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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 T, Fu H, Yang A, Liang Y. Clinical and Functional Characterization of Novel AGL Variants in Two Families with Glycogen Storage Disease Type III. Int J Endocrinol 2023; 2023:6679871. [PMID: 37287601 PMCID: PMC10243941 DOI: 10.1155/2023/6679871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 04/22/2023] [Accepted: 04/27/2023] [Indexed: 06/09/2023] Open
Abstract
Purpose Glycogen storage disease type III (GSDIII) is a uncommon autosomal recessive inherited metabolic disorder, which is caused by variants in the AGL gene. The purpose of this study was to elucidate the clinical and functional features of two novel variants in two families with GSDIIIa. Methods We collected the clinical and laboratory data of the two patients. Genetic testing was performed using GSDs gene panel sequencing, and the identified variants were classified according to the American College of Medical Genetics (ACMG) criteria. The pathogenicity of the novel variants was furthermore assessed through bioinformatics analysis and cellular functional validation experiments. Results The two patients were hospitalized with abnormal liver function or hepatomegaly, which was characterized by remarkably elevated liver enzyme and muscle enzyme levels, as well as hepatomegaly, and were eventually diagnosed with GSDIIIa. Genetic analysis detected two novel variants of AGL gene in the two patients: c.1484A > G (p.Y495C), c.1981G > T (p.D661Y). Bioinformatics analysis indicated that the two novel missense mutations most likely altered the protein's conformation and therefore made the enzyme it encodes less active. Based on the ACMG criteria, both variants were considered likely pathogenic, in accordance with the functional analysis results, which demonstrated that the mutated protein was still localized in the cytoplasm and that the glycogen content of cells transfected with the mutated AGL was increased compared to cells transfected with the wild-type one. Conclusion These findings indicated that the two newly identified variants in the AGL gene (c.1484A > G; c.1981G > T) were undoubtedly pathogenic mutations, inducing a slight reduction in glycogen debranching enzyme activity and a mild increase in intracellular glycogen content. Two patients who visited us with abnormal liver function, or hepatomegaly, improved dramatically after treatment with oral uncooked cornstarch, but the effects on skeletal muscle and myocardium required further observation.
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Affiliation(s)
- Tingting Yu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Hao Fu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Aoyu Yang
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Yan Liang
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
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Conte F, Sam JE, Lefeber DJ, Passier R. Metabolic Cardiomyopathies and Cardiac Defects in Inherited Disorders of Carbohydrate Metabolism: A Systematic Review. Int J Mol Sci 2023; 24:ijms24108632. [PMID: 37239976 DOI: 10.3390/ijms24108632] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/25/2023] [Accepted: 05/02/2023] [Indexed: 05/28/2023] Open
Abstract
Heart failure (HF) is a progressive chronic disease that remains a primary cause of death worldwide, affecting over 64 million patients. HF can be caused by cardiomyopathies and congenital cardiac defects with monogenic etiology. The number of genes and monogenic disorders linked to development of cardiac defects is constantly growing and includes inherited metabolic disorders (IMDs). Several IMDs affecting various metabolic pathways have been reported presenting cardiomyopathies and cardiac defects. Considering the pivotal role of sugar metabolism in cardiac tissue, including energy production, nucleic acid synthesis and glycosylation, it is not surprising that an increasing number of IMDs linked to carbohydrate metabolism are described with cardiac manifestations. In this systematic review, we offer a comprehensive overview of IMDs linked to carbohydrate metabolism presenting that present with cardiomyopathies, arrhythmogenic disorders and/or structural cardiac defects. We identified 58 IMDs presenting with cardiac complications: 3 defects of sugar/sugar-linked transporters (GLUT3, GLUT10, THTR1); 2 disorders of the pentose phosphate pathway (G6PDH, TALDO); 9 diseases of glycogen metabolism (GAA, GBE1, GDE, GYG1, GYS1, LAMP2, RBCK1, PRKAG2, G6PT1); 29 congenital disorders of glycosylation (ALG3, ALG6, ALG9, ALG12, ATP6V1A, ATP6V1E1, B3GALTL, B3GAT3, COG1, COG7, DOLK, DPM3, FKRP, FKTN, GMPPB, MPDU1, NPL, PGM1, PIGA, PIGL, PIGN, PIGO, PIGT, PIGV, PMM2, POMT1, POMT2, SRD5A3, XYLT2); 15 carbohydrate-linked lysosomal storage diseases (CTSA, GBA1, GLA, GLB1, HEXB, IDUA, IDS, SGSH, NAGLU, HGSNAT, GNS, GALNS, ARSB, GUSB, ARSK). With this systematic review we aim to raise awareness about the cardiac presentations in carbohydrate-linked IMDs and draw attention to carbohydrate-linked pathogenic mechanisms that may underlie cardiac complications.
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Affiliation(s)
- Federica Conte
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Department of Applied Stem Cell Technologies, TechMed Centre, University of Twente, 7522 NH Enschede, The Netherlands
| | - Juda-El Sam
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Dirk J Lefeber
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Robert Passier
- Department of Applied Stem Cell Technologies, TechMed Centre, University of Twente, 7522 NH Enschede, The Netherlands
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
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Wang J, Yu Y, Cai C, Zhi X, Zhang Y, Zhao Y, Shu J. The biallelic novel pathogenic variants in AGL gene in a chinese patient with glycogen storage disease type III. BMC Pediatr 2022; 22:284. [PMID: 35578201 PMCID: PMC9109368 DOI: 10.1186/s12887-022-03252-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 03/27/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Glycogen storage disease type III (GSD III) is a rare autosomal recessive glycogenolysis disorder due to AGL gene variants, characterized by hepatomegaly, fasting hypoglycemia, hyperlipidemia, elevated hepatic transaminases, growth retardation, progressive myopathy, and cardiomyopathy. However, it is not easy to make a definite diagnosis in early stage of disease only based on the clinical phenotype and imageology due to its clinical heterogeneity. CASE PRESENTATION We report a two-year-old girl with GSD III from a nonconsanguineous Chinese family, who presented with hepatomegaly, fasting hypoglycemia, hyperlipidemia, elevated levels of transaminases. Accordingly, Sanger sequencing, whole‑exome sequencing of family trios, and qRT-PCR was performed, which revealed that the patient carried the compound heterogeneous variants, a novel frameshift mutation c.597delG (p. Q199Hfs*2) and a novel large gene fragment deletion of the entire exon 13 in AGL gene. The deletion of AGL was inherited from the proband's father and the c.597delG variant was from the mother. CONCLUSIONS In this study, we identified two novel variants c.597delG (p. Q199Hfs*2) and deletion of the entire exon 13 in AGL in a Chinese GSD III patient. We extend the mutation spectrum of AGL. We suggest that high-throughput sequencing technology can detect and screen pathogenic variant, which is a scientific basis about genetic counseling and clinical diagnosis.
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Affiliation(s)
- Jing Wang
- Department of Gastroenterology, Tianjin Children's Hospital, 300134, Tianjin, China.,Tianjin Children's Hospital (Children's Hospital of Tianjin University), 300134, Tianjin, China
| | - Yuping Yu
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), 300134, Tianjin, China.,Graduate College of Tianjin Medical University, 300070, Tianjin, China
| | - Chunquan Cai
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), 300134, Tianjin, China.,Tianjin Pediatric Research Institute, 300134, Tianjin, China.,Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, 300134, Tianjin, China
| | - Xiufang Zhi
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), 300134, Tianjin, China.,Graduate College of Tianjin Medical University, 300070, Tianjin, China
| | - Ying Zhang
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), 300134, Tianjin, China.,Graduate College of Tianjin Medical University, 300070, Tianjin, China
| | - Yu Zhao
- Department of Gastroenterology, Tianjin Children's Hospital, 300134, Tianjin, China.,Tianjin Children's Hospital (Children's Hospital of Tianjin University), 300134, Tianjin, China
| | - Jianbo Shu
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), 300134, Tianjin, China. .,Tianjin Pediatric Research Institute, 300134, Tianjin, China. .,Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, 300134, Tianjin, China. .,Tianjin Pediatric Research Institute, Tianjin Children's Hospital, No. 238 Longyan Road, Beichen District, 300134, Tianjin, China.
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Ikeda A, Makino Y, Matsubara H. Glycogen debranching pathway deduced from substrate specificity of glycogen debranching enzyme. Glycoconj J 2022; 39:345-355. [PMID: 35192094 DOI: 10.1007/s10719-022-10046-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/27/2022] [Accepted: 02/04/2022] [Indexed: 11/04/2022]
Abstract
Glycogen debranching enzyme (GDE) is bifunctional in that it exhibits both 4-α-glucanotransferase and amylo-α-1,6-glucosidase activity at two distinct catalytic sites. GDE converts the phosphorylase-limit biantennary branch [G-G-G-G-(G-G-G-G↔)G-G- residue, where G = D-glucose, hyphens represent α-1,4-glycosidic bonds, and the double-headed arrow represents an α-1,6-glycosidic bond] into a linear maltooligosyl residue, which is then subjected to phosphorylase, and glycogen degradation continues. The prevailing hypothesis regarding the glycogen debranching pathway was that 4-α-glucanotransferase converts the phosphorylase-limit biantennary branch into the G-G-G-G-G-G-G-(G↔)G-G- residue and amylo-α-1,6-glucosidase cleaves the remaining α-1,6-linked G residue. In the present study, we analyzed the substrate specificities of 4-α-glucanotransferase and amylo-α-1,6-glucosidase using fluorogenic biantennary dextrins such as G-G-G-G-(G-G-G-G↔)G-G-GPA (F4/4/2; where GPA = 1-deoxy-1-[(2-pyridyl)amino]-D-glucitol), G-(G-G-G-G↔)G-G-GPA (F1/4/2), and G-G-G-G-G-G-G-(G↔)G-G-GPA (F7/1/2). Contrary to the prevailing hypothesis, the main branch of F4/4/2 was an important donor substrate component of 4-α-glucanotransferase and did not serve as an acceptor substrate. However, when G-G-G-G-G-GPA was added to the mixture, it successfully accepted a maltotriosyl (G3-) residue from F4/4/2. In addition, amylo-α-1,6-glucosidase exhibited strong activity towards G-G-G-G-(G↔)G-G-GPA but weak activity towards F7/1/2. Furthermore, the debranching activity of GDE towards phosphorylase-limit glycogen substantially increased when methyl α-maltooligosides with lengths equal to or greater than that of methyl α-maltopentaoside (G5-OCH3) were added to the enzyme reaction mixture. Based on these results, we propose the following macroscopic debranching pathway: Via 4-α-glucanotransferase, the G3- residue of the donor branch is transferred to a long (n ≥ 5) linear Gn- residue linked to a different branching G residue.
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Affiliation(s)
- Ayato Ikeda
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Naka-ku, Sakai, Osaka, 599-8531, Japan
| | - Yasushi Makino
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Naka-ku, Sakai, Osaka, 599-8531, Japan.
| | - Hiroshi Matsubara
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Naka-ku, Sakai, Osaka, 599-8531, Japan
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Ben Chehida A, Ben Messaoud S, Ben Abdelaziz R, Mansouri H, Boudabous H, Hakim K, Ben Ali N, Ben Ameur Z, Sassi Y, Kaabachi N, Abdelhak S, Abdelmoula MS, Azzouz H, Tebib N. A lower energetic, protein and uncooked cornstarch intake is associated with a more severe outcome in glycogen storage disease type III: an observational study of 50 patients. J Pediatr Endocrinol Metab 2018; 31:979-986. [PMID: 30110253 DOI: 10.1515/jpem-2018-0151] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 05/28/2018] [Indexed: 11/15/2022]
Abstract
Background Glycogen storage disease type III (GSDIII), due to a deficiency of glycogen debrancher enzyme (GDE), is particularly frequent in Tunisia. Phenotypic particularities of Tunisian patients remain unknown. Our aim was to study complications of GSDIII in a Tunisian population and to explore factors interfering with its course. Methods A retrospective longitudinal study was conducted over 30 years (1986-2016) in the referral metabolic center in Tunisia. Results Fifty GSDIII patients (26 boys), followed for an average 6.75 years, were enrolled. At the last evaluation, the median age was 9.87 years and 24% of patients reached adulthood. Short stature persisted in eight patients and obesity in 19 patients. Lower frequency of hypertriglyceridemia (HTG) was associated with older patients (p<0.0001), higher protein diet (p=0.068) and lower caloric intake (p=0.025). Hepatic complications were rare. Cardiac involvement (CI) was frequent (91%) and occurred early at a median age of 2.6 years. Severe cardiomyopathy (50%) was related to lower doses of uncooked cornstarch (p=0.02). Neuromuscular involvement (NMI) was constant, leading to a functional discomfort in 64% of cases and was disabling in 34% of cases. Severe forms were related to lower caloric (p=0.005) and protein intake (p<0.015). Conclusions A low caloric, protein and uncooked cornstarch intake is associated with a more severe outcome in GSDIII Tunisian patients. Neuromuscular and CIs were particularly precocious and severe, even in childhood. Genetic and epigenetic factors deserve to be explored.
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Affiliation(s)
- Amel Ben Chehida
- Research Laboratory LR12SP02, Pediatric and Metabolic Department, La Rabta Hospital, Faculty of Medecine of Tunis, University of Tunis El Manar, Tunis, Tunisia
- Tunisian Association for Studying Inherited Metabolic Diseases (General Secretary), La Rabta Hospital, 1007, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
| | - Sana Ben Messaoud
- Research Laboratory LR12SP02, Pediatric and Metabolic Department, La Rabta Hospital, Faculty of Medecine of Tunis, University of Tunis El Manar, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
| | - Rim Ben Abdelaziz
- Research Laboratory LR12SP02, Pediatric and Metabolic Department, La Rabta Hospital, Faculty of Medecine of Tunis, University of Tunis El Manar, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
| | - Hajer Mansouri
- Research Laboratory LR12SP02, Pediatric and Metabolic Department, La Rabta Hospital, Faculty of Medecine of Tunis, University of Tunis El Manar, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
| | - Hela Boudabous
- Research Laboratory LR12SP02, Pediatric and Metabolic Department, La Rabta Hospital, Faculty of Medecine of Tunis, University of Tunis El Manar, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
| | - Kaouthar Hakim
- Department of Pediatric Cardiology, La Rabta Hospital, Faculty of Medecine of Tunis, University of Tunis El Manar, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
| | - Nadia Ben Ali
- Department of Neurology, Charles Nicoles Hospital, University of Tunis El Manar, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
| | - Zeineb Ben Ameur
- Research Laboratory LR12SP02, Pediatric and Metabolic Department, La Rabta Hospital, Faculty of Medecine of Tunis, University of Tunis El Manar, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
| | - Yosra Sassi
- Research Laboratory LR12SP02, Pediatric and Metabolic Department, La Rabta Hospital, Faculty of Medecine of Tunis, University of Tunis El Manar, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
| | - Neziha Kaabachi
- Department of biochemistry, La Rabta Hospital, Faculty of Medecine of Tunis, University of Tunis El Manar, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
| | - Sonia Abdelhak
- Laboratory of Biomedical Genomics and Oncogenetics (LR11IPT05), Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Mohamed Slim Abdelmoula
- Research Laboratory LR12SP02, Pediatric and Metabolic Department, La Rabta Hospital, Faculty of Medecine of Tunis, University of Tunis El Manar, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
| | - Hatem Azzouz
- Research Laboratory LR12SP02, Pediatric and Metabolic Department, La Rabta Hospital, Faculty of Medecine of Tunis, University of Tunis El Manar, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
| | - Neji Tebib
- Research Laboratory LR12SP02, Pediatric and Metabolic Department, La Rabta Hospital, Faculty of Medecine of Tunis, University of Tunis El Manar, Jabberi, Jebal Lakhdhar, Tunis, Tunisia
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[Molecular and clinical characterization of Colombian patients suffering from type III glycogen storage disease]. BIOMEDICA 2018; 38:30-42. [PMID: 29809327 DOI: 10.7705/biomedica.v38i0.3454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 04/10/2017] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Type III glycogen storage disease (GSD III) is an autosomal recessive disorder in which a mutation in the AGL gene causes deficiency of the glycogen debranching enzyme. The disease is characterized by fasting hypoglycemia, hepatomegaly and progressive myopathy. Molecular analyses of AGL have indicated heterogeneity depending on ethnic groups. The full spectrum of AGL mutations in Colombia remains unclear. OBJECTIVE To describe the clinical and molecular characteristics of ten Colombian patients diagnosed with GSD III. MATERIALS AND METHODS We recruited ten Colombian children with a clinical and biochemical diagnosis of GSD III to undergo genetic testing. The full coding exons and the relevant exon-intron boundaries of the AGL underwent Sanger sequencing to identify mutation. RESULTS All patients had the classic phenotype of the GSD III. Genetic analysis revealed a mutation p.Arg910X in two patients. One patient had the mutation p.Glu1072AspfsX36, and one case showed a compound heterozygosity with p.Arg910X and p.Glu1072AspfsX36 mutations. We also detected the deletion of AGL gene 3, 4, 5, and 6 exons in three patients. The in silico studies predicted that these defects are pathogenic. No mutations were detected in the amplified regions in three patients. CONCLUSION We found mutations and deletions that explain the clinical phenotype of GSD III patients. This is the first report with a description of the clinical phenotype and the spectrum of AGL mutations in Colombian patients. This is important to provide appropriate prognosis and genetic counseling to the patient and their relatives.
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Rhouma FB, Messai H, Hsouna S, Halim NB, Cherif W, Fadhel SB, Tiar A, Nagara M, Azzouz H, Sfar MT, Dridi MFB, Tebib N, Ayadi A, Abdelhak S, Kefi R. History of settlement of villages from Central Tunisia by studying families sharing a common founder Glycogenosis type III mutation. Mitochondrial DNA A DNA Mapp Seq Anal 2015; 27:3194-8. [PMID: 26704523 DOI: 10.3109/19401736.2015.1007331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Glycogen storage disease type III (GSD III; Cori disease; Forbes disease) is an autosomal recessive inherited metabolic disorder resulting from deficient glycogen debrancher enzyme activity in liver and muscle. In this study, we focused on a single AGL gene mutation p.W1327X in 16 Tunisian patients from rural area surrounding the region of Mahdia in Central Tunisia. This constitutes the largest pool of patients with this mutation ever described. This study was performed to trace the history of the patients' ancestries in a single region. After extraction of genomic DNA, exon 31 of AGL gene was sequenced. The patients were investigated for the hypervariable segment 1 of mitochondrial DNA and 17 Y-STR markers. We found that the p.W1327X mutation was a founder mutation in Tunisia Analysis of maternal lineages shows an admixture of autochthonous North African, sub-Saharan and a predominance of Eurasian haplogroups. Heterogeneity of maternal haplogroups indicates an ancient settlement. However, paternal gene flow was highly homogeneous and originates from the Near East. We hypothesize that the p.W1327X mutation was introduced into the Tunisian population probably by a recent migration event; then the mutation was fixed in a small region due to the high rate of consanguineous marriages and genetic drift. The screening for this mutation should be performed in priority for GSD III molecular diagnosis, for patients from the region of Mahdia and those from regions sharing the same settlement history.
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Affiliation(s)
- Faten Ben Rhouma
- a Institut Pasteur de Tunis, Laboratoire de Genomique Biomedicale et Oncogenetique LR11IPT05 , Tunis , Tunisia .,b Université Tunis El Manar , Tunis , Tunisia
| | - Habib Messai
- a Institut Pasteur de Tunis, Laboratoire de Genomique Biomedicale et Oncogenetique LR11IPT05 , Tunis , Tunisia .,b Université Tunis El Manar , Tunis , Tunisia
| | - Sana Hsouna
- a Institut Pasteur de Tunis, Laboratoire de Genomique Biomedicale et Oncogenetique LR11IPT05 , Tunis , Tunisia .,b Université Tunis El Manar , Tunis , Tunisia
| | - Nizar Ben Halim
- a Institut Pasteur de Tunis, Laboratoire de Genomique Biomedicale et Oncogenetique LR11IPT05 , Tunis , Tunisia .,b Université Tunis El Manar , Tunis , Tunisia
| | - Wafa Cherif
- a Institut Pasteur de Tunis, Laboratoire de Genomique Biomedicale et Oncogenetique LR11IPT05 , Tunis , Tunisia .,b Université Tunis El Manar , Tunis , Tunisia
| | - Sihem Ben Fadhel
- a Institut Pasteur de Tunis, Laboratoire de Genomique Biomedicale et Oncogenetique LR11IPT05 , Tunis , Tunisia .,b Université Tunis El Manar , Tunis , Tunisia
| | - Afaf Tiar
- a Institut Pasteur de Tunis, Laboratoire de Genomique Biomedicale et Oncogenetique LR11IPT05 , Tunis , Tunisia .,b Université Tunis El Manar , Tunis , Tunisia
| | - Majdi Nagara
- a Institut Pasteur de Tunis, Laboratoire de Genomique Biomedicale et Oncogenetique LR11IPT05 , Tunis , Tunisia .,b Université Tunis El Manar , Tunis , Tunisia
| | - Hatem Azzouz
- c Département de Pédiatrie , Hôpital La Rabta de Tunis, Unité des maladies métaboliques héréditaires , Tunis , Tunisia .,d Faculté de Médecine de Tunis , Tunis , Tunisia , and
| | | | - Marie-Françoise Ben Dridi
- c Département de Pédiatrie , Hôpital La Rabta de Tunis, Unité des maladies métaboliques héréditaires , Tunis , Tunisia .,d Faculté de Médecine de Tunis , Tunis , Tunisia , and
| | - Neji Tebib
- c Département de Pédiatrie , Hôpital La Rabta de Tunis, Unité des maladies métaboliques héréditaires , Tunis , Tunisia .,d Faculté de Médecine de Tunis , Tunis , Tunisia , and
| | - Abdelkarim Ayadi
- e Département de Pédiatrie , Hôpital Tahar Sfar , Mahdia , Tunisia
| | - Sonia Abdelhak
- a Institut Pasteur de Tunis, Laboratoire de Genomique Biomedicale et Oncogenetique LR11IPT05 , Tunis , Tunisia .,b Université Tunis El Manar , Tunis , Tunisia
| | - Rym Kefi
- a Institut Pasteur de Tunis, Laboratoire de Genomique Biomedicale et Oncogenetique LR11IPT05 , Tunis , Tunisia .,b Université Tunis El Manar , Tunis , Tunisia
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Rousseau-Nepton I, Okubo M, Grabs R, Mitchell J, Polychronakos C, Rodd C. A founder AGL mutation causing glycogen storage disease type IIIa in Inuit identified through whole-exome sequencing: a case series. CMAJ 2015; 187:E68-E73. [PMID: 25602008 DOI: 10.1503/cmaj.140840] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Glycogen storage disease type III is caused by mutations in both alleles of the AGL gene, which leads to reduced activity of glycogen-debranching enzyme. The clinical picture encompasses hypoglycemia, with glycogen accumulation leading to hepatomegaly and muscle involvement (skeletal and cardiac). We sought to identify the genetic cause of this disease within the Inuit community of Nunavik, in whom previous DNA sequencing had not identified such mutations. METHODS Five Inuit children with a clinical and biochemical diagnosis of glycogen storage disease type IIIa were recruited to undergo genetic testing: 2 underwent whole-exome sequencing and all 5 underwent Sanger sequencing to confirm the identified mutation. Selected DNA regions near the AGL gene were also sequenced to identify a potential founder effect in the community. In addition, control samples from 4 adults of European descent and 7 family members of the affected children were analyzed for the specific mutation by Sanger sequencing. RESULTS We identified a homozygous frame-shift deletion, c.4456delT, in exon 33 of the AGL gene in 2 children by whole-exome sequencing. Confirmation by Sanger sequencing showed the same mutation in all 5 patients, and 5 family members were found to be carriers. With the identification of this mutation in 5 probands, the estimated prevalence of genetically confirmed glycogen storage disease type IIIa in this region is among the highest worldwide (1:2500). Despite identical mutations, we saw variations in clinical features of the disease. INTERPRETATION Our detection of a homozygous frameshift mutation in 5 Inuit children determines the cause of glycogen storage disease type IIIa and confirms a founder effect.
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Affiliation(s)
- Isabelle Rousseau-Nepton
- Department of Pediatrics (Rousseau-Nepton, Mitchell, Polychronakos), Montreal Children's Hospital, Montréal, Que.; Okinaka Memorial Institute for Medical Research (Okubo), Tokyo, Japan; Endocrine Genetics Laboratory (Grabs), Montreal Children's Hospital, McGill University Health Centre, Montréal, Que.; Department of Pediatrics and Child Health (Rodd), Winnipeg, Man
| | - Minoru Okubo
- Department of Pediatrics (Rousseau-Nepton, Mitchell, Polychronakos), Montreal Children's Hospital, Montréal, Que.; Okinaka Memorial Institute for Medical Research (Okubo), Tokyo, Japan; Endocrine Genetics Laboratory (Grabs), Montreal Children's Hospital, McGill University Health Centre, Montréal, Que.; Department of Pediatrics and Child Health (Rodd), Winnipeg, Man
| | - Rosemarie Grabs
- Department of Pediatrics (Rousseau-Nepton, Mitchell, Polychronakos), Montreal Children's Hospital, Montréal, Que.; Okinaka Memorial Institute for Medical Research (Okubo), Tokyo, Japan; Endocrine Genetics Laboratory (Grabs), Montreal Children's Hospital, McGill University Health Centre, Montréal, Que.; Department of Pediatrics and Child Health (Rodd), Winnipeg, Man
| | | | - John Mitchell
- Department of Pediatrics (Rousseau-Nepton, Mitchell, Polychronakos), Montreal Children's Hospital, Montréal, Que.; Okinaka Memorial Institute for Medical Research (Okubo), Tokyo, Japan; Endocrine Genetics Laboratory (Grabs), Montreal Children's Hospital, McGill University Health Centre, Montréal, Que.; Department of Pediatrics and Child Health (Rodd), Winnipeg, Man
| | - Constantin Polychronakos
- Department of Pediatrics (Rousseau-Nepton, Mitchell, Polychronakos), Montreal Children's Hospital, Montréal, Que.; Okinaka Memorial Institute for Medical Research (Okubo), Tokyo, Japan; Endocrine Genetics Laboratory (Grabs), Montreal Children's Hospital, McGill University Health Centre, Montréal, Que.; Department of Pediatrics and Child Health (Rodd), Winnipeg, Man
| | - Celia Rodd
- Department of Pediatrics (Rousseau-Nepton, Mitchell, Polychronakos), Montreal Children's Hospital, Montréal, Que.; Okinaka Memorial Institute for Medical Research (Okubo), Tokyo, Japan; Endocrine Genetics Laboratory (Grabs), Montreal Children's Hospital, McGill University Health Centre, Montréal, Que.; Department of Pediatrics and Child Health (Rodd), Winnipeg, Man.
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Okubo M, Ucar SK, Podskarbi T, Murase T, Shin YS, Coker M. Molecular and clinical delineation of 12 patients with glycogen storage disease type III in Western Turkey. Clin Chim Acta 2015; 439:162-7. [PMID: 25451950 DOI: 10.1016/j.cca.2014.10.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Revised: 10/11/2014] [Accepted: 10/12/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Glycogen storage disease type III (GSD III; MIM #232400) is an autosomal recessive inherited disorder characterized by fasting hypoglycemia, growth retardation, hepatomegaly, progressive myopathy, and cardiomyopathy. GSD III is caused by deficiency in the glycogen debranching enzyme (gene symbol: AGL). Molecular analyses of AGL have indicated heterogeneity depending on ethnic groups. In Turkey we reported 13 different AGL mutations from GSD III patients in the Eastern region; however, the full spectrum of AGL mutations in Turkish population remains unclear. Here we investigated 12 GSD III patients mostly from Western Turkey. METHODS The full coding exons, their relevant exon-intron boundaries, and the 5'- and 3'-flanking regions of the patients' AGL were sequenced. AGL haplotypes were determined. Splicing mutations were characterized by RNA transcript analysis. RESULTS Twelve different mutations were identified: 7 novel AGL mutations [69-base pair deletion (c.1056_1082+42del69), 21-base par deletion (c.3940_3949+11del21), two small duplications (c.364_365dupCT and c.1497_1500dupAGAG), and 3 splicing mutations (c.1736-11A>G, c.3259+1G>A and c.3588+2T>G)], along with 5 known mutations (c.1019delA, c.958+1G>A, c.4161+5G>A, p.R864X and p.R1218X). Transcripts of splicing mutations (c.1736-11A>G, c.3588+2T>G and c.4161+5G>A) were shown to cause aberrant splicing. AGL haplotype analyses suggested that c.1019delA and c.958+1G>A are founder mutations in Turkish patients, while p.R864X is a recurrent mutation. CONCLUSIONS Our study broadens the spectrum of AGL mutations and demonstrates that mutations in Western Turkey are different from those in the Eastern region.
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Affiliation(s)
- Minoru Okubo
- Okinaka Memorial Institute for Medical Research, Tokyo, Japan; Department of Endocrinology and Metabolism, Toranomon Hospital, Tokyo, Japan.
| | - Sema Kalkan Ucar
- Department of Pediatric Metabolism and Nutrition, Ege University Medical Faculty, Izmir, Turkey
| | | | - Toshio Murase
- Okinaka Memorial Institute for Medical Research, Tokyo, Japan
| | - Yoon S Shin
- Molecular Genetics and Metabolism Laboratory, Munich, Germany
| | - Mahmut Coker
- Department of Pediatric Metabolism and Nutrition, Ege University Medical Faculty, Izmir, Turkey
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Basit S, Malibari O, Al Balwi AM, Abdusamad F, Abu Ismail F. A founder splice site mutation underlies glycogen storage disease type 3 in consanguineous Saudi families. Ann Saudi Med 2014; 34:390-5. [PMID: 25827695 PMCID: PMC6074555 DOI: 10.5144/0256-4947.2014.390] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Glycogen storage disease type 3 (GSD III) is an autosomal recessive disorder caused by genetic mutations in the gene AGL. AGL encodes amylo-a-1, 6-glucosidase, 4-a-glucanotransferase, a glycogen debranching enzyme. GSD III is characterized by fasting hypoglycemia, hepatomegaly, growth retardation, progressive myopathy, and cardiomyopathy due to storage of abnormally structured glycogen in both skeletal and cardiac muscles and/or liver. The aim of this study is to detect mutations underlying GSD III in Saudi patients. DESIGN AND SETTINGS A cross-sectional clinical genetic study of 5 Saudi consanguineous families examined at the metabolic clinic of the Madinah Maternity and Children Hospital. PATIENTS AND METHODS We present a biochemical and molecular analysis of 5 consanguineous Saudi families with GSD III. DNA was isolated from the peripheral blood of 31 individuals, including 12 patients, and the AGL gene was sequenced bidirectionally. DNA sequences were compared with the AGL reference sequence from the ensemble genome browser. RESULTS Genotyping and sequence analysis identified a homozygous intronic splice acceptor site mutation (IVS32-12A > G) in 4 families perfectly segregating with the phenotype. Complementary (c)DNA sequence analysis of the AGL gene revealed an 11-bp sequence insertion between exon 32 and exon 33 due to the creation of a new 3' splice site. The predicted mutant enzyme was truncated by 112 carboxyl-terminal amino acids as a result of premature termination. CONCLUSION Haplotype analysis revealed that the mutation arises as a result of founder effect, not an independent event. This is the first report of a genetic mutation in the AGL gene from Saudi Arabia. Screening for this mutation can improve genetic counseling and prenatal diagnosis of GSD III in Saudi Arabia.
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Affiliation(s)
- Sulman Basit
- Sulman Basit PhD, Center for Genetics and Inherited Diseases, Taibah University Al Madinah Al Munawarah, Saudi Arabia, T: +966-535370209,
| | | | - Alia Mahmood Al Balwi
- Sulman Basit PhD, Center for Genetics and Inherited Diseases, Taibah University Al Madinah Al Munawarah, Saudi Arabia, T: +966-535370209,
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12
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El-Karaksy H, Anwar G, El-Raziky M, Mogahed E, Fateen E, Gouda A, El-Mougy F, El-Hennawy A. Glycogen storage disease type III in Egyptian children: a single centre clinico-laboratory study. Arab J Gastroenterol 2014; 15:63-7. [PMID: 25097048 DOI: 10.1016/j.ajg.2014.01.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 01/09/2014] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND AND STUDY AIMS Glycogen storage disease type III (GSD III) is an autosomal recessive disorder caused by deficiency of glycogen debrancher enzyme and is characterised by clinical variability. PATIENTS AND METHODS We herein describe the clinical and laboratory findings in 31 Egyptian patients with GSD III presenting to the Paediatric Hepatology Unit, Cairo University, Egypt. RESULTS Eighteen patients (58%) were males. Their ages ranged between 6 months to 12 years. The main presenting complaint was progressive abdominal distention in 55%. Twelve patients (38.7%) had a history of recurrent attacks of convulsions; four had an erroneous diagnosis of hypocalcaemia and epilepsy. Doll-like facies was noted in 90%. Abdominal examination of all cases revealed abdominal distention and soft hepatomegaly which had bright echogenicity by ultrasound. Hypertriglyceridaemia was present in 93.6%, hyperlactacidaemia in 51.6% and hyperuricaemia in 19.4%. Liver biopsy showed markedly distended hepatocytes with well distinct cytoplasmic boundaries and 32% had macrovesicular fatty changes. Serum creatine kinase was elevated in 64.6% of patients and correlated positively and significantly with age (r=0.7 and P=<0.001), while serum triglycerides correlated negatively with age (r=-0.4 and P=0.05). CONCLUSION Blood glucose assessment and search for hepatomegaly in an infant with recurrent seizures may prevent delay in the diagnosis. A huge soft liver reaching the left midclavicular line that appears echogenic on ultrasonography is characteristic of GSD III. A distended hepatocyte with rarified cytoplasm is pathognomonic but not diagnostic. Hypertriglyceridaemia correlates negatively with age, in contrary to CK level.
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Affiliation(s)
- Hanaa El-Karaksy
- Department of Pediatrics, Faculty of Medicine, Cairo University, Cairo, Egypt.
| | - Ghada Anwar
- Department of Pediatrics, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Mona El-Raziky
- Department of Pediatrics, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Engy Mogahed
- Department of Pediatrics, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Ekram Fateen
- Biochemical Genetic Department, National Research Center, Cairo, Egypt
| | - Amr Gouda
- Biochemical Genetic Department, National Research Center, Cairo, Egypt
| | - Fatma El-Mougy
- Department of Chemical Pathlogy, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Ahmed El-Hennawy
- Department of Pathology, Faculty of Medicine, Cairo University, Cairo, Egypt
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Arya VB, Senniappan S, Guemes M, Hussain K. Neonatal hypoglycemia. Indian J Pediatr 2014; 81:58-65. [PMID: 23904063 DOI: 10.1007/s12098-013-1135-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 06/10/2013] [Indexed: 11/30/2022]
Abstract
Glucose is essential for cerebral metabolism. Unsurprisingly therefore, hypoglycemia may result in encephalopathy. Knowledge of the homeostatic mechanisms that maintain blood glucose concentrations within a tight range is the key for diagnosis and appropriate management of hypoglycemia. Neonatal hypoglycemia can be transient and is commonly observed in at-risk infants. A wide range of rare endocrine and metabolic disorders can present with neonatal hypoglycemia, of which congenital hyperinsulinism is responsible for the most severe form of hypoglycemia. Collection of appropriate blood samples for hormones and intermediary metabolites during an episode of hypoglycemia is critical for diagnosis and appropriate management. Prompt diagnosis with aggressive early intervention remains the mainstay of treatment to avert irreversible brain damage.
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Affiliation(s)
- Ved Bhushan Arya
- Clinical and Molecular Genetics Unit, University College London Institute of Child Health, London Centre for Pediatric Endocrinology, Great Ormond Street Hospital for Children, London, UK
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14
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Ko JS, Moon JS, Seo JK, Yang HR, Chang JY, Park SS. A mutation analysis of the AGL gene in Korean patients with glycogen storage disease type III. J Hum Genet 2013; 59:42-5. [PMID: 24257475 DOI: 10.1038/jhg.2013.117] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 09/20/2013] [Accepted: 09/27/2013] [Indexed: 11/09/2022]
Abstract
Glycogen storage disease type III (GSD III) is an autosomal recessive disorder that is characterized by the excessive accumulation of abnormal glycogen in the liver and muscles and is caused by a deficiency in glycogen debranching enzyme (amylo-1,6-glucosidase, 4-alpha-glucanotransferase (AGL)) activity. To investigate the molecular characteristics of GSD III patients in Korea, we have sequenced the AGL gene in eight children with GSD III. All patients were compound heterozygotes. We identified 10 different mutations (five novel and five previously reported). The novel mutations include one nonsense (c.1461G>A, p.W487X), three splicing (c.293+4_293+6delAGT in IVS4, c.460+1G>T in IVS5, c.2682-8A>G in IVS21) and one missense mutation (c.2591G>C, p.R864P). Together, p.R285X, c.1735+1G>T and p.L1139P accounted for 56% of all alleles, while the remaining mutations are heterogeneous. These three mutations can be common in Korea, and further larger studies are needed to confirm our findings.
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Affiliation(s)
- Jae Sung Ko
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Jin Soo Moon
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Jeong Kee Seo
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Hye Ran Yang
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Ju Young Chang
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Sung Sup Park
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
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Ben Rhouma F, Azzouz H, Petit FM, Khelifa MB, Chehida AB, Nasrallah F, Parisot F, Lasram K, Kefi R, Bouyacoub Y, Romdhane L, Baussan C, Kaabachi N, Ben Dridi MF, Tebib N, Abdelhak S. Molecular and biochemical characterization of a novel intronic single point mutation in a Tunisian family with glycogen storage disease type III. Mol Biol Rep 2013; 40:4197-202. [PMID: 23649758 DOI: 10.1007/s11033-013-2500-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 04/27/2013] [Indexed: 10/26/2022]
Abstract
Genetic deficiency of the glycogen debranching enzyme causes glycogen storage disease type III, an autosomal recessive inherited disorder. The gene encoding this enzyme is designated as AGL gene. The disease is characterized by fasting hypoglycemia, hepatomegaly, growth retardation, progressive myopathy and cardiomyopathy. In the present study, we present clinical features and molecular characterization of two consanguineous Tunisian siblings suffering from Glycogen storage disease type III. The full coding exons of the AGL gene and their corresponding exon-intron boundaries were amplified for the patients and their parents. Gene sequencing identified a novel single point mutation at the conserved polypyrimidine tract of intron 21 in a homozygous state (IVS21-8A>G). This variant cosegregated with the disease and was absent in 102 control chromosomes. In silico analysis using online resources showed a decreased score of the acceptor splice site of intron 21. RT-PCR analysis of the AGL splicing pattern revealed a 7 bp sequence insertion between exon 21 and exon 22 due to the creation of a new 3' splice site. The predicted mutant enzyme was truncated by the loss of 637 carboxyl-terminal amino acids as a result of premature termination. This novel mutation is the first mutation identified in the region of Bizerte and the tenth AGL mutation identified in Tunisia. Screening for this mutation can improve the genetic counseling and prenatal diagnosis of GSD III.
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Affiliation(s)
- Faten Ben Rhouma
- Laboratoire de Genomique Biomedicale et Oncogenetique LR11IPT05, Institut Pasteur de Tunis, 1002, Tunis, Tunisia
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16
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Dingerdissen H, Motwani M, Karagiannis K, Simonyan V, Mazumder R. Proteome-wide analysis of nonsynonymous single-nucleotide variations in active sites of human proteins. FEBS J 2013; 280:1542-62. [PMID: 23350563 DOI: 10.1111/febs.12155] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 12/13/2012] [Accepted: 01/17/2013] [Indexed: 12/30/2022]
Abstract
An enzyme's active site is essential to normal protein activity such that any disruptions at this site may lead to dysfunction and disease. Nonsynonymous single-nucleotide variations (nsSNVs), which alter the amino acid sequence, are one type of disruption that can alter the active site. When this occurs, it is assumed that enzyme activity will vary because of the criticality of the site to normal protein function. We integrate nsSNV data and active site annotations from curated resources to identify all active-site-impacting nsSNVs in the human genome and search for all pathways observed to be associated with this data set to assess the likely consequences. We find that there are 934 unique nsSNVs that occur at the active sites of 559 proteins. Analysis of the nsSNV data shows an over-representation of arginine and an under-representation of cysteine, phenylalanine and tyrosine when comparing the list of nsSNV-impacted active site residues with the list of all possible proteomic active site residues, implying a potential bias for or against variation of these residues at the active site. Clustering analysis shows an abundance of hydrolases and transferases. Pathway and functional analysis shows several pathways over- or under-represented in the data set, with the most significantly affected pathways involved in carbohydrate metabolism. We provide a table of 32 variation-substrate/product pairs that can be used in targeted metabolomics experiments to assay the effects of specific variations. In addition, we report the significant prevalence of aspartic acid to histidine variation in eight proteins associated with nine diseases including glycogen storage diseases, lacrimo-auriculo-dento-digital syndrome, Parkinson's disease and several cancers.
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Affiliation(s)
- Hayley Dingerdissen
- Department of Biochemistry and Molecular Biology, George Washington University Medical Center, Washington, DC 20037, USA
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Senniappan S, Arya VB, Hussain K. The molecular mechanisms, diagnosis and management of congenital hyperinsulinism. Indian J Endocrinol Metab 2013; 17:19-30. [PMID: 23776849 PMCID: PMC3659902 DOI: 10.4103/2230-8210.107822] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Congenital hyperinsulinism (CHI) is the result of unregulated insulin secretion from the pancreatic β-cells leading to severe hypoglycaemia. In these patients it is important to make an accurate diagnosis and initiate the appropriate management so as to avoid hypoglycemic episodes and prevent the potentially associated complications like epilepsy, neurological impairment and cerebral palsy. At a genetic level abnormalities in eight different genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, HNF4A and UCP2) have been reported with CHI. Loss of function mutations in ABCC8/KCNJ11 lead to the most severe forms of CHI which are usually medically unresponsive. At a histological level there are two major subgroups, diffuse and focal, each with a different genetic etiology. The focal form is sporadic in inheritance and is localized to a small region of the pancreas whereas the diffuse form is inherited in an autosomal recessive (or dominant) manner. Imaging using a specialized positron emission tomography scan with the isotope fluroine-18 L-3, 4-dihydroxyphenyalanine (18F-DOPA-PET-CT) is used to accurately locate the focal lesion pre-operatively and if removed can cure the patient from hypoglycemia. Understanding the molecular mechanisms, the histological basis, improvements in imaging modalities and surgical techniques have all improved the management of patients with CHI.
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Affiliation(s)
- Senthil Senniappan
- Department of Pediatric Endocrinology, Great Ormond Street Hospital for Children NHS Trust WC1N 3JH and Institute of Child Health, University College London, WC1N 1EH, United Kingdom
| | - Ved Bhushan Arya
- Department of Pediatric Endocrinology, Great Ormond Street Hospital for Children NHS Trust WC1N 3JH and Institute of Child Health, University College London, WC1N 1EH, United Kingdom
| | - Khalid Hussain
- Department of Pediatric Endocrinology, Great Ormond Street Hospital for Children NHS Trust WC1N 3JH and Institute of Child Health, University College London, WC1N 1EH, United Kingdom
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Romdhane L, Kefi R, Azaiez H, Ben Halim N, Dellagi K, Abdelhak S. Founder mutations in Tunisia: implications for diagnosis in North Africa and Middle East. Orphanet J Rare Dis 2012; 7:52. [PMID: 22908982 PMCID: PMC3495028 DOI: 10.1186/1750-1172-7-52] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 08/02/2012] [Indexed: 01/17/2023] Open
Abstract
Background Tunisia is a North African country of 10 million inhabitants. The native background population is Berber. However, throughout its history, Tunisia has been the site of invasions and migratory waves of allogenic populations and ethnic groups such as Phoenicians, Romans, Vandals, Arabs, Ottomans and French. Like neighbouring and Middle Eastern countries, the Tunisian population shows a relatively high rate of consanguinity and endogamy that favor expression of recessive genetic disorders at relatively high rates. Many factors could contribute to the recurrence of monogenic morbid trait expression. Among them, founder mutations that arise in one ancestral individual and diffuse through generations in isolated communities. Method We report here on founder mutations in the Tunisian population by a systematic review of all available data from PubMed, other sources of the scientific literature as well as unpublished data from our research laboratory. Results We identified two different classes of founder mutations. The first includes founder mutations so far reported only among Tunisians that are responsible for 30 genetic diseases. The second group represents founder haplotypes described in 51 inherited conditions that occur among Tunisians and are also shared with other North African and Middle Eastern countries. Several heavily disabilitating diseases are caused by recessive founder mutations. They include, among others, neuromuscular diseases such as congenital muscular dystrophy and spastic paraglegia and also severe genodermatoses such as dystrophic epidermolysis bullosa and xeroderma pigmentosa. Conclusion This report provides informations on founder mutations for 73 genetic diseases either specific to Tunisians or shared by other populations. Taking into account the relatively high number and frequency of genetic diseases in the region and the limited resources, screening for these founder mutations should provide a rapid and cost effective tool for molecular diagnosis. Indeed, our report should help designing appropriate measures for carrier screening, better evaluation of diseases burden and setting up of preventive measures at the regional level.
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Affiliation(s)
- Lilia Romdhane
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, BP 74, 13 Place Pasteur, Tunis 1002, Tunisia
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