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Moghimi P, Hashemi-Gorji F, Jamshidi S, Tehrani Fateh S, Salehpour S, Sadeghi H, Norouzi Rostami F, Mirfakhraie R, Miryounesi M, Ghasemi MR. Broadening the Phenotype and Genotype Spectrum of Glycogen Storage Disease by Unraveling Novel Variants in an Iranian Patient Cohort. Biochem Genet 2024:10.1007/s10528-024-10787-5. [PMID: 38619706 DOI: 10.1007/s10528-024-10787-5] [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: 12/02/2023] [Accepted: 03/15/2024] [Indexed: 04/16/2024]
Abstract
Glycogen storage diseases (GSDs) are a group of rare inherited metabolic disorders characterized by clinical, locus, and allele heterogeneity. This study aims to investigate the phenotype and genotype spectrum of GSDs in a cohort of 14 families from Iran using whole-exome sequencing (WES) and variant analysis. WES was performed on 14 patients clinically suspected of GSDs. Variant analysis was performed to identify genetic variants associated with GSDs. A total of 13 variants were identified, including six novel variants, and seven previously reported pathogenic variants in genes such as AGL, G6PC, GAA, PYGL, PYGM, GBE1, SLC37A4, and PHKA2. Most types of GSDs observed in the cohort were associated with hepatomegaly, which was the most common clinical presentation. This study provides valuable insights into the phenotype and genotype spectrum of GSDs in a cohort of Iranian patients. The identification of novel variants adds to the growing body of knowledge regarding the genetic landscape of GSDs and has implications for genetic counseling and future therapeutic interventions. The diverse nature of GSDs underscores the need for comprehensive genetic testing methods to improve diagnostic accuracy. Continued research in this field will enhance our understanding of GSDs, ultimately leading to improved management and outcomes for individuals affected by these rare metabolic disorders.
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Affiliation(s)
- Parinaz Moghimi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- School of Medicine, Islamic Azad University, Tehran Medical sciences, Tehran, Iran
| | - Farzad Hashemi-Gorji
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sanaz Jamshidi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Shadab Salehpour
- Department of Pediatrics, Clinical Research Development Unit, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Sadeghi
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Reza Mirfakhraie
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Miryounesi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Mohammad-Reza Ghasemi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Yu J, Ling X, Chen L, Fang Y, Lin H, Lou J, Ren Y, Chen J. Genotypic and phenotypic features of 39 Chinese patients with glycogen storage diseases type I, VI, and IX. Clin Genet 2024. [PMID: 38576397 DOI: 10.1111/cge.14530] [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: 01/10/2024] [Revised: 03/19/2024] [Accepted: 03/28/2024] [Indexed: 04/06/2024]
Abstract
Glycogen storage diseases (GSDs) are abnormally inherited glycogen metabolism mainly affecting the liver, muscles, and heart. Deficiency of proteins involved in glycogen metabolism caused by genetic mutations are responsible for different subtype of GSDs. However, there are still some challenges in diagnosing GSD. This study includes 39 suspected GSDs patients from unrelated families in China. Next-generation sequencing (NGS) was used to investigate the reason for their diseases at the genetic level. Finally, all 39 patients were diagnosed with GSDs, including 20 GSD-Ia, 4 GSD-VI, and 15 GSD IX (12 GSD-IXa patients and 3 GSD-IXb patients). Thirty-two mutations in G6PC1, PYGL, PHKA2, and PHKB genes were identified, with 14 of them being novel variants. The pathogenicity of novel variants was classified according to ACMG guildlines and predicted by in slico algorithms. Mutations p.L216L and p.R83H in G6PC1 gene may be the hot spot mutation in Chinese. Hearing impairment is a rare clinical feature of GSD Ia, which has also been observed in our cohort. The severity of GSD VI and IX was indicated by our patients. Close follow-up should be applied to GSD VI and IX patients. Our findings provided evidence for building the phenotype-genotype of GSDs and expanded the mutation spectrum of related genes.
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Affiliation(s)
- Jindan Yu
- Gastroenterology Department, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | | | - Lingli Chen
- Gastroenterology Department, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Youhong Fang
- Gastroenterology Department, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Haihua Lin
- Gastroenterology Department, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Jingan Lou
- Gastroenterology Department, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Yanqi Ren
- Grandomics Biosciences, Beijing, China
| | - Jie Chen
- Gastroenterology Department, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
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Long Q, Luo Y, Zeng M, Ye T. Type-VI glycogen storage disease with compound mutation of the PYGL gene. Asian J Surg 2024; 47:1919-1920. [PMID: 38182518 DOI: 10.1016/j.asjsur.2023.12.127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 12/25/2023] [Indexed: 01/07/2024] Open
Affiliation(s)
- Qin Long
- Department of Clinical Laboratory, Yibin Maternal and Child Health Care Hospital, Sichuan, 644000, PR China
| | - Yanan Luo
- Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, Sichuan, 646000, PR China
| | - Mei Zeng
- Department of Clinical Laboratory, Yibin Maternal and Child Health Care Hospital, Sichuan, 644000, PR China
| | - Ting Ye
- Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, Sichuan, 646000, PR China.
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Tao Z, Mao Y, Hu Y, Tang X, Wang J, Zeng N, Bao Y, Luo F, Wu C, Jiang F. Identification and immunological characterization of endoplasmic reticulum stress-related molecular subtypes in bronchopulmonary dysplasia based on machine learning. Front Physiol 2023; 13:1084650. [PMID: 36699685 PMCID: PMC9868568 DOI: 10.3389/fphys.2022.1084650] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 12/23/2022] [Indexed: 01/11/2023] Open
Abstract
Introduction: Bronchopulmonary dysplasia (BPD) is a life-threatening lung illness that affects premature infants and has a high incidence and mortality. Using interpretable machine learning, we aimed to investigate the involvement of endoplasmic reticulum (ER) stress-related genes (ERSGs) in BPD patients. Methods: We evaluated the expression profiles of endoplasmic reticulum stress-related genes and immune features in bronchopulmonary dysplasia using the GSE32472 dataset. The endoplasmic reticulum stress-related gene-based molecular clusters and associated immune cell infiltration were studied using 62 bronchopulmonary dysplasia samples. Cluster-specific differentially expressed genes (DEGs) were identified utilizing the WGCNA technique. The optimum machine model was applied after comparing its performance with that of the generalized linear model, the extreme Gradient Boosting, the support vector machine (SVM) model, and the random forest model. Validation of the prediction efficiency was done by the use of a calibration curve, nomogram, decision curve analysis, and an external data set. Results: The bronchopulmonary dysplasia samples were compared to the control samples, and the dysregulated endoplasmic reticulum stress-related genes and activated immunological responses were analyzed. In bronchopulmonary dysplasia, two distinct molecular clusters associated with endoplasmic reticulum stress were identified. The analysis of immune cell infiltration indicated a considerable difference in levels of immunity between the various clusters. As measured by residual and root mean square error, as well as the area under the curve, the support vector machine machine model showed the greatest discriminative capacity. In the end, an support vector machine model integrating five genes was developed, and its performance was shown to be excellent on an external validation dataset. The effectiveness in predicting bronchopulmonary dysplasia subtypes was further established by decision curves, calibration curves, and nomogram analyses. Conclusion: We developed a potential prediction model to assess the risk of endoplasmic reticulum stress subtypes and the clinical outcomes of bronchopulmonary dysplasia patients, and our work comprehensively revealed the complex association between endoplasmic reticulum stress and bronchopulmonary dysplasia.
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Affiliation(s)
- Ziyu Tao
- Department of Ultrasound, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China
| | - Yan Mao
- Department of Pediatrics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yifang Hu
- Department of Geriatric Endocrinology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xinfang Tang
- Department of Nephrology, The Affiliated Lianyungang Oriental Hospital of Xuzhou Medical University, The Affiliated Lianyungang Oriental Hospital of Kangda College of Nanjing Medical University, The Affiliated Lianyungang Oriental Hospital of Bengbu Medical College, Lianyungang, China
| | - Jimei Wang
- Department of Neonatology, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China
| | - Ni Zeng
- Department of Dermatology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Yunlei Bao
- Department of Neonatology, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China
| | - Fei Luo
- Department of Neonatology, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China,*Correspondence: Feng Jiang, ; Chuyan Wu, ; Fei Luo,
| | - Chuyan Wu
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China,*Correspondence: Feng Jiang, ; Chuyan Wu, ; Fei Luo,
| | - Feng Jiang
- Department of Neonatology, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China,*Correspondence: Feng Jiang, ; Chuyan Wu, ; Fei Luo,
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Kozawa S, Yokoyama H, Urayama K, Tejima K, Doi H, Takagi S, Sato TN. Latent disease similarities and therapeutic repurposing possibilities uncovered by multi-modal generative topic modeling of human diseases. BIOINFORMATICS ADVANCES 2023; 3:vbad047. [PMID: 37123453 PMCID: PMC10133403 DOI: 10.1093/bioadv/vbad047] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 03/14/2023] [Accepted: 03/31/2023] [Indexed: 05/02/2023]
Abstract
Motivation Human diseases are characterized by multiple features such as their pathophysiological, molecular and genetic changes. The rapid expansion of such multi-modal disease-omics space provides an opportunity to re-classify diverse human diseases and to uncover their latent molecular similarities, which could be exploited to repurpose a therapeutic-target for one disease to another. Results Herein, we probe this underexplored space by soft-clustering 6955 human diseases by multi-modal generative topic modeling. Focusing on chronic kidney disease and myocardial infarction, two most life-threatening diseases, unveiled are their previously underrecognized molecular similarities to neoplasia and mental/neurological-disorders, and 69 repurposable therapeutic-targets for these diseases. Using an edit-distance-based pathway-classifier, we also find molecular pathways by which these targets could elicit their clinical effects. Importantly, for the 17 targets, the evidence for their therapeutic usefulness is retrospectively found in the pre-clinical and clinical space, illustrating the effectiveness of the method, and suggesting its broader applications across diverse human diseases. Availability and implementation The code reported in this article is available at: https://github.com/skozawa170301ktx/MultiModalDiseaseModeling. Supplementary information Supplementary data are available at Bioinformatics Advances online.
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Affiliation(s)
- Satoshi Kozawa
- Karydo TherapeutiX, Inc., Kyoto 619-0288, Japan
- The Thomas N. Sato BioMEC-X Laboratories, Advanced Telecommunications Research Institute International (ATR), Kyoto 619-0288, Japan
- ERATO Sato-Live Bio-Forecasting Project, Japan Science and Technology Agency (JST), Kyoto 619-0288, Japan
| | - Hirona Yokoyama
- Karydo TherapeutiX, Inc., Kyoto 619-0288, Japan
- The Thomas N. Sato BioMEC-X Laboratories, Advanced Telecommunications Research Institute International (ATR), Kyoto 619-0288, Japan
- V-iCliniX Laboratory, Nara Medical University, Nara 634-8521, Japan
| | - Kyoji Urayama
- Karydo TherapeutiX, Inc., Kyoto 619-0288, Japan
- The Thomas N. Sato BioMEC-X Laboratories, Advanced Telecommunications Research Institute International (ATR), Kyoto 619-0288, Japan
- ERATO Sato-Live Bio-Forecasting Project, Japan Science and Technology Agency (JST), Kyoto 619-0288, Japan
| | - Kengo Tejima
- Karydo TherapeutiX, Inc., Kyoto 619-0288, Japan
- The Thomas N. Sato BioMEC-X Laboratories, Advanced Telecommunications Research Institute International (ATR), Kyoto 619-0288, Japan
- ERATO Sato-Live Bio-Forecasting Project, Japan Science and Technology Agency (JST), Kyoto 619-0288, Japan
| | - Hotaka Doi
- Karydo TherapeutiX, Inc., Kyoto 619-0288, Japan
- The Thomas N. Sato BioMEC-X Laboratories, Advanced Telecommunications Research Institute International (ATR), Kyoto 619-0288, Japan
- V-iCliniX Laboratory, Nara Medical University, Nara 634-8521, Japan
| | - Shunki Takagi
- Karydo TherapeutiX, Inc., Kyoto 619-0288, Japan
- The Thomas N. Sato BioMEC-X Laboratories, Advanced Telecommunications Research Institute International (ATR), Kyoto 619-0288, Japan
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Dong R, Wei X, Zhang K, Song F, Lv Y, Gao M, Wang D, Ma J, Gai Z, Liu Y. Genotypic and phenotypic characteristics of 12 chinese children with glycogen storage diseases. Front Genet 2022; 13:932760. [PMID: 36105079 PMCID: PMC9465291 DOI: 10.3389/fgene.2022.932760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Glycogen storage diseases (GSDs) are known as a group of disorders characterized by genetic errors leading to accumulation of glycogen in various tissues. Since different types of GSD can sometimes be clinically indistinguishable, next generation sequencing is becoming a powerful tool for clinical diagnosis. Methods: 12 patients with suspected GSDs and their parents were enrolled in this study. The clinical and laboratory data of the patients were reviewed. Causative gene variants were identified in the patients using whole exome sequencing (WES) and verified by Sanger sequencing. Results: Genetic testing and analysis showed that 7 patients were diagnosed with GSD II (Pompe disease), 2 patients with GSD III, 1 patient with GSD VI, and 2 patients with GSD IXα. A total number of 18 variants were identified in 12 patients including 11 variants in GAA gene, 3 variants in AGL gene, 2 variants in PYGL gene and 2 variants in PHKA2 gene, of which 9 variants were reported and 9 variants were novel. SIFT, Polyphen-2, Mutation Taster, and REVEL predicted the novel variants (except GAA c.1052_1075 + 47del) to be disease-causing. The 3D structures of wild/mutant type GAA protein were predicted indicating that variants p. Trp621Gly, p. Pro541Leu, p. Ser800Ile and p. Gly293Trp might affect the proteins function via destroying hydrogen bonds or conformational constraints. Neither liver size nor laboratory findings allow for a differentiation among GSD III, GSD VI and GSD IXα. Conclusion: Our study expanded the variation spectrum of genes associated with GSDs. WES, in combination with clinical, biochemical, and pathological hallmarks, could provide accurate results for diagnosing and sub-typing GSD and related diseases in clinical setting.
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Affiliation(s)
- Rui Dong
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University (Jinan Children’s Hospital), Jinan, China
- Shandong Provincial Clinical Research Center for Children’s Health and Disease, Jinan, China
| | - Xuxia Wei
- Shandong Provincial Clinical Research Center for Children’s Health and Disease, Jinan, China
- Gastroenterology, Children’s Hospital Affiliated to Shandong University (Jinan Children’s Hospital), Jinan, China
| | - Kaihui Zhang
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University (Jinan Children’s Hospital), Jinan, China
- Shandong Provincial Clinical Research Center for Children’s Health and Disease, Jinan, China
| | - Fengling Song
- Shandong Provincial Clinical Research Center for Children’s Health and Disease, Jinan, China
- Children’s Health Department, Children’s Hospital Affiliated to Shandong University (Jinan Children’s Hospital), Jinan, China
| | - Yuqiang Lv
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University (Jinan Children’s Hospital), Jinan, China
- Shandong Provincial Clinical Research Center for Children’s Health and Disease, Jinan, China
| | - Min Gao
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University (Jinan Children’s Hospital), Jinan, China
- Shandong Provincial Clinical Research Center for Children’s Health and Disease, Jinan, China
| | - Dong Wang
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University (Jinan Children’s Hospital), Jinan, China
- Shandong Provincial Clinical Research Center for Children’s Health and Disease, Jinan, China
| | - Jian Ma
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University (Jinan Children’s Hospital), Jinan, China
- Shandong Provincial Clinical Research Center for Children’s Health and Disease, Jinan, China
| | - Zhongtao Gai
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University (Jinan Children’s Hospital), Jinan, China
- Shandong Provincial Clinical Research Center for Children’s Health and Disease, Jinan, China
- *Correspondence: Zhongtao Gai, ; Yi Liu,
| | - Yi Liu
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University (Jinan Children’s Hospital), Jinan, China
- Shandong Provincial Clinical Research Center for Children’s Health and Disease, Jinan, China
- *Correspondence: Zhongtao Gai, ; Yi Liu,
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Massese M, Tagliaferri F, Dionisi-Vici C, Maiorana A. Glycogen storage diseases with liver involvement: a literature review of GSD type 0, IV, VI, IX and XI. Orphanet J Rare Dis 2022; 17:241. [PMID: 35725468 PMCID: PMC9208159 DOI: 10.1186/s13023-022-02387-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 06/06/2022] [Indexed: 12/31/2022] Open
Abstract
Background Glycogen storage diseases (GSDs) with liver involvement are classified into types 0, I, III, IV, VI, IX and XI, depending on the affected enzyme. Hypoglycemia and hepatomegaly are hallmarks of disease, but muscular and renal tubular involvement, dyslipidemia and osteopenia can develop. Considering the paucity of literature available, herein we provide a narrative review of these latter forms of GSDs. Main body Diagnosis is based on clinical manifestations and laboratory test results, but molecular analysis is often necessary to distinguish the various forms, whose presentation can be similar. Compared to GSD type I and III, which are characterized by a more severe impact on metabolic and glycemic homeostasis, GSD type 0, VI, IX and XI are usually known to be responsive to the nutritional treatment for achieving a balanced metabolic homeostasis in the pediatric age. However, some patients can exhibit a more severe phenotype and an important progression of the liver and muscular disease. The effects of dietary adjustments in GSD type IV are encouraging, but data are limited. Conclusions Early diagnosis allows a good metabolic control, with improvement of quality of life and prognosis, therefore we underline the importance of building a proper knowledge among physicians about these rare conditions. Regular monitoring is necessary to restrain disease progression and complications.
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Affiliation(s)
- Miriam Massese
- Division of Metabolism, Department of Pediatric Subspecialties, Ospedale Pediatrico Bambino Gesù, IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy.,Center for Rare Diseases and Birth Defects, Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Francesco Tagliaferri
- Division of Metabolism, Department of Pediatric Subspecialties, Ospedale Pediatrico Bambino Gesù, IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy.,SCDU of Pediatrics, Azienda Ospedaliero-Universitaria Maggiore Della Carità, University of Piemonte Orientale, Novara, Italy
| | - Carlo Dionisi-Vici
- Division of Metabolism, Department of Pediatric Subspecialties, Ospedale Pediatrico Bambino Gesù, IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy
| | - Arianna Maiorana
- Division of Metabolism, Department of Pediatric Subspecialties, Ospedale Pediatrico Bambino Gesù, IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy.
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Grünert SC, Hannibal L, Spiekerkoetter U. The Phenotypic and Genetic Spectrum of Glycogen Storage Disease Type VI. Genes (Basel) 2021; 12:genes12081205. [PMID: 34440378 PMCID: PMC8391619 DOI: 10.3390/genes12081205] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 07/27/2021] [Accepted: 08/01/2021] [Indexed: 01/24/2023] Open
Abstract
Glycogen storage disease type VI (GSD VI) is an autosomal recessive disorder of glycogen metabolism due to mutations in the glycogen phosphorylase gene (PYGL), resulting in a deficiency of hepatic glycogen phosphorylase. We performed a systematic literature review in order to collect information on the clinical phenotypes and genotypes of all published GSD VI patients and to compare the data to those for GSD IX, a biochemically and clinically very similar disorder caused by a deficiency of phosphorylase kinase. A total of 63 genetically confirmed cases of GSD VI with clinical information were identified (median age: 5.3 years). The age at presentation ranged from 5 weeks to 38 years, with a median of 1.8 years. The main presenting symptoms were hepatomegaly and poor growth, while the most common laboratory findings at initial presentation comprised elevated activity of liver transaminases, hypertriglyceridemia, fasting hypoglycemia and postprandial hyperlactatemia. Liver biopsies (n = 37) showed an increased glycogen content in 89.2%, liver fibrosis in 32.4% and early liver cirrhosis in 10.8% of cases, respectively. No patient received a liver transplant, and one successful pregnancy was reported. Our review demonstrates that GSD VI is a disorder with broad clinical heterogeneity and a small number of patients with a severe phenotype and liver cirrhosis. Neither clinical nor laboratory findings allow for a differentiation between GSD VI and GSD IX. Early biochemical markers of disease severity or clear genotype phenotype correlations are missing. Given the overall benign and unspecific phenotype and the need for enzymatic or genetic analyses for confirmation of the diagnosis, GSD VI is likely underdiagnosed. With new treatment approaches in sight, early, pre-symptomatic diagnosis, especially with respect to hepatic cirrhosis, will become even more important.
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Affiliation(s)
- Sarah Catharina Grünert
- Department of General Paediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Centre-University of Freiburg, 79106 Freiburg, Germany;
- Correspondence: ; Tel.: +49-761-270-43000; Fax: +49-761-270-45270
| | - Luciana Hannibal
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Paediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Centre-University of Freiburg, 79106 Freiburg, Germany;
| | - Ute Spiekerkoetter
- Department of General Paediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Centre-University of Freiburg, 79106 Freiburg, Germany;
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