1
|
Li S, Li Z, Wu Q, Luo X, Shen Y. Psychiatric assessment and therapy in an adolescent with ALG6-CDG: a six-month follow-up case report. Eur Child Adolesc Psychiatry 2024:10.1007/s00787-024-02564-x. [PMID: 39141102 DOI: 10.1007/s00787-024-02564-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/07/2024] [Indexed: 08/15/2024]
Abstract
ALG6-congenital disorder of glycosylation (ALG6-CDG) is a complex of rare inherited disorders caused by mutations in the ALG6 gene, which encodes the α-1,3-glucosyltransferase enzyme required for N-glycosylation. ALG6-CDG affects multiple systems and exhibits clinical heterogeneity. Besides developmental delays and neurological signs and symptoms, behavioral and psychological symptoms are also an important group of clinical features of ALG6-CDG. Here, we present the case of a 17-year-old Chinese girl with ALG6-CDG who first visited the psychiatric department with apathy, language reduction, and substupor symptoms. The psychiatric assessments and treatment processes performed are described and discussed in this report. During diagnostic process, we found a novel mutation, c.849delT, in ALG6 by whole-exome sequencing. The patient's symptoms improved with escitalopram and risperidone treatment. However, above a certain dosage, she was sensitive to extrapyramidal side effects. This study accumulates clinical experience for diagnosing and treating ALG6-CDG and improves our understanding of this rare genetic disorder.
Collapse
Affiliation(s)
- Sihong Li
- Department of Psychiatry, and National Clinical Research Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China
| | - Zexuan Li
- Department of Psychiatry, and National Clinical Research Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China
| | - Qiuxia Wu
- Department of Psychiatry, and National Clinical Research Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China
| | - Xuerong Luo
- Department of Psychiatry, and National Clinical Research Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China.
| | - Yidong Shen
- Department of Psychiatry, and National Clinical Research Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China.
| |
Collapse
|
2
|
Monson E, Cideciyan AV, Roman AJ, Sumaroka A, Swider M, Wu V, Viarbitskaya I, Jacobson SG, Fliesler SJ, Pittler SJ. Inherited Retinal Degeneration Caused by Dehydrodolichyl Diphosphate Synthase Mutation-Effect of an ALG6 Modifier Variant. Int J Mol Sci 2024; 25:1004. [PMID: 38256083 PMCID: PMC10816542 DOI: 10.3390/ijms25021004] [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: 12/11/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 01/24/2024] Open
Abstract
Modern advances in disease genetics have uncovered numerous modifier genes that play a role in the severity of disease expression. One such class of genetic conditions is known as inherited retinal degenerations (IRDs), a collection of retinal degenerative disorders caused by mutations in over 300 genes. A single missense mutation (K42E) in the gene encoding the enzyme dehydrodolichyl diphosphate synthase (DHDDS), which is required for protein N-glycosylation in all cells and tissues, causes DHDDS-IRD (retinitis pigmentosa type 59 (RP59; OMIM #613861)). Apart from a retinal phenotype, however, DHDDS-IRD is surprisingly non-syndromic (i.e., without any systemic manifestations). To explore disease pathology, we selected five glycosylation-related genes for analysis that are suggested to have disease modifier variants. These genes encode glycosyltransferases (ALG6, ALG8), an ER resident protein (DDOST), a high-mannose oligosaccharyl transferase (MPDU1), and a protein N-glycosylation regulatory protein (TNKS). DNA samples from 11 confirmed DHDDS (K42E)-IRD patients were sequenced at the site of each candidate genetic modifier. Quantitative measures of retinal structure and function were performed across five decades of life by evaluating foveal photoreceptor thickness, visual acuity, foveal sensitivity, macular and extramacular rod sensitivity, and kinetic visual field extent. The ALG6 variant, (F304S), was correlated with greater macular cone disease severity and less peripheral rod disease severity. Thus, modifier gene polymorphisms may account for a significant portion of phenotypic variation observed in human genetic disease. However, the consequences of the polymorphisms may be counterintuitively complex in terms of rod and cone populations affected in different regions of the retina.
Collapse
Affiliation(s)
- Elisha Monson
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - Artur V. Cideciyan
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (A.J.R.); (A.S.); (M.S.); (V.W.); (I.V.)
| | - Alejandro J. Roman
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (A.J.R.); (A.S.); (M.S.); (V.W.); (I.V.)
| | - Alexander Sumaroka
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (A.J.R.); (A.S.); (M.S.); (V.W.); (I.V.)
| | - Malgorzata Swider
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (A.J.R.); (A.S.); (M.S.); (V.W.); (I.V.)
| | - Vivian Wu
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (A.J.R.); (A.S.); (M.S.); (V.W.); (I.V.)
| | - Iryna Viarbitskaya
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (A.J.R.); (A.S.); (M.S.); (V.W.); (I.V.)
| | - Samuel G. Jacobson
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (A.J.R.); (A.S.); (M.S.); (V.W.); (I.V.)
| | - Steven J. Fliesler
- Departments of Ophthalmology and Biochemistry, and Neuroscience Graduate Program, Jacobs School of Medicine and Biomedical Sciences, State University of New York—University at Buffalo, Buffalo, NY 14203, USA;
- Research Service, VA Western NY Healthcare System, Buffalo, NY 14215, USA
| | - Steven J. Pittler
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
- Vision Science Research Center, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| |
Collapse
|
3
|
Clark DJ, Murray T, Drees M, Kulkarni N. A Case of ALG6-CDG with Explosive Onset of Intractable Epilepsy During Infancy. Child Neurol Open 2023; 10:2329048X231153781. [PMID: 36756224 PMCID: PMC9900650 DOI: 10.1177/2329048x231153781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 12/15/2022] [Accepted: 01/09/2023] [Indexed: 02/05/2023] Open
Abstract
ALG6-CDG is a rare, but second most common, type 1 congenital disorder of glycosylation (CDG) caused by a defect in the α-1-3-glucosyltransferase (ALG6) enzyme in the N-glycan assembly pathway. Many mutations have been identified and inherited in an autosomal recessive pattern. There are less than 100 ALG6-CDG cases reported, all sharing the phenotype of hypotonia and developmental delay. The majority (perhaps >70%) have seizures, but a minority have intractable epilepsy or epileptic encephalopathy. We report the clinical course, EEG findings, and neuroimaging of a child found to have compound heterozygous alleles c.257 + 5G > A and c.680G > A (p.G227E) who developed explosive onset of intractable epilepsy and epileptic encephalopathy. Initially, CDG was not suspected due to its rarity and lack of multi-organ system involvement, but rapid whole exam sequence (8-day turnaround) revealed the specific diagnosis quickly.
Collapse
Affiliation(s)
- Daniel James Clark
- Division of Neurology, Nationwide Children's
Hospital, Columbus, OH, USA,Daniel James Clark, Division of Neurology,
Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA.
| | - Thomas Murray
- Division of Neurology, Nationwide Children's
Hospital, Columbus, OH, USA
| | | | - Neil Kulkarni
- Division of Neurology, Nationwide Children's
Hospital, Columbus, OH, USA
| |
Collapse
|
4
|
Structure and mechanism of the ER-based glucosyltransferase ALG6. Nature 2020; 579:443-447. [PMID: 32103179 DOI: 10.1038/s41586-020-2044-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 01/06/2020] [Indexed: 01/03/2023]
Abstract
In eukaryotic protein N-glycosylation, a series of glycosyltransferases catalyse the biosynthesis of a dolichylpyrophosphate-linked oligosaccharide before its transfer onto acceptor proteins1. The final seven steps occur in the lumen of the endoplasmic reticulum (ER) and require dolichylphosphate-activated mannose and glucose as donor substrates2. The responsible enzymes-ALG3, ALG9, ALG12, ALG6, ALG8 and ALG10-are glycosyltransferases of the C-superfamily (GT-Cs), which are loosely defined as containing membrane-spanning helices and processing an isoprenoid-linked carbohydrate donor substrate3,4. Here we present the cryo-electron microscopy structure of yeast ALG6 at 3.0 Å resolution, which reveals a previously undescribed transmembrane protein fold. Comparison with reported GT-C structures suggests that GT-C enzymes contain a modular architecture with a conserved module and a variable module, each with distinct functional roles. We used synthetic analogues of dolichylphosphate-linked and dolichylpyrophosphate-linked sugars and enzymatic glycan extension to generate donor and acceptor substrates using purified enzymes of the ALG pathway to recapitulate the activity of ALG6 in vitro. A second cryo-electron microscopy structure of ALG6 bound to an analogue of dolichylphosphate-glucose at 3.9 Å resolution revealed the active site of the enzyme. Functional analysis of ALG6 variants identified a catalytic aspartate residue that probably acts as a general base. This residue is conserved in the GT-C superfamily. Our results define the architecture of ER-luminal GT-C enzymes and provide a structural basis for understanding their catalytic mechanisms.
Collapse
|
5
|
Mostile G, Barone R, Nicoletti A, Rizzo R, Martinelli D, Sturiale L, Fiumara A, Jankovic J, Zappia M. Hyperkinetic movement disorders in congenital disorders of glycosylation. Eur J Neurol 2019; 26:1226-1234. [PMID: 31132195 DOI: 10.1111/ene.14007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 05/14/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND PURPOSE Congenital disorders of glycosylation (CDG) represent an increasing number of rare inherited metabolic diseases associated with abnormal glycan metabolism and disease onset in infancy or early childhood. Most CDG are multisystemic diseases mainly affecting the central nervous system. The aim of the current study was to investigate hyperkinetic movement disorders in patients affected by CDG and to characterize phenomenology based on CDG subtypes. METHODS Subjects were identified from a cohort of patients with CDG who were referred to the University Hospital of Catania, Italy. Patients were evaluated by neurologists with expertise in movement disorders and videotaped using a standardized protocol. RESULTS A variety of hyperkinetic movement disorders was detected in eight unrelated CDG patients. Involuntary movements were generally observed early in childhood, maintaining a clinical stability over time. Distribution ranged from a generalized, especially in younger subjects, to a segmental/multifocal involvement. In patients with phosphomannomutase 2 CDG, the principal movement disorders included dystonia and choreo-athetosis. In patients affected by other CDG types, the movement disorders ranged from pure generalized chorea to mixed movement disorders including dystonia and complex stereotypies. CONCLUSIONS Hyperkinetic movement disorder is a key clinical feature in patients with CDG. CDG should be considered in the differential diagnosis of childhood-onset dyskinesia, especially when associated with ataxia, developmental delay, intellectual disability, autism or seizure disorder.
Collapse
Affiliation(s)
- G Mostile
- Neurology Clinic, Department 'G.F. Ingrassia', Section of Neurosciences, University of Catania, Catania, Italy
| | - R Barone
- Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy.,Regional Referral Center for Inborn Errors Metabolism, Pediatric Clinic, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy.,Institute for Polymers Composites and Biomaterials, CNR, Catania, Italy
| | - A Nicoletti
- Neurology Clinic, Department 'G.F. Ingrassia', Section of Neurosciences, University of Catania, Catania, Italy
| | - R Rizzo
- Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - D Martinelli
- Division of Metabolism, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - L Sturiale
- Institute for Polymers Composites and Biomaterials, CNR, Catania, Italy
| | - A Fiumara
- Regional Referral Center for Inborn Errors Metabolism, Pediatric Clinic, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - J Jankovic
- Parkinson's Disease Center and Movement Disorder Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - M Zappia
- Neurology Clinic, Department 'G.F. Ingrassia', Section of Neurosciences, University of Catania, Catania, Italy
| |
Collapse
|
6
|
Chang IJ, He M, Lam CT. Congenital disorders of glycosylation. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:477. [PMID: 30740408 DOI: 10.21037/atm.2018.10.45] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Congenital disorders of glycosylation are a genetically and clinically heterogeneous group of >130 diseases caused by defects in various steps along glycan modification pathways. The vast majority of these monogenic diseases are autosomal recessive and have multi-systemic manifestations, mainly growth failure, developmental delay, facial dysmorphisms, and variable coagulation and endocrine abnormalities. Carbohydrate deficient transferrin (CDT) and protein-linked glycan analysis with mass spectrometry can diagnose some subtypes of congenital disorders of glycosylation (CDG), while many currently rely on massively parallel genomic sequencing for diagnosis. Early detection is important, as a few of these disorders are treatable. Molecular and biochemical techniques continue to further our understanding of this rapidly expanding group of clinically and genetically diverse disorders.
Collapse
Affiliation(s)
- Irene J Chang
- Division of Biochemical Genetics, Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Miao He
- Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Christina T Lam
- Division of Biochemical Genetics, Department of Pediatrics, University of Washington, Seattle, Washington, USA
| |
Collapse
|
7
|
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.
Collapse
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.
| |
Collapse
|
8
|
Wong SYW, Beamer LJ, Gadomski T, Honzik T, Mohamed M, Wortmann SB, Brocke Holmefjord KS, Mork M, Bowling F, Sykut-Cegielska J, Koch D, Ackermann A, Stanley CA, Rymen D, Zeharia A, Al-Sayed M, Marquardt T, Jaeken J, Lefeber D, Conrad DF, Kozicz T, Morava E. Defining the Phenotype and Assessing Severity in Phosphoglucomutase-1 Deficiency. J Pediatr 2016; 175:130-136.e8. [PMID: 27206562 DOI: 10.1016/j.jpeds.2016.04.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 01/22/2016] [Accepted: 04/07/2016] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To define phenotypic groups and identify predictors of disease severity in patients with phosphoglucomutase-1 deficiency (PGM1-CDG). STUDY DESIGN We evaluated 27 patients with PGM1-CDG who were divided into 3 phenotypic groups, and group assignment was validated by a scoring system, the Tulane PGM1-CDG Rating Scale (TPCRS). This scale evaluates measurable clinical features of PGM1-CDG. We examined the relationship between genotype, enzyme activity, and TPCRS score by using regression analysis. Associations between the most common clinical features and disease severity were evaluated by principal component analysis. RESULTS We found a statistically significant stratification of the TPCRS scores among the phenotypic groups (P < .001). Regression analysis showed that there is no significant correlation between genotype, enzyme activity, and TPCRS score. Principal component analysis identified 5 variables that contributed to 54% variance in the cohort and are predictive of disease severity: congenital malformation, cardiac involvement, endocrine deficiency, myopathy, and growth. CONCLUSIONS We established a scoring algorithm to reliably evaluate disease severity in patients with PGM1-CDG on the basis of their clinical history and presentation. We also identified 5 clinical features that are predictors of disease severity; 2 of these features can be evaluated by physical examination, without the need for specific diagnostic testing and thus allow for rapid assessment and initiation of therapy.
Collapse
Affiliation(s)
- Sunnie Yan-Wai Wong
- Hayward Genetics Center, Tulane University School of Medicine, New Orleans, LA.
| | - Lesa J Beamer
- Biochemistry and Chemistry Departments, University of Missouri, Columbia, MO
| | - Therese Gadomski
- Hayward Genetics Center, Tulane University School of Medicine, New Orleans, LA
| | - Tomas Honzik
- Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Czech Republic
| | - Miski Mohamed
- Department of Pediatrics, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Saskia B Wortmann
- Salzburger Landeskliniken, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | | | - Marit Mork
- Department of Pediatric Habilitation, Stavanger University Hospital, Stavanger, Norway
| | - Francis Bowling
- Biochemical Diseases, Mater Children's Hospital, South Brisbane, Queensland, Australia
| | - Jolanta Sykut-Cegielska
- National Consultant in Paediatric Metabolic Medicine, Screening Department, The Institute of Mother and Child, Warsaw, Poland
| | - Dieter Koch
- Pediatric Cardiology, Bergisch Gladbacher Köln, Germany
| | - Amanda Ackermann
- Pediatric Endocrinology, The Children's Hospital of Philadelphia, Philadelphia, PA
| | - Charles A Stanley
- Pediatric Endocrinology, The Children's Hospital of Philadelphia, Philadelphia, PA
| | - Daisy Rymen
- Department of Pediatrics, Universitair Ziekenhuis Leuven, Leuven, Belgium
| | - Avraham Zeharia
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Moeen Al-Sayed
- Department of Medical Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Thomas Marquardt
- Department of Pediatrics, University of Münster, Münster, Germany
| | - Jaak Jaeken
- Centre for Metabolic Diseases, University Hospital Gasthuisberg, Herestraat, Leuven, Belgium
| | - Dirk Lefeber
- Department of Neurology, Radboudumc, Nijmegen, The Netherlands
| | - Donald F Conrad
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO
| | - Tamas Kozicz
- Hayward Genetics Center, Tulane University School of Medicine, New Orleans, LA
| | - Eva Morava
- Hayward Genetics Center, Tulane University School of Medicine, New Orleans, LA; Department of Pediatrics, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
9
|
Kane M, Davids M, Adams C, Wolfe L, Cheung H, Gropman A, Huang Y, Ng B, Freeze H, Adams D, Gahl W, Boerkoel C, Boerkoel CF. Mitotic Intragenic Recombination: A Mechanism of Survival for Several Congenital Disorders of Glycosylation. Am J Hum Genet 2016; 98:339-46. [PMID: 26805780 DOI: 10.1016/j.ajhg.2015.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 12/09/2015] [Indexed: 10/22/2022] Open
Abstract
Congenital disorders of glycosylation (CDGs) are disorders of abnormal protein glycosylation that affect multiple organ systems. Because most CDGs have been described in only a few individuals, our understanding of the associated phenotypes and the mechanisms of individual survival are limited. In the process of studying two siblings, aged 6 and 11 years, with MOGS-CDG and biallelic MOGS (mannosyl-oligosaccharide glucosidase) mutations (GenBank: NM_006302.2; c.[65C>A; 329G>A] p.[Ala22Glu; Arg110His]; c.[370C>T] p.[Gln124(∗)]), we noted that their survival was much longer than the previous report of MOGS-CDG, in a child who died at 74 days of age. Upon mutation analysis, we detected multiple MOGS genotypes including wild-type alleles in their cultured fibroblast and peripheral blood DNA. Further analysis of DNA from cultured fibroblasts of six individuals with compound heterozygous mutations of PMM2 (PMM2-CDG), MPI (MPI-CDG), ALG3 (ALG3-CDG), ALG12 (ALG12-CDG), DPAGT1 (DPAGT1-CDG), and ALG1 (ALG1-CDG) also identified multiple genotypes including wild-type alleles for each. Droplet digital PCR showed a ratio of nearly 1:1 wild-type to mutant alleles for most, but not all, mutations. This suggests that mitotic recombination contributes to the survival and the variable expressivity of individuals with compound heterozygous CDGs. This also provides an explanation for prior observations of a reduced frequency of homozygous mutations and might contribute to increased levels of residual enzyme activity in cultured fibroblasts of individuals with MPI- and PMM2-CDGs.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Cornelius F Boerkoel
- Department of Medical Genetics, University of British Columbia, Vancouver, BC V6H 3N1, Canada
| |
Collapse
|
10
|
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
|