozialpädiatrisches Zentrum, Neuropädiatrie, Klinik für Kinder- und Jugendmedizin, Dortmund, Germany
| | - Eleni Komini
- Kinderklinik Villingen, Schwarzwald-Baar-Klinikum, Villingen, Germany
| | - Donald Wurm
- Department of Pediatrics, Klinikum Saarbrücken, Saarbrücken, Germany
| | - Andrea Bevot
- Department of Pediatric Neurology and Developmental Medicine, Universal Children's Hospital Tübingen, Tübingen, Germany
| | - Addelkarim Ayadi
- Biochimie Métabolique Hôpital Bichat-Claude Bernard, Paris, France
| | - Karin Huijben
- Translational Metabolic Laboratory, Department Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marli Dercksen
- Centre for Human Metabolomics, North-West University, Potchefstroom, South Africa
| | - Peter Witters
- Center for Metabolic Diseases, Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Jaak Jaeken
- Center for Metabolic Diseases, Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Gert Matthijs
- Laboratory for Molecular Diagnosis, Center for Human Genetics, University of Leuven, Leuven, Belgium
| | - Dirk J Lefeber
- Translational Metabolic Laboratory, Department Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Neurology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ron A Wevers
- Translational Metabolic Laboratory, Department Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
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4
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Clinical utility gene card for: ALG6 defective congenital disorder of glycosylation. Eur J Hum Genet 2014; 23:ejhg2014146. [PMID: 25052310 DOI: 10.1038/ejhg.2014.146] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Revised: 06/18/2014] [Accepted: 06/25/2014] [Indexed: 12/29/2022] Open
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5
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PGM3 mutations cause a congenital disorder of glycosylation with severe immunodeficiency and skeletal dysplasia. Am J Hum Genet 2014; 95:96-107. [PMID: 24931394 DOI: 10.1016/j.ajhg.2014.05.007] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 05/16/2014] [Indexed: 12/30/2022] Open
Abstract
Human phosphoglucomutase 3 (PGM3) catalyzes the conversion of N-acetyl-glucosamine (GlcNAc)-6-phosphate into GlcNAc-1-phosphate during the synthesis of uridine diphosphate (UDP)-GlcNAc, a sugar nucleotide critical to multiple glycosylation pathways. We identified three unrelated children with recurrent infections, congenital leukopenia including neutropenia, B and T cell lymphopenia, and progression to bone marrow failure. Whole-exome sequencing demonstrated deleterious mutations in PGM3 in all three subjects, delineating their disease to be due to an unsuspected congenital disorder of glycosylation (CDG). Functional studies of the disease-associated PGM3 variants in E. coli cells demonstrated reduced PGM3 activity for all mutants tested. Two of the three children had skeletal anomalies resembling Desbuquois dysplasia: short stature, brachydactyly, dysmorphic facial features, and intellectual disability. However, these additional features were absent in the third child, showing the clinical variability of the disease. Two children received hematopoietic stem cell transplantation of cord blood and bone marrow from matched related donors; both had successful engraftment and correction of neutropenia and lymphopenia. We define PGM3-CDG as a treatable immunodeficiency, document the power of whole-exome sequencing in gene discoveries for rare disorders, and illustrate the utility of genomic analyses in studying combined and variable phenotypes.
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6
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Scott K, Gadomski T, Kozicz T, Morava E. Congenital disorders of glycosylation: new defects and still counting. J Inherit Metab Dis 2014; 37:609-17. [PMID: 24831587 PMCID: PMC4141334 DOI: 10.1007/s10545-014-9720-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 04/16/2014] [Accepted: 04/22/2014] [Indexed: 12/11/2022]
Abstract
Almost 50 inborn errors of metabolism have been described due to congenital defects in N-linked glycosylation. These phenotypically diverse disorders typically present as clinical syndromes, affecting multiple systems including the central nervous system, muscle function, transport, regulation, immunity, endocrine system, and coagulation. An increasing number of disorders have been discovered using novel techniques that combine glycobiology with next-generation sequencing or use tandem mass spectrometry in combination with molecular gene-hunting techniques. The number of "classic" congenital disorders of glycosylation (CDGs) due to N-linked glycosylation defects is still rising. Eight novel CDGs affecting N-linked glycans were discovered in 2013 alone. Newly discovered genes teach us about the significance of glycosylation in cell-cell interaction, signaling, organ development, cell survival, and mosaicism, in addition to the consequences of abnormal glycosylation for muscle function. We have learned how important glycosylation is in posttranslational modification and how glycosylation defects can imitate recognizable, previously described phenotypes. In many CDG subtypes, patients unexpectedly presented with long-term survival, whereas some others presented with nonsyndromic intellectual disability. In this review, recently discovered N-linked CDGs are described, with a focus on clinical presentations and therapeutic ideas. A diagnostic approach in unsolved N-linked CDG cases with abnormal transferrin screening results is also suggested.
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Affiliation(s)
- Kyle Scott
- Hayward Genetics Center, Tulane University School of Medicine, 1430 Tulane Ave, New Orleans, LA, 70112, USA
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7
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Wolthuis DFGJ, Janssen MC, Cassiman D, Lefeber DJ, Morava E, Morava-Kozicz E. Defining the phenotype and diagnostic considerations in adults with congenital disorders of N-linked glycosylation. Expert Rev Mol Diagn 2014; 14:217-24. [PMID: 24524732 DOI: 10.1586/14737159.2014.890052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Congenital disorders of N-glycosylation (CDG) form a rapidly growing group of more than 20 inborn errors of metabolism. Most patients are identified at the pediatric age with multisystem disease. There is no systematic review on the long-term outcome and clinical presentation in adult patients. Here, we review the adult phenotype in 78 CDG patients diagnosed with 18 different forms of N-glycosylation defects. Characteristics include intellectual disability, speech disorder and abnormal gait. After puberty, symptoms might remain non-progressive and patients may lead a socially functional life. Thrombosis and progressive symptoms, such as peripheral neuropathy, scoliosis and visual demise are specifically common in PMM2-CDG. Especially in adult patients, diagnostic glycosylation screening can be mildly abnormal or near-normal, hampering diagnosis. Features of adult CDG patients significantly differ from the pediatric phenotype. Non-syndromal intellectual disability, or congenital malformations in different types of CDG and decreasing sensitivity of screening might be responsible for the CDG cases remaining undiagnosed until adulthood.
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Affiliation(s)
- David F G J Wolthuis
- Hayward Genetics Center, Tulane University Medical School, New Orleans, LA, 70112, USA
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8
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Funke S, Gardeitchik T, Kouwenberg D, Mohamed M, Wortmann SB, Korsch E, Adamowicz M, Al-Gazali L, Wevers RA, Horvath A, Lefeber DJ, Morava E. Perinatal and early infantile symptoms in congenital disorders of glycosylation. Am J Med Genet A 2013; 161A:578-84. [PMID: 23401092 DOI: 10.1002/ajmg.a.35702] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Accepted: 09/07/2012] [Indexed: 12/16/2022]
Abstract
Congenital disorders of glycosylation (CDG) are a rapidly growing family of inborn errors. Screening for CDG in suspected cases is usually performed in the first year of life by serum transferrin isoelectric focusing or mass spectrometry. Based on the transferrin analysis patients can be biochemically diagnosed with a type 1 or type 2 transferrin pattern, and labeled as CDG-I, or CDG-II. The diagnosis of CDG is frequently delayed due to the highly variable phenotype, some cases showing single organ involvement and others mimicking syndromes, like skeletal dysplasia, cutis laxa syndrome, or congenital muscle dystrophy. The aim of our study was to evaluate perinatal abnormalities and early discriminative symptoms in 58 patients consecutively diagnosed with diverse CDG-subtypes. Neonatal findings and clinical features in the first months of life were studied in 36 children with CDG-I and 22 with CDG-II. Maternal complications were found in five, small for gestational age in nine patients. Five children had abnormal neonatal screening results for hypothyroidism. Congenital microcephaly and neonatal seizures were common in CDG-II. Inverted nipples were uncommon with 5 out of 58 children. Dysmorphic features were mostly nonspecific, except for cutis laxa. Early complications included feeding problems, cardiomyopathy, thrombosis, and bleeding. Cases presenting in the neonatal period had the highest mortality rate. Survival in CDG patients is highly dependent on early intervention therapy. We recommend low threshold screening for glycosylation disorders in infants with neurologic symptoms, even in the absence of abnormal fat distribution. Growth retardation and neonatal bleeding increase suspicion for CDG.
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Affiliation(s)
- Simone Funke
- Hayward Genetics Center, Tulane University Medical Center, New Orleans, Louisiana, USA
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9
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Abstract
Congenital disorders of glycosylation comprise most of the nearly 70 genetic disorders known to be caused by impaired synthesis of glycoconjugates. The effects are expressed in most organ systems, and most involve the nervous system. Typical manifestations include structural abnormalities (eg, rapidly progressive cerebellar atrophy), myopathies (including congenital muscular dystrophies and limb-girdle dystrophies), strokes and stroke-like episodes, epileptic seizures, developmental delay, and demyelinating neuropathy. Patients can also have neurological symptoms associated with coagulopathies, immune dysfunction with or without infections, and cardiac, renal, or hepatic failure, which are common features of glycosylation disorders. The diagnosis of congenital disorder of glycosylation should be considered for any patient with multisystem disease and in those with more specific phenotypic features. Measurement of concentrations of selected glycoconjugates can be used to screen for many of these disorders, and molecular diagnosis is becoming more widely available in clinical practice. Disease-modifying treatments are available for only a few disorders, but all affected individuals benefit from early diagnosis and aggressive management.
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Affiliation(s)
- Hudson H Freeze
- Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA.
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10
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Abstract
PURPOSE OF REVIEW Congenital disorders of glycosylation (CDG) have grown enormously since the discovery of the first protein glycosylation defect in 1980, presenting with a broad clinical spectrum. Expansion in number and complexity of the CDG group has even necessitated a new nomenclature. By 2011, the CDG group includes lipid glycosylation disorders and other related processes and almost 50 distinct disorders. RECENT FINDINGS Current research has not only expanded the spectrum of CDG types, but has also given novel insight into those previously described. The discovery of genetic defects in the conserved oligomeric Golgi complex, affecting protein glycosylation and processing through the secretory pathway, raised the concept of 'secondary' glycosylation disorders. The number of lipid glycosylation disorders, linking lipid synthesis to CDG, that were previously regarded as rare, is also increasing rapidly. In other areas of research, the bridge between muscular dystrophies and metabolic disorders is being further reinforced with the discovery of additional defects in the DPM-CDG subgroup, a CDG characterized by significant muscle involvement. SUMMARY It is of great importance that clinicians stay up-to-date on the field of CDG and consider it in their differential diagnosis of unknown syndromal presentations. Nevertheless, many advances have yet to be made, including information on the natural course of CDG. The lack of treatment for nearly all CDG types is striking, and the field must continue to push for innovative therapies. Clinicians and researchers must work together to describe the natural course and, most importantly, collaborate to find new therapies.
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11
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Achouitar S, Mohamed M, Gardeitchik T, Wortmann SB, Sykut-Cegielska J, Ensenauer R, de Baulny HO, Õunap K, Martinelli D, de Vries M, McFarland R, Kouwenberg D, Theodore M, Wijburg F, Grünewald S, Jaeken J, Wevers RA, Nijtmans L, Elson J, Morava E. Nijmegen paediatric CDG rating scale: a novel tool to assess disease progression. J Inherit Metab Dis 2011; 34:923-7. [PMID: 21541726 PMCID: PMC3232068 DOI: 10.1007/s10545-011-9325-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2010] [Revised: 03/22/2011] [Accepted: 03/25/2011] [Indexed: 11/21/2022]
Abstract
Congenital disorders of glycosylation (CDG) are a group of clinically heterogeneous inborn errors of metabolism. At present, treatment is available for only one CDG, but potential treatments for the other CDG are on the horizon. It will be vitally important in clinical trials of such agents to have a clear understanding of both the natural history of CDG and the corresponding burden of disability suffered by patients. To date, no multicentre studies have attempted to document the natural history of CDG. This is in part due to the lack of a reliable assessment tool to score CDG's diverse clinical spectrum. Based on our earlier experience evaluating disease progression in disorders of oxidative phosphorylation, we developed a practical and semi-quantitative rating scale for children with CDG. The Nijmegen Paediatric CDG Rating Scale (NPCRS) has been validated in 12 children, offering a tool to objectively monitor disease progression. We undertook a successful trial of the NPCRS with a collaboration of nine experienced physicians, using video records of physical and neurological examination of patients. The use of NPCRS can facilitate both longitudinal and natural history studies that will be essential for future interventions.
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Affiliation(s)
- Samira Achouitar
- Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department of Pediatrics, Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Miski Mohamed
- Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department of Pediatrics, Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Thatjana Gardeitchik
- Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department of Pediatrics, Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Saskia B. Wortmann
- Department of Pediatrics, Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Jolanta Sykut-Cegielska
- Department of Metabolic Diseases, Endocrinology and Diabetology, The Children’s Memorial Health Institute, Warsaw, Poland
| | - Regina Ensenauer
- Dr. von Hauner Children’s Hospital, Children’s Research Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Hélène Ogier de Baulny
- Pediatric Neurology and Metabolic Disease, Robert Debré University Hospital, APHP, Paris, France
| | - Katrin Õunap
- Department of Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
| | - Diego Martinelli
- Division of Metabolism, Bambino Gesu Children’s Hospital, Rome, Italy
| | - Maaike de Vries
- Department of Pediatrics, Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Robert McFarland
- Department of Paediatric Neurology, Newcastle General Hospital, Newcastle-upon-Tyne, UK
| | - Dorus Kouwenberg
- Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department of Pediatrics, Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Miranda Theodore
- Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Frits Wijburg
- Department of Pediatrics, University Medical Center Amsterdam, Amsterdam, The Netherlands
| | | | - Jaak Jaeken
- Department of Pediatrics, University of Leuven, Leuven, Belgium
| | - Ron A. Wevers
- Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Laboratory for Genetic Metabolic and Endocrine Diseases, Nijmegen, The Netherlands
| | - Leo Nijtmans
- Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department of Pediatrics, Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Joanna Elson
- Mitochondrial Research Group, School of Neurology, Neurobiology, and Psychiatry, The University of Newcastle upon Tyne, Newcastle upon Tyne, UK
| | - Eva Morava
- Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department of Pediatrics, Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
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