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Abstract
PURPOSE Enzyme replacement therapy with alglucosidase alfa for infantile Pompe disease has improved survival creating new management challenges. We describe an emerging phenotype in a retrospective review of long-term survivors. METHODS Inclusion criteria included ventilator-free status and age ≤6 months at treatment initiation, and survival to age ≥5 years. Clinical outcome measures included invasive ventilator-free survival and parameters for cardiac, pulmonary, musculoskeletal, gross motor, and ambulatory status; growth; speech, hearing, and swallowing; and gastrointestinal and nutritional status. RESULTS Eleven of 17 patients met study criteria. All were cross-reactive immunologic material-positive, alive, and invasive ventilator-free at most recent assessment, with a median age of 8.0 years (range: 5.4-12.0 years). All had marked improvements in cardiac parameters. Commonly present were gross motor weakness, motor speech deficits, sensorineural and/or conductive hearing loss, osteopenia, gastroesophageal reflux, and dysphagia with aspiration risk. Seven of 11 patients were independently ambulatory and four required the use of assistive ambulatory devices. All long-term survivors had low or undetectable anti-alglucosidase alfa antibody titers. CONCLUSION Long-term survivors exhibited sustained improvements in cardiac parameters and gross motor function. Residual muscle weakness, hearing loss, risk for arrhythmias, hypernasal speech, dysphagia with risk for aspiration, and osteopenia were commonly observed findings.
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Newborn screening for lysosomal storage disorders in hungary. JIMD Rep 2012; 6:117-25. [PMID: 23430949 DOI: 10.1007/8904_2012_130] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 02/02/2012] [Accepted: 02/06/2012] [Indexed: 12/18/2022] Open
Abstract
Even though lysosomal storage disorders (LSDs) are considered to be orphan diseases, they pose a highly relevant cause for morbidity and mortality as their cumulative prevalence is estimated to be 1:4,000. This is especially important as treatment in form of enzyme replacement therapy, substrate reduction therapy or stem cell transplantation is amenable for some LSDs. It is plausible that an early start of treatment might improve the overall prognosis and, even more important, prevent irreversible damage of key organs. To get a more precise insight into the real frequency of some LSDs in the general population, we screened 40,024 samples from the Hungarian newborn screening (NBS) program in Szeged for Fabry disease (FD), Gaucher disease (GD), Pompe disease (PD), and Niemann-Pick A/B (NPB) disease using tandem mass spectrometry. Altogether, 663 samples (1.66%) were submitted for retesting. Genetic confirmation was carried out for 120 samples with abnormal screening results after retesting, which identified three cases of GD, three cases of FD, nine cases of PD, and two cases with NPB. In some cases, we detected up to now unknown mutations - one in NPB and seven in PD - which raise questions about the clinical consequences of a NBS in the sense of late-onset manifestations. Overall, we conclude that screening for LSDs by tandem MS/MS followed by a genetic workup in identified patients is a robust, easy, valid, and feasible technology in newborn screening programs. Furthermore, early diagnosis of LSDs gives a chance to early treatment, but needs more clinical long-term data especially regarding the consequence of private mutations.
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Furusawa Y, Mori-Yoshimura M, Yamamoto T, Sakamoto C, Wakita M, Kobayashi Y, Fukumoto Y, Oya Y, Fukuda T, Sugie H, Hayashi YK, Nishino I, Nonaka I, Murata M. Effects of enzyme replacement therapy on five patients with advanced late-onset glycogen storage disease type II: a 2-year follow-up study. J Inherit Metab Dis 2012; 35:301-10. [PMID: 21984055 DOI: 10.1007/s10545-011-9393-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 09/04/2011] [Accepted: 09/08/2011] [Indexed: 11/29/2022]
Abstract
We examined the efficacy of 2-year enzyme replacement therapy (ERT) using recombinant human α-glucosidase (GAA; Myozyme®) in five long-term ventilator-dependent adults and aged patients with advanced, late-onset glycogen storage disease type II (GSDII, also known as Pompe disease). Although all patients had advanced respiratory failure and were ventilator-dependent for more than 6 years, four showed obvious improvements in muscle strength, pulmonary function, and activities of daily living after ERT. Improvement in each parameter was more prominent in the first year than in the second year. Values in the second year were still significantly better than those at study entry and indicate stabilization in the clinical status of all patients. These results suggest that ERT continues to be effective in the second year of treatment even in patients suffering from advanced late-onset GSDII disease with severe respiratory failure.
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Affiliation(s)
- Yoshihiko Furusawa
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi-cho, Kodaira, Tokyo, 187-8551, Japan
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Ebrahim HY, Baker RJ, Mehta AB, Hughes DA. Functional analysis of variant lysosomal acid glycosidases of Anderson-Fabry and Pompe disease in a human embryonic kidney epithelial cell line (HEK 293 T). J Inherit Metab Dis 2012; 35:325-34. [PMID: 21972175 DOI: 10.1007/s10545-011-9395-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Revised: 09/05/2011] [Accepted: 09/08/2011] [Indexed: 11/30/2022]
Abstract
The functional significance of missense mutations in genes encoding acid glycosidases of lysosomal storage disorders (LSDs) is not always clear. Here we describe a method of investigating functional properties of variant enzymes in vitro using a human embryonic kidney epithelial cell line. Site-directed mutagenesis was performed on the parental plasmids containing cDNA encoding for alpha-galactosidase A (α-Gal A) and acid maltase (α-Glu) to prepare plasmids encoding relevant point mutations. Mutant plasmids were transfected into HEK 293 T cells, and transient over-expression of variant enzymes was measured after 3 days. We have illustrated the method by examining enzymatic activities of four unknown α-Gal A and one α-Glu variants identified in our patients with Anderson-Fabry disease and Pompe diseases respectively. Comparison with control variants known to be either pathogenic or non-pathogenic together with over-expression of wild-type enzyme allowed determination of the pathogenicity of the mutation. One leader sequence novel variant of α-Gal A (p.A15T) was shown not to significantly reduce enzyme activity, whereas three other novel α-Gal A variants (p.D93Y, p.L372P and p.T410I) were shown to be pathogenic as they resulted in significant reduction of enzyme activity. A novel α-Glu variant (p.L72R) was shown to be pathogenic as this significantly reduced enzyme activity. Certain acid glycosidase variants that have been described in association with late-onset LSDs and which are known to have variable residual plasma and leukocyte enzyme activity in patients appear to show intermediate to low enzyme activity (p.N215S and p.Q279E α-Gal A respectively) in the over-expression system.
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Affiliation(s)
- Hatim Y Ebrahim
- Department of Haematology, Royal Free Campus, University College London Medical School, Rowland Hill Street, London, NW3 2PF, UK
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55
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Kroos M, Hoogeveen-Westerveld M, van der Ploeg A, Reuser AJ. The genotype-phenotype correlation in Pompe disease. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2012; 160C:59-68. [DOI: 10.1002/ajmg.c.31318] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Bali DS, Goldstein JL, Banugaria S, Dai J, Mackey J, Rehder C, Kishnani PS. Predicting cross-reactive immunological material (CRIM) status in Pompe disease using GAA mutations: lessons learned from 10 years of clinical laboratory testing experience. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2012; 160C:40-9. [PMID: 22252923 DOI: 10.1002/ajmg.c.31319] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Enzyme replacement therapy (ERT) for Pompe disease using recombinant acid alpha-glucosidase (rhGAA) has resulted in increased survival although the clinical response is variable. Cross-reactive immunological material (CRIM)-negative status has been recognized as a poor prognostic factor. CRIM-negative patients make no GAA protein and develop sustained high antibody titers to ERT that render the treatment ineffective. Antibody titers are generally low for the majority of CRIM-positive patients and there is typically a better clinical outcome. Because immunomodulation has been found to be most effective in CRIM-negative patients prior to, or shortly after, initiation of ERT, knowledge of CRIM status is important before ERT is begun. We have analyzed 243 patients with infantile Pompe disease using a Western blot method for determining CRIM status and using cultured skin fibroblasts. Sixty-one out of 243 (25.1%) patients tested from various ethnic backgrounds were found to be CRIM-negative. We then correlated the CRIM results with GAA gene mutations where available (52 CRIM-negative and 88 CRIM-positive patients). We found that, in most cases, CRIM status can be predicted from GAA mutations, potentially circumventing the need for invasive skin biopsy and time wasted in culturing cells in the future. Continued studies in this area will help to increase the power of GAA gene mutations in predicting CRIM status as well as possibly identifying CRIM-positive patients who are at risk for developing high antibody titers.
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Affiliation(s)
- Deeksha S Bali
- Duke Biochemical Genetics Laboratory, Durham, NC 27713, USA.
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Schüller A, Wenninger S, Strigl-Pill N, Schoser B. Toward deconstructing the phenotype of late-onset Pompe disease. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2012; 160C:80-8. [DOI: 10.1002/ajmg.c.31322] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Rosales XQ, al-Dahhak R, Tsao CY. Childhood onset of limb-girdle muscular dystrophy. Pediatr Neurol 2012; 46:13-23. [PMID: 22196486 DOI: 10.1016/j.pediatrneurol.2011.08.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 08/25/2011] [Indexed: 01/16/2023]
Abstract
Limb-girdle muscular dystrophies comprise a rare heterogeneous group of genetic muscular dystrophies, involving 15 autosomal recessive subtypes and seven autosomal dominant subtypes. Autosomal recessive dystrophy is far more common than autosomal dominant dystrophy. Typical clinical features include progressive limb muscle weakness and atrophy (proximal greater than distal), varying from very mild to severe. Significant overlap of clinical phenotypes, with genetic and clinical heterogeneity, constitutes the rule for this group of diseases. Muscle biopsies are useful for histopathologic and immunolabeling studies, and DNA analysis is the gold standard to establish the specific form of muscular dystrophy. A definitive diagnosis among various subtypes is challenging, and the data presented here provide neuromuscular clinicians with additional information to help attain that goal.
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Affiliation(s)
- Xiomara Q Rosales
- Neuromuscular Division, Department of Pediatrics, Nationwide Children's Hospital, Columbus, Ohio, USA
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59
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Yang CC, Chien YH, Lee NC, Chiang SC, Lin SP, Kuo YT, Chen SS, Jong YJ, Hwu WL. Rapid progressive course of later-onset Pompe disease in Chinese patients. Mol Genet Metab 2011; 104:284-8. [PMID: 21757382 DOI: 10.1016/j.ymgme.2011.06.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 06/14/2011] [Indexed: 11/20/2022]
Abstract
BACKGROUND Pompe disease presents with a wide variety of phenotypes ranging from a fatal disease in infancy (the infantile-onset form) to other milder later-onset forms. Currently, the clinical manifestations in Chinese patients with later-onset Pompe disease are still not well understood. METHODS Fifteen Chinese patients who were clinically diagnosed with Pompe disease at later than one year of age at the National Taiwan University Hospital from 1993 to 2009 were included in this study. Confirmatory diagnosis included both biochemical and molecular tests. Patient outcomes after recombinant human acid α-glucosidase (GAA) therapy were also evaluated by assessing the percentage of predicted forced vital capacity in the upright position, hours of daily ventilator use, and the functional status change using Walton Gardner Medwin Scale. RESULTS The median age at symptom onset was 15 (12-35)years, and the median age at diagnosis was 21 (10-38)years. At the time of diagnosis or shortly after, 8 patients (53%) required mechanical ventilation. A quadriceps muscle biopsy from a 13-year-old boy already showed extensive glycogen storage and muscle fiber destruction. Mutation analysis revealed that the two dual mutations in the GAA gene c.[1935C>A; 1726G>A] (p.[D645E; G576S]) and c.[2238G>C; 1726G>A] (p.[W746C; G576S]) represented 66.5% of the mutated chromosomes. Using mutagenesis, we showed that the p.G576S pseudodeficiency mutation significantly decreased the residual enzyme activity of p.W746C. Most patients responded poorly to recombinant human GAA. CONCLUSIONS Chinese patients with later-onset Pompe disease often showed onset of symptoms in their second decade of life with rapid disease progression, which is probably due to a specific pattern of GAA gene mutation. Therefore, early diagnosis and early treatment would be necessary to improve the prognosis of these patients.
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Affiliation(s)
- Chih-Chao Yang
- Department of Neurology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
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60
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Proteasome inhibitors improve the function of mutant lysosomal α-glucosidase in fibroblasts from Pompe disease patient carrying c.546G>T mutation. Biochem Biophys Res Commun 2011; 415:274-8. [PMID: 22027144 DOI: 10.1016/j.bbrc.2011.10.038] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Accepted: 10/11/2011] [Indexed: 11/20/2022]
Abstract
Pompe disease (glycogen storage disease type II) is an autosomal recessive myopathic disorder arising from the deficiency of lysosomal acid α-glucosidase (GAA). Recently, we found that mutant GAA in patient fibroblasts carrying c.546G>T mutation is stabilized by treatment with proteasome inhibitor as well as pharmacological chaperon N-butyl-deoxynojirimycin. In this study, we characterized the effect of two proteasome inhibitors, bortezomib and MG132, on maturation, subcellular localization and residual activity of mutant GAA in the patient fibroblasts carrying c.546G>T mutation. Each proteasome inhibitor promoted the stabilization of patient GAA and processing of them to mature forms without cytotoxic effect. Immunocytochemical analysis showed increased colocalization of GAA with the lysosomal marker LAMP2 in patient fibroblasts treated with proteasome inhibitors. Furthermore, bortezomib and MG132 also increased enzyme activity in the patient fibroblasts (about 4-fold and 2-fold, respectively). These findings indicate that proteasome inhibitor may be a novel drug as potential pharmacological chaperone therapy for Pompe disease patient carrying chaperon-responsive mutation.
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61
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Dimauro S, Garone C. Metabolic disorders of fetal life: glycogenoses and mitochondrial defects of the mitochondrial respiratory chain. Semin Fetal Neonatal Med 2011; 16:181-9. [PMID: 21620786 DOI: 10.1016/j.siny.2011.04.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Two major groups of inborn errors of energy metabolism are reviewed -glycogenoses and defects of the mitochondrial respiratory chain - to see how often these disorders present in fetal life or neonatally. After some general considerations on energy metabolism in the pre- and postnatal development of the human infant, different glycogen storage diseases and mitochondrial encephalomyopathies are surveyed. General conclusions are that: (i) disorders of glycogen metabolism are more likely to cause 'fetal disease' than defects of the respiratory chain; (ii) mitochondrial encephalomyopathies, especially those due to defects of the nuclear genome, are frequent causes of neonatal or infantile diseases, typically Leigh syndrome, but usually do not cause fetal distress; (iii) notable exceptions include mutations in the complex III assembly gene BCS1L resulting in the GRACILE syndrome (growth retardation, aminoaciduria, cholestasis, iron overload, lactic acidosis, and early death), and defects of mitochondrial protein synthesis, which are the 'new frontier' in mitochondrial translational research.
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Affiliation(s)
- S Dimauro
- Department of Neurology, Columbia University Medical Center, New York, NY, USA.
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62
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Bali DS, Tolun AA, Goldstein JL, Dai J, Kishnani PS. Molecular analysis and protein processing in late-onset pompe disease patients with low levels of acid α-glucosidase activity. Muscle Nerve 2011; 43:665-70. [DOI: 10.1002/mus.21933] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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63
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Biochemical and structural study on a S529V mutant acid α-glucosidase responsive to pharmacological chaperones. J Hum Genet 2011; 56:440-6. [PMID: 21471980 DOI: 10.1038/jhg.2011.36] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recently, pharmacological chaperone therapy for Pompe disease with small molecules such as imino sugars has attracted interest. But mutant acid α-glucosidase (GAA) species responsive to imino sugars are limited. To elucidate the characteristics of a mutant GAA responsive to imino sugars, we performed biochemical and structural analyses. Among cultured fibroblast cell lines derived from Japanese Pompe patients, only one carrying p.S529V/p.S619R amino acid substitutions responded to 1-deoxynojirimycin (DNJ), and an expression study revealed that DNJ, N-butyl-deoxynojirimycin and nojirimycin-1-sulfonic acid increased the enzyme activity of the S529V mutant GAA expressed in Chinese hamster ovary cells. The results of western blotting analysis suggested that these imino sugars facilitated the intracellular transportation of the mutant GAA and stabilized it. Among these imino sugars, DNJ exhibited the strongest action on the mutant GAA. Structural analysis revealed that DNJ almost completely occupied the active site pocket, and interacted with amino acid residues comprising it through van der Waals contacts and hydrogen bonds. This information will be useful for improvement of pharmacological chaperone therapy for Pompe disease.
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DeSena HC, Brumund MR, Superneau D, Snyder CS. Ventricular Fibrillation in a Patient with Pompe Disease: A Cautionary Tale. CONGENIT HEART DIS 2011; 6:397-401. [DOI: 10.1111/j.1747-0803.2010.00471.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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65
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Splicing mutations in glycogen-storage disease type II: evaluation of the full spectrum of mutations and their relation to patients' phenotypes. Eur J Hum Genet 2010; 19:422-31. [PMID: 21179066 DOI: 10.1038/ejhg.2010.188] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Glycogen-storage disease type II is an autosomal recessive-inherited disorder due to the deficiency of acid α-glucosidase. A large number of mutations in the acid α-glucosidase gene have been described to date. Among them, ~15% are variations that may affect mRNA splicing process. In this study, we have for the first time comprehensively reviewed the available information on splicing mutations of the acid α-glucosidase gene and we have evaluated their possible impact on the splicing process using different in silico approaches. Out of the 39 different GAA-sequence variations described, an in silico analysis using seven different programs showed that 97% of them are predicted to have an impact on the splicing process. Moreover, this analysis showed a quite good correlation between the impact of the mutation on the splicing process and the clinical phenotype. In addition, we have performed the functional characterization of three novel sequence variants found in Italian patients and still uncharacterized. Using a minigene system, we have confirmed their pathogenic nature. In conclusion, this study has shown that in silico analysis represents a useful tool to select mutations that affect the splicing process of the acid α-glucosidase gene and provides an updated picture of all this kind of mutations reported till now.
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66
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Marugan JJ, Zheng W, Motabar O, Southall N, Goldin E, Sidransky E, Aungst RA, Liu K, Sadhukhan SK, Austin CP. Evaluation of 2-thioxo-2,3,5,6,7,8-hexahydropyrimido[4,5-d]pyrimidin-4(1H)-one analogues as GAA activators. Eur J Med Chem 2010; 45:1880-97. [PMID: 20206419 PMCID: PMC2892120 DOI: 10.1016/j.ejmech.2010.01.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 01/13/2010] [Accepted: 01/14/2010] [Indexed: 10/19/2022]
Abstract
Pompe disease is a lysosomal storage disease (LSD) caused by a deficiency in the lysosomal enzyme acid alpha-glucosidase. In several LSDs, enzyme inhibitors have been used as small molecule chaperones to facilitate and increase the translocation of mutant protein from the endoplasmic reticulum to the lysosome. Enzyme activators with chaperone activity would be even more desirable as they would not inhibit the enzyme after translocation and might potentiate the activity of the enzyme that is successfully translocated. Herein we report our initial findings of a new series of acid alpha-glucosidase activators.
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Affiliation(s)
- Juan J Marugan
- NIH Chemical Genomic Center, National Human Genome Research Institute, National Institutes of Heath, 9800 Medical Center Drive, Rockville, MD, USA.
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Flanagan JJ, Rossi B, Tang K, Wu X, Mascioli K, Donaudy F, Tuzzi MR, Fontana F, Cubellis MV, Porto C, Benjamin E, Lockhart DJ, Valenzano KJ, Andria G, Parenti G, Do HV. The pharmacological chaperone 1-deoxynojirimycin increases the activity and lysosomal trafficking of multiple mutant forms of acid alpha-glucosidase. Hum Mutat 2009; 30:1683-92. [DOI: 10.1002/humu.21121] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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68
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Silent exonic mutation in the acid-alpha-glycosidase gene that causes glycogen storage disease type II by affecting mRNA splicing. J Hum Genet 2009; 54:493-6. [PMID: 19609281 DOI: 10.1038/jhg.2009.66] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Glycogen-storage disease type II (GSDII) is an autosomal recessive disorder caused by a deficiency of acid alpha-glucosidase (GAA). The residual GAA activity is largely related to the severity of the clinical course. Most patients with infantile-onset GSDII do not show any enzyme activity, whereas patients with the late-onset forms of GSDII show various degrees of GAA activity. We performed a molecular genetic study on a Japanese boy with childhood-onset GSDII. The patient was a compound heterozygote for a newly discovered splice-site c.546G>T mutation and a recurrent missense p.R600C mutation, which usually causes the fatal infantile form in a homozygous state. The c.546G>T mutation, which did not alter the amino-acid sequence, was positioned at the last base of exon 2. cDNA-sequencing analysis revealed that c.546G>T was a leaky splice mutation, leading to the production of a normally spliced transcript, which was responsible for the low-level (approximately 10%) expression of the active enzyme in the patient's fibroblasts.
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69
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Korpela MP, Paetau A, Löfberg MI, Timonen MH, Lamminen AE, Kiuru-Enari SM. A novel mutation of the GAA gene in a Finnish late-onset pompe disease patient: Clinical phenotype and follow-up with enzyme replacement therapy. Muscle Nerve 2009; 40:143-8. [DOI: 10.1002/mus.21291] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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70
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Porto C, Cardone M, Fontana F, Rossi B, Tuzzi MR, Tarallo A, Barone MV, Andria G, Parenti G. The pharmacological chaperone N-butyldeoxynojirimycin enhances enzyme replacement therapy in Pompe disease fibroblasts. Mol Ther 2009; 17:964-71. [PMID: 19293774 PMCID: PMC2835191 DOI: 10.1038/mt.2009.53] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Accepted: 02/20/2009] [Indexed: 02/08/2023] Open
Abstract
In spite of the progress in the treatment of lysosomal storage diseases (LSDs), in some of these disorders the available therapies show limited efficacy and a need exists to identify novel therapeutic strategies. We studied the combination of enzyme replacement and enzyme enhancement by pharmacological chaperones in Pompe disease (PD), a metabolic myopathy caused by the deficiency of the lysosomal acid alpha-glucosidase. We showed that coincubation of Pompe fibroblasts with recombinant human alpha-glucosidase and the chaperone N-butyldeoxynojirimycin (NB-DNJ) resulted in more efficient correction of enzyme activity. The chaperone improved alpha-glucosidase delivery to lysosomes, enhanced enzyme maturation, and increased enzyme stability. Improved enzyme correction was also found in vivo in a mouse model of PD treated with coadministration of single infusions of recombinant human alpha-glucosidase and oral NB-DNJ. The enhancing effect of chaperones on recombinant enzymes was also observed in fibroblasts from another lysosomal disease, Fabry disease, treated with recombinant alpha-galactosidase A and the specific chaperone 1-deoxygalactonojirimycin (DGJ). These results have important clinical implications, as they demonstrate synergy between pharmacological chaperones and enzyme replacement. A synergistic effect of these treatments may result particularly useful in patients responding poorly to therapy and in tissues in which sufficient enzyme levels are difficult to obtain.
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Affiliation(s)
- Caterina Porto
- Department of Pediatrics, Federico II University, Naples, Italy
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71
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Motabar O, Shi ZD, Goldin E, Liu K, Southall N, Sidransky E, Austin CP, Griffiths GL, Zheng W. A new resorufin-based alpha-glucosidase assay for high-throughput screening. Anal Biochem 2009; 390:79-84. [PMID: 19371716 DOI: 10.1016/j.ab.2009.04.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 04/07/2009] [Accepted: 04/09/2009] [Indexed: 12/20/2022]
Abstract
Mutations in alpha-glucosidase cause accumulation of glycogen in lysosomes, resulting in Pompe disease, a lysosomal storage disorder. Small molecule chaperones that bind to enzyme proteins and correct the misfolding and mistrafficking of mutant proteins have emerged as a new therapeutic approach for the lysosomal storage disorders. In addition, alpha-glucosidase is a therapeutic target for type II diabetes, and alpha-glucosidase inhibitors have been used in the clinic as alternative treatments for this disease. We have developed a new fluorogenic substrate for the alpha-glucosidase enzyme assay, resorufin alpha-d-glucopyranoside. The enzyme reaction product of this new substrate emits at a peak of 590 nm, reducing the interference from fluorescent compounds seen with the existing fluorogenic substrate, 4-methylumbelliferyl-alpha-D-glucopyranoside. Also, the enzyme kinetic assay can be carried out continuously without the addition of stop solution due to the lower pK(a) of the product of this substrate. Therefore, this new fluorogenic substrate is a useful tool for the alpha-glucosidase enzyme assay and will facilitate compound screening for the development of new therapies for Pompe disease.
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Affiliation(s)
- Omid Motabar
- NIH Chemical Genomics Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Sugawara K, Saito S, Sekijima M, Ohno K, Tajima Y, Kroos MA, Reuser AJJ, Sakuraba H. Structural modeling of mutant alpha-glucosidases resulting in a processing/transport defect in Pompe disease. J Hum Genet 2009; 54:324-30. [PMID: 19343043 DOI: 10.1038/jhg.2009.32] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
To elucidate the mechanism underlying transport and processing defects from the viewpoint of enzyme folding, we constructed three-dimensional models of human acid alpha-glucosidase encompassing 27 relevant amino acid substitutions by means of homology modeling. Then, we determined in each separate case the number of affected atoms, the root-mean-square distance value and the solvent-accessible surface area value. The analysis revealed that the amino acid substitutions causing a processing or transport defect responsible for Pompe disease were widely spread over all of the five domains comprising the acid alpha-glucosidase. They were distributed from the core to the surface of the enzyme molecule, and the predicted structural changes varied from large to very small. Among the structural changes, we paid particular attention to G377R and G483R. These two substitutions are predicted to cause electrostatic changes in neighboring small regions on the molecular surface. The quality control system of the endoplasmic reticulum apparently detects these very small structural changes and degrades the mutant enzyme precursor (G377R), but also the cellular sorting system might be misled by these minor changes whereby the precursor is secreted instead of being transported to lysosomes (G483R).
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Affiliation(s)
- Kanako Sugawara
- Department of Analytical Biochemistry, Meiji Pharmaceutical University, Tokyo, Japan
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73
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Joshi PR, Gläser D, Schmidt S, Vorgerd M, Winterholler M, Eger K, Zierz S, Deschauer M. Molecular diagnosis of German patients with late-onset glycogen storage disease type II. J Inherit Metab Dis 2008; 31 Suppl 2:S261-5. [PMID: 18607768 DOI: 10.1007/s10545-008-0820-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2007] [Revised: 02/11/2008] [Accepted: 04/22/2008] [Indexed: 11/24/2022]
Abstract
UNLABELLED In patients with late-onset glycogen storage disease type II, one mutation, c.-32-13T>G, in the α-glucosidase (GAA) gene is identified frequently in European populations from different regions along with many rarer mutations. We have performed molecular genetic investigations in 18 German index patients with late-onset disease. The c.-32-13T>G, c.525delT (p.Glu176fsX45), and c.2481+102_2646+31del mutations were detected by PCR/restriction enzyme digest. Other mutations were detected by sequencing. All patients were compound heterozygous and 17 patients harboured the c.-32-13T>G mutation. Seven other previously described mutations (including the c.-32-13T>G) were identified, of which the p.C103G (c.307T>G) and the c.2481+102_2646+31del mutations were present each in three unrelated patients. Sequencing revealed five novel mutations. CONCLUSIONS Genetic testing was able to identify the genetic defects in all patients and screening of the c.-32-13T>G mutation identified 94% of the cases. This is important for quick and reliable diagnosis, especially in view of enzyme replacement. Among the rarer mutations, c.2481+102_2646+31del and p.C103G are rather frequent in Germany.
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Affiliation(s)
- P R Joshi
- Neurologische Universitätsklinik, Halle, Germany.
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74
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Wokke JHJ, Escolar DM, Pestronk A, Jaffe KM, Carter GT, van den Berg LH, Florence JM, Mayhew J, Skrinar A, Corzo D, Laforet P. Clinical features of late-onset Pompe disease: a prospective cohort study. Muscle Nerve 2008; 38:1236-45. [PMID: 18816591 DOI: 10.1002/mus.21025] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The objective of this 12-month study was to describe the clinical features of late-onset Pompe disease and identify appropriate outcome measures for use in clinical trials. Assessments included quantitative muscle testing (QMT), functional activities (FAA), 6-min walk test (6MWT), and pulmonary function testing (PFT). Percent predicted values indicated quantifiable upper and lower extremity weakness, impaired walking ability, and respiratory muscle weakness. Significant declines in arm and leg strength and pulmonary function were observed during the study period. The outcome measures were demonstrated to be safe and reliable. Symptom duration was identified as the best predictor of the extent of skeletal and respiratory muscle weakness.
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Affiliation(s)
- John H J Wokke
- Universitair Medisch Centrum Utrecht HP G03.228, Heidelberglaan 100, 3584 CX Utrecht, Netherlands.
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75
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Abstract
Pompe's disease, glycogen-storage disease type II, and acid maltase deficiency are alternative names for the same metabolic disorder. It is a pan-ethnic autosomal recessive trait characterised by acid alpha-glucosidase deficiency leading to lysosomal glycogen storage. Pompe's disease is also regarded as a muscular disorder, but the generalised storage of glycogen causes more than mobility and respiratory problems. The clinical spectrum is continuous and broad. First symptoms can present in infants, children, and adults. Cardiac hypertrophy is a key feature of classic infantile Pompe's disease. For a long time, there was no means to stop disease progression, but the approval of enzyme replacement therapy has substantially changed the prospects for patients. With this new development, the disease is now among the small but increasing number of lysosomal storage disorders, for which treatment has become a reality. This review is meant to raise general awareness, to present and discuss the latest insights in disease pathophysiology, and to draw attention to new developments about diagnosis and care. We also discuss the developments that led to the approval of enzyme replacement therapy with recombinant human alpha-glucosidase from Chinese hamster ovary cells (alglucosidase alfa) by the US Food and Drug Administration and European Medicines Agency in 2006, and review clinical practice.
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Affiliation(s)
- Ans T van der Ploeg
- Department of Paediatrics, Division of Metabolic Diseases and Genetics, Erasmus MC, Sophia Children's Hospital, University Medical Centre, Rotterdam, The Netherlands.
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76
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Wang J, Lozier J, Johnson G, Kirshner S, Verthelyi D, Pariser A, Shores E, Rosenberg A. Neutralizing antibodies to therapeutic enzymes: considerations for testing, prevention and treatment. Nat Biotechnol 2008; 26:901-8. [PMID: 18688246 PMCID: PMC3478093 DOI: 10.1038/nbt.1484] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Lysosomal storage diseases are characterized by deficiencies in lysosomal enzymes, allowing accumulation of target substrate in cells and eventually causing cell death. Enzyme replacement therapy is the principal treatment for most of these diseases. However, these therapies are often complicated by immune responses to the enzymes, blocking efficacy and causing severe adverse outcomes by neutralizing product activity. It is thus crucial to understand the relationships between genetic mutations, endogenous residual enzyme proteins (cross-reactive immunologic material), development of neutralizing antibodies and their impact on clinical outcomes of lysosomal storage diseases. For patients in whom neutralizing antibodies may cause severe adverse clinical outcomes, it is paramount to develop tolerance inducing protocols to preclude, where predictable, or treat such life-threatening responses.
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Affiliation(s)
- Jinhai Wang
- Division of Therapeutic Proteins, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, NIH Building 29B, 8800 Rockville Pike, Bethesda, Maryland 20892, USA
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77
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Carraresi L, Parini R, Filoni C, Caciotti A, Sersale G, Tomatsu S, Orlando C, Zammarchi E, Guerrini R, Donati MA, Morrone A. GALNS gene expression profiling in Morquio A patients' fibroblasts. Clin Chim Acta 2008; 397:72-6. [PMID: 18710657 DOI: 10.1016/j.cca.2008.07.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Revised: 07/22/2008] [Accepted: 07/22/2008] [Indexed: 12/01/2022]
Abstract
BACKGROUND Quantification studies of mutated mRNAs have not been carried out on Morquio A patients. Such studies are very important for the determination of stability of premature termination codons (PTC) bearing transcripts in order to assess the appropriateness of introducing the newly developed therapeutic strategies such as "stop codon read-through therapy". METHODS This paper focuses on the study of the GALNS gene and mRNAs in two severe forms of Morquio A patients' fibroblasts with development of a new and rapid real-time RT-PCR for detection and quantification of absolute mRNA copy number. RESULTS We identified two new mutations c.385A>T (p.K129X) and c.899-1G>C) in Pt1 and a known splicing defect c.120+1G>A in Pt2. Using RT-PCR and real-time RT-PCR in Pt2 we detected low levels of mRNAs, suggesting its instability; in Pt1, we detected three aberrant mRNAs introducing premature stop codons, suggesting that both the c.385A>T and c.899-1G>C mutations produce mRNAs capable of escaping the nonsense-mediated decay (NMD) pathway. CONCLUSIONS The development of a real-time RT-PCR assay allows to absolutely quantify the GALNS mRNAs carrying mutations that lead to PTCs bearing transcripts, which escape the NMD process and are potentially suitable for the new therapeutic approach.
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Affiliation(s)
- L Carraresi
- Metabolic and Muscular Unit, Clinic of Pediatric Neurology, AOU Meyer, Florence, Italy
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78
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Unbalanced GLA mRNAs ratio quantified by real-time PCR in Fabry patients' fibroblasts results in Fabry disease. Eur J Hum Genet 2008; 16:1311-7. [PMID: 18560446 DOI: 10.1038/ejhg.2008.109] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Total or partial deficiency of the human lysosomal hydrolase alpha-galactosidase A is responsible for Fabry disease, the X-linked inborn error of glycosphingolipid metabolism. Together with the predominant alpha-galactosidase A gene mRNA product encoding the lysosomal enzyme, a weakly regulated alternatively spliced alpha-galactosidase A transcript is expressed in normal tissues, but its overexpression, due to the intronic g.9331G>A mutation, leads to the cardiac variant. We report the molecular characterization of five Fabry patients including two siblings. Sequencing analysis of the alpha-galactosidase A gene coding region and intron/exon boundaries identified the new c.124A>G (p.M42V) genetic lesion as well as a known deletion in three patients, whereas in the two remaining patients, no mutations were identified. To evaluate possible alpha-galactosidase A gene transcription alterations, both predominant and alternatively spliced mRNAs were quantified by absolute real-time PCR on total RNA preparations from the patients' fibroblasts. An impressive reduction in the predominant alpha-galactosidase A transcript was detected in the last patients (Pt 4 and Pt 5). However, the alternatively spliced mRNA was dramatically overexpressed in one of them, carrying a new intronic lesion (g.9273C>T). These findings strongly suggest a correlation between this new intronic mutation and the unbalanced alpha-galactosidase A mRNAs ratio, which could therefore be responsible for the reduced enzyme activity causing Fabry disease. The real-time assay developed here to investigate the two alpha-galactosidase A mRNAs might play a crucial role in revealing possible genetic lesions and in confirming the pathogenetic mechanisms underlying Fabry disease.
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79
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Smith WE, Sullivan-Saarela JA, Li JS, Cox GF, Corzo D, Chen YT, Kishnani PS. Sibling phenotype concordance in classical infantile Pompe disease. Am J Med Genet A 2008; 143A:2493-501. [PMID: 17853454 DOI: 10.1002/ajmg.a.31936] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Pompe disease (acid-alpha-glucosidase deficiency) encompasses a clinical spectrum, ranging from severe infantile-onset disease with clinical symptoms appearing before 1 year of age with rapid progression to an early death, to late-onset disease with a much more variable age at onset and disease course. Sibling phenotype discordance has been reported for late-onset Pompe disease, but has not been studied in classical infantile disease. We reviewed the medical literature for affected sibships in which at least one sibling had clinical and pathology or biochemical findings consistent with infantile Pompe disease including symptoms beginning in infancy, early hypotonia, cardiomegaly documented by 6 months of age, and early death. The age at symptom onset, age at death, and clinical course were compared between probands and affected siblings. Our results showed that since 1931, publications document 13 families with 31 affected infants (11 probands; 20 affected siblings). The median age at symptom onset for all affected infants was 3 months (range 0-6 months) with significant correlation (R = 0.60, P = 0.04) between probands and affected siblings. The median age at death for all affected infants was 6 months (range 1.5-13 months); probands were slightly older at death than their siblings. The median length of disease course for all affected infants was 3 months (0-10 months) and was slightly longer for probands. Unlike late-onset Pompe disease, there appears to be minimal phenotypic and lifespan variation among siblings with infantile Pompe disease. This prognostic information is vital for families with affected infants and allows for appropriate genetic counseling.
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Affiliation(s)
- Wendy E Smith
- Division of Genetics, The Barbara Bush Children's Hospital, Maine Medical Center, Portland, Maine, USA.
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80
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McCready ME, Carson NL, Chakraborty P, Clarke JTR, Callahan JW, Skomorowski MA, Chan AKJ, Bamforth F, Casey R, Rupar CA, Geraghty MT. Development of a clinical assay for detection of GAA mutations and characterization of the GAA mutation spectrum in a Canadian cohort of individuals with glycogen storage disease, type II. Mol Genet Metab 2007; 92:325-35. [PMID: 17723315 DOI: 10.1016/j.ymgme.2007.07.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 07/06/2007] [Accepted: 07/06/2007] [Indexed: 10/22/2022]
Abstract
Glycogen storage disease, type II (GSDII; Pompe disease; acid maltase deficiency) is an autosomal recessive disease caused by mutations of the GAA gene that lead to deficient acid alpha-glucosidase enzyme activity and accumulation of lysosomal glycogen. Although measurement of acid alpha-glucosidase enzyme activity in fibroblasts remains the gold standard for the diagnosis of GSDII, analysis of the GAA gene allows confirmation of clinical or biochemical diagnoses and permits predictive and prenatal testing of individuals at risk of developing GSDII. We have developed a clinical molecular test for the detection of GAA mutations based on cycle sequencing of the complete coding region. GAA exons 2-20 are amplified in six independent PCR using intronic primers. The resulting products were purified and sequenced. Preliminary studies using this protocol were conducted with DNA from 21 GSDII-affected individuals from five centers across Canada. In total, 41 of 42 mutations were detected (96.7% detection rate). Mutations spanned intron 1 through exon 19 and included nine novel mutations. Haplotype analysis of recurrent mutations further suggested that three of these mutations are likely to have occurred independently at least twice. Additionally, we report the identification of the c.-32-13T>G GAA mutation in an individual with infantile variant GSDII, despite reports of this mutation being associated almost exclusively with late-onset forms of the disease. The development of a clinical molecular test provides an important tool for the management and counseling of families and individuals with GSDII, and has provided useful information about the GAA mutation spectrum in Canada.
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Affiliation(s)
- M E McCready
- Children's Hospital of Eastern Ontario, Canada K1H 8L1
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81
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Geel TM, McLaughlin PMJ, de Leij LFMH, Ruiters MHJ, Niezen-Koning KE. Pompe disease: current state of treatment modalities and animal models. Mol Genet Metab 2007; 92:299-307. [PMID: 17826266 DOI: 10.1016/j.ymgme.2007.07.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 07/11/2007] [Accepted: 07/11/2007] [Indexed: 11/23/2022]
Abstract
Pompe disease is a rare autosomal recessive lysosomal storage disease caused by deficiency of acid-alpha-glucosidase (GAA). This deficiency results in glycogen accumulation in the lysosomes, leading to lysosomal swelling, cellular damage and organ dysfunction. In early-onset patients (the classical infantile form and juvenile form) this glycogen accumulation leads to death. The only therapy clinically available is enzyme replacement therapy, which compensates for the missing enzyme by i.v. administration of recombinant produced enzyme. The development of clinically relevant animal models gained more insight in the disease and allowed evaluation of recombinant enzyme therapy. Several therapies are currently under investigation for Pompe disease, including gene therapy. This review gives an overview of the available knockout mouse models, of the in vitro and in vivo studies performed using recombinant produced enzyme. Furthermore, it describes current therapeutic approaches for Pompe disease as well as experimental therapies like gene correction therapy.
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Affiliation(s)
- T M Geel
- Department of Pathology and Laboratory Medicine, Groningen University Institute for Drug Exploration , University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
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82
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Kemper AR, Hwu WL, Lloyd-Puryear M, Kishnani PS. Newborn screening for Pompe disease: synthesis of the evidence and development of screening recommendations. Pediatrics 2007; 120:e1327-34. [PMID: 17974725 DOI: 10.1542/peds.2007-0388] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Pompe disease is a lysosomal storage disorder that leads to the accumulation of glycogen and subsequently to muscle weakness, organ damage, and death. Pompe disease is detectable through newborn screening, and treatment has become available recently. OBJECTIVE Our goal was to review systematically all available evidence regarding screening for infantile Pompe disease to help policy makers determine whether Pompe disease should be added to their state's newborn screening battery. METHODS We searched online databases, including Medline, clinicaltrials.gov, and the Computer Retrieval of Information on Scientific Projects database, as well as Web sites maintained by federal organizations (eg, the Food and Drug Administration) and other nonprofit or private organizations (eg, the March of Dimes and Genzyme Corp), by using the terms "glycogen storage disease type II," "Pompe disease," and "Pompe's disease." We also obtained preliminary findings from a screening program in Taiwan. Data were critically appraised and extracted by 2 investigators, one who is an expert in systematic review methods and the other who is an expert in Pompe disease. RESULTS The prevalence of Pompe disease has been estimated to be approximately 1 case per 40,000. Small studies suggest that enzyme therapy is highly efficacious in infantile Pompe disease and that earlier intervention leads to improved outcomes. Screening cannot distinguish between infantile and late-onset Pompe disease. The current screening program in Taiwan has a high false-positive rate; however, the threshold was purposely set low to ensure that no case would be missed. CONCLUSIONS Pilot studies of screening are needed to identify the most efficacious strategy for screening and determine how to manage cases of late-onset Pompe disease before screening for Pompe disease is adopted widely by newborn screening programs.
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Affiliation(s)
- Alex R Kemper
- Program on Pediatric Health Services Research, Department of Pediatrics, Duke University, Durham, North Carolina, USA.
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83
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Müller-Felber W, Horvath R, Gempel K, Podskarbi T, Shin Y, Pongratz D, Walter MC, Baethmann M, Schlotter-Weigel B, Lochmüller H, Schoser B. Late onset Pompe disease: Clinical and neurophysiological spectrum of 38 patients including long-term follow-up in 18 patients. Neuromuscul Disord 2007; 17:698-706. [PMID: 17643989 DOI: 10.1016/j.nmd.2007.06.002] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 05/28/2007] [Accepted: 06/06/2007] [Indexed: 11/17/2022]
Abstract
To describe the clinical and neurophysiological spectrum and prognosis in a large cohort of biochemically and genetically proven late onset Pompe patients. Thirty-eight diagnosed with late onset Pompe disease at our neuromuscular department during 1985 and 2006 are described in detail. The mean delay from onset of symptoms or first medical consultation until diagnosis was 10.4 and 7.1 years, respectively. A different diagnosis was suggested in 11 of 38 patients. Ten patients underwent repeated muscle biopsies before diagnosis of Pompe disease was established. Limb girdle weakness was the most frequent presenting sign. Six patients complained of myalgia. Wolf-Parkinson-White syndrome was found in 3 of 38 patients. Respiratory failure preceded the onset of overt limb muscle weakness in three patients. The course of the patients was progressive in all, but there was a wide variety of progression, which did not correlate with the age of disease onset. In 71% of the patients, neurophysiological investigations revealed a myopathic EMG pattern, half of the patients had spontaneous activity including complex repetitive discharges. A normal EMG was found in 9% of the patients. Nerve conduction studies were normal in all. Pompe disease should be taken into consideration in patients with unexplained limb girdle muscular weakness with respiratory failure. Cardiac manifestations may not be restricted to infantile Pompe disease.
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Affiliation(s)
- Wolfgang Müller-Felber
- Haunersche Kinderklinik, Childrens Hospital, Ludwig-Maximilians-University, Lindwurmstr. 4, 80337 Munich, Germany.
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84
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Tajima Y, Matsuzawa F, Aikawa SI, Okumiya T, Yoshimizu M, Tsukimura T, Ikekita M, Tsujino S, Tsuji A, Edmunds T, Sakuraba H. Structural and biochemical studies on Pompe disease and a "pseudodeficiency of acid alpha-glucosidase". J Hum Genet 2007; 52:898-906. [PMID: 17805474 DOI: 10.1007/s10038-007-0191-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Accepted: 08/10/2007] [Indexed: 10/22/2022]
Abstract
We constructed structural models of the catalytic domain and the surrounding region of human wild-type acid alpha-glucosidase and the enzyme with amino acid substitutions by means of homology modeling, and examined whether the amino acid replacements caused structural and biochemical changes in the enzyme proteins. Missense mutations including p.R600C, p.S619R and p.R437C are predicted to cause apparent structural changes. Nonsense mutation of p.C103X terminates the translation of acid alpha-glucosidase halfway through its biosynthesis and is deduced not to allow formation of the active site pocket. The mutant proteins resulting from these missense and nonsense mutations found in patients with Pompe disease are predictably unstable and degraded quickly in cells. The structural change caused by p.G576S is predicted to be small, and cells from a subject homozygous for this amino acid substitution exhibited 15 and 11% of the normal enzyme activity levels for an artificial substrate and glycogen, respectively, and corresponding amounts of the enzyme protein on Western blotting. No accumulation of glycogen was found in organs including skeletal muscle in the subject, and thus the residual enzyme activity could protect cells from glycogen storage. On the other hand, p.E689K, which is known as a neutral polymorphism, little affected the three-dimensional structure of acid alpha-glucosidase. Structural study on a mutant acid alpha-glucosidase in silico combined with biochemical investigation is useful for understanding the molecular pathology of Pompe disease.
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Affiliation(s)
- Youichi Tajima
- Department of Clinical Genetics, The Tokyo Metropolitan Institute of Medical Science, Tokyo Metropolitan Organization for Medical Research, Tokyo, Japan
| | - Fumiko Matsuzawa
- Department of Clinical Genetics, The Tokyo Metropolitan Institute of Medical Science, Tokyo Metropolitan Organization for Medical Research, Tokyo, Japan
| | - Sei-Ichi Aikawa
- Department of Clinical Genetics, The Tokyo Metropolitan Institute of Medical Science, Tokyo Metropolitan Organization for Medical Research, Tokyo, Japan
| | - Toshika Okumiya
- Department of Analytical Biochemistry, School of Health Sciences, Kumamoto University, Kumamoto, Japan
| | - Michiru Yoshimizu
- Department of Clinical Genetics, The Tokyo Metropolitan Institute of Medical Science, Tokyo Metropolitan Organization for Medical Research, Tokyo, Japan
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Japan
| | - Takahiro Tsukimura
- Department of Clinical Genetics, The Tokyo Metropolitan Institute of Medical Science, Tokyo Metropolitan Organization for Medical Research, Tokyo, Japan
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Japan
| | - Masahiko Ikekita
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Japan
| | - Seiichi Tsujino
- Department of Peripheral Nervous System Research, National Institute of Neuroscience, NCNP, Kodaira, Japan
| | - Akihiko Tsuji
- Department of Biological Science and Technology, Faculty of Engineering, University of Tokushima, Tokushima, Japan
| | | | - Hitoshi Sakuraba
- Department of Clinical Genetics, The Tokyo Metropolitan Institute of Medical Science, Tokyo Metropolitan Organization for Medical Research, Tokyo, Japan.
- Department of Analytical Biochemistry, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan.
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85
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Gort L, Coll MJ, Chabás A. Glycogen storage disease type II in Spanish patients: high frequency of c.1076-1G>C mutation. Mol Genet Metab 2007; 92:183-7. [PMID: 17616415 DOI: 10.1016/j.ymgme.2007.05.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 05/24/2007] [Accepted: 05/24/2007] [Indexed: 11/22/2022]
Abstract
Glycogen storage disease type II is an autosomal recessive disorder of glycogen metabolism due to deficiency of lysosomal acid alpha-glucosidase. We present the molecular and enzymatic analyses of 22 Spanish GSD II patients. Molecular analyses revealed nine novel mutations. The most common defects were mutations c.-32-13T>G (25%) and c.1076-1G>C (14%) and we report the first homozygous patient for c.1076-1G>C mutation presenting with an infantile form. Alleles bearing mutation c.-32-13T>G are associated with the same haplotype.
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Affiliation(s)
- Laura Gort
- Institut de Bioquímica Clínica, Hospital Clínic, C/ Mejía Lequerica s/n, Edifici Helios III, 08028 Barcelona, Spain
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86
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Hawes ML, Kennedy W, O'Callaghan MW, Thurberg BL. Differential muscular glycogen clearance after enzyme replacement therapy in a mouse model of Pompe disease. Mol Genet Metab 2007; 91:343-51. [PMID: 17572127 DOI: 10.1016/j.ymgme.2007.04.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Accepted: 04/27/2007] [Indexed: 10/23/2022]
Abstract
Glycogen storage disease in the alpha-glucosidase knockout(6neo(-)/6neo(-)) (GAA KO) mouse, a model of Pompe disease, results in the pathologic accumulation of glycogen primarily within skeletal myocytes and cardiomyocytes. Intravenous administration of recombinant human alpha-glucosidase (rhGAA, Myozyme, aglucosidase alfa) can result in significant glycogen clearance from both cardiomyocytes and skeletal myocytes, however, the degree of clearance varies from one skeletal muscle type to another. We sought to determine what role muscle fiber type predominance played in this variability. To examine this question in the GAA KO mouse model we delivered intravenous doses of 100 mg/kg rhGAA on Day 1, and Day 14, and harvested a variety of fast and slow twitch muscles on Day 28. We measured glycogen clearance, muscle fiber type content and capillary density by light microscopy with computer morphometry. Recombinant human-GAA administration resulted in differential clearance of glycogen in the various muscles examined. Slow twitch-predominant muscles cleared glycogen significantly more efficiently than fast twitch-predominant muscles. There was a strong correlation between capillary density and glycogen clearance (r=0.55), suggesting that at the high doses used in this study the differential glycogen clearance observed between muscles is largely due to differential bioavailability of rhGAA regulated by blood flow.
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Affiliation(s)
- Michael L Hawes
- Department of Pathology, Genzyme Corporation, 1 Mountain Rd., P.O. Box 9322, Framingham, MA 01701-9322, USA
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Schoser BGH, Müller-Höcker J, Horvath R, Gempel K, Pongratz D, Lochmüller H, Müller-Felber W. Adult-onset glycogen storage disease type 2: clinico-pathological phenotype revisited. Neuropathol Appl Neurobiol 2007; 33:544-59. [PMID: 17573812 DOI: 10.1111/j.1365-2990.2007.00839.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The need for clinical awareness and diagnostic precision of glycogen storage disease type 2 (GSD2) has increased, as enzyme replacement therapy has become available. So far, only small series have reported the muscle pathology of late-onset GSD2. We reassessed 43 muscle biopsies of 38 GSD2 patients. In all patients the diagnosis of GSD2 has been established by biochemistry and/or mutational analysis of the GAA gene. Additionally to the expected morphological features, ultrastructural analysis revealed a high incidence of autophagic vacuoles, lipofuscin debris, structural Z-line disorganization and histological neurogenic-like pattern that were not thoroughly appreciated, previously. Comparing age at onset and morphology, excessive vacuolar and autophagic myopathy and mitochondrial disorganization of virtually all fibres is common in infants. At juvenile onset, a more moderate vacuolization without significant differences in overall morphology is notable. At late-onset, the spectrum of vacuolar myopathy is more divergent, ranging from almost normal to severe. Here pronounced secondary alterations are observed that include lipofuscin debris, autophagic vacuoles with residual lysosomal bodies and granular inclusions, structural mitochondrial and Z-line texture alterations. Moreover, there is a high incidence of subtle neurogenic-like alteration in all subtypes. Nineteen patients were genetically tested; in 15 patients the common leaky splicing mutation c.-45T>G (or IVS1-13T>G) in intron1 of the GAA gene was found on at least one allele, facilitating genetic screening. In our patients, GAA genotype appears not to be associated with secondary alterations such as autophagic vacuoles, structural alterations or neurogenic-like changes. These findings may have implications for our understanding of the pathogenesis of GSD2 and for assessing therapeutic success of enzyme replacement therapy.
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Affiliation(s)
- B G H Schoser
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University, Munich, Germany.
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88
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Taylor RW, Chinnery PF, Turnbull DM. Investigation of metabolic myopathies. HANDBOOK OF CLINICAL NEUROLOGY 2007; 86:193-204. [PMID: 18809001 DOI: 10.1016/s0072-9752(07)86009-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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89
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Okumiya T, Kroos MA, Vliet LV, Takeuchi H, Van der Ploeg AT, Reuser AJJ. Chemical chaperones improve transport and enhance stability of mutant alpha-glucosidases in glycogen storage disease type II. Mol Genet Metab 2007; 90:49-57. [PMID: 17095274 DOI: 10.1016/j.ymgme.2006.09.010] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Revised: 09/20/2006] [Accepted: 09/20/2006] [Indexed: 11/15/2022]
Abstract
Glycogen storage disease type II (GSDII; Pompe disease or acid maltase deficiency) is an autosomal recessive disorder caused by lysosomal acid alpha-glucosidase (AalphaGlu) deficiency and manifests predominantly as skeletal muscle weakness. Defects in post-translational modification and transport of mutant AalphaGlu species are frequently encountered and may potentially be corrected with chaperone-mediated therapy. In the present study, we have tested this hypothesis by using deoxynojirimycin and derivatives as chemical chaperones to correct the AalphaGlu deficiency in cultured fibroblasts from patients with GSDII. Four mutant phenotypes were chosen: Y455F/Y455F, P545L/P545L, 525del/R600C and D645E/R854X. In case of Y455F/Y455F and P545L/P545L, N-(n-butyl)deoxynojirimycin (NB-DNJ) restored the transport, maturation and activity of AalphaGlu in a dose dependent manner, while it had no effect on the reference enzyme beta-hexosaminidase. NB-DNJ promoted export from the endoplasmic reticulum (ER) to the lysosomes and stabilized the activity of mutant AalphaGlu species, Y455F and P545L, inside the lysosomes. In long-term culture, the AalphaGlu activity in the fibroblasts from the patients with mutant phenotypes, Y455F/Y455F and P545L/P545L, increased up to 14.0- and 7.9-fold, respectively, in the presence of 10mumol/L NB-DNJ. However, the effect of NB-DNJ on Y455F/Y455F subsided quickly after removal of the compound. We conclude that NB-DNJ acts in low concentration as chemical chaperone for certain mutant forms of AalphaGlu that are trapped in the ER, poorly transported or labile in the lysosomal environment. Chemical chaperone therapy could create new perspectives for therapeutic intervention in GSDII.
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Affiliation(s)
- Toshika Okumiya
- Department of Clinical Genetics, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
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90
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Park YE, Park KH, Lee CH, Kim CM, Kim DS. Two new missense mutations of GAA in late onset glycogen storage disease type II. J Neurol Sci 2006; 251:113-7. [PMID: 17092519 DOI: 10.1016/j.jns.2006.09.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 09/06/2006] [Accepted: 09/15/2006] [Indexed: 10/23/2022]
Abstract
Glycogen storage disease type II (GSD II) is an autosomal recessive disorder resulting from a deficiency of acid alpha-glucosidase (GAA, or acid maltase). In this study, we aimed to characterize phenotype and genotype in three patients with late onset GSD II in Korea. Clinically, all of our patients showed typical features of late onset GSD II with the reduced GAA enzyme activities. The respiratory difficulty preceding ambulatory failure seems to be one of the most remarkable clinical features characterizing late onset GSD II. By direct sequence analysis of PCR-amplified genomic DNA obtained from patients' skeletal muscle or peripheral leukocytes, we identified four missense mutations. Two of them (p.266Pro>Ser and p.439Met>Lys) were new missense mutations causing late onset GSD II, which had not been reported elsewhere before. One of them (p.439Met>Lys) was found in two alleles from each patient, suggesting it could be a recurrent mutation among Korean population.
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Affiliation(s)
- Young-Eun Park
- Department of Neurology, School of Medicine, Pusan National University, Busan, Republic of Korea
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91
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Kroos M, Manta P, Mavridou I, Muntoni F, Halley D, Van der Helm R, Zaifeiriou D, Van der Ploeg A, Reuser A, Michelakakis H. Seven cases of Pompe disease from Greece. J Inherit Metab Dis 2006; 29:556-63. [PMID: 16838077 DOI: 10.1007/s10545-006-0280-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Accepted: 04/25/2006] [Indexed: 10/24/2022]
Abstract
We present seven cases of Pompe disease (McKusick 232300; glycogen storage disease type II; acid maltase deficiency) from Greece. The onset of symptoms varied from early childhood to late adulthood, and the patients had quite variable duration of disease. All but one of them had muscle weakness and all had mildly to highly elevated serum creatine kinase. The diagnosis in all cases was confirmed by the finding of acid alpha-glucosidase (EC 3.2.1.3/20) deficiency in cultured skin fibroblasts. Thirteen mutant alleles were identified and nine different pathogenic mutations were encountered. Four were new: c.2071_2072insAGCCG leads to frameshift and total loss of function; c.1856G > A (p.Ser619Asn) leads to 90-95% loss of function; and the splice-site mutations c.1552-3C > G and c.2331+4A > G reduce the number of correct splicing events by more than 90%. The splice-site mutation c.-32-13T > G (IVS1-13T > G) was encountered four times and seems equally common among Greek and other caucasians. The other mutations: c.925G > A (p.Gly309Arg), c.[307T > G; 271G > A] (p.Cys103Gly; Asp91Asn), c.271del and c.1655T > C (p.Leu552Pro) have been reported earlier. Our study highlights the heterogeneity of Pompe disease in Greece and provides tools for diagnosis and carrier detection.
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Affiliation(s)
- M Kroos
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
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92
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Kakavanos R, Hopwood JJ, Lang D, Meikle PJ, Brooks DA. Stabilising normal and mis-sense variant alpha-glucosidase. FEBS Lett 2006; 580:4365-70. [PMID: 16846599 DOI: 10.1016/j.febslet.2006.06.096] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 06/07/2006] [Accepted: 06/29/2006] [Indexed: 11/26/2022]
Abstract
alpha-Glucosidase (EC 3.2.1.3) is a lysosomal enzyme that hydrolyses alpha-1,4- and alpha-1,6-linkages of glycogen to produce free glucose. A deficiency in alpha-glucosidase activity results in glycogen storage disorder type II (GSD II), also called Pompe disease. Here, d-glucose was shown to be a competitive inhibitor of alpha-glucosidase and when added to culture medium at 6.0 g/L increased the production of this protein by CHO-K1 expression cells and stabilised the enzyme activity. D-Glucose also prevented alpha-glucosidase aggregation/precipitation and increased protein yield in a modified purification scheme. In fibroblast cells, from adult-onset GSD II patients, D-glucose increased the residual level of alpha-glucosidase activity, suggesting that a structural analogue of d-glucose may be used for enzyme enhancement therapy.
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Affiliation(s)
- Revecca Kakavanos
- Department of Genetic Medicine, Lysosomal Diseases Research Unit, Children Youth and Women's Health Service, North Adelaide, SA 5006, Australia
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93
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Kishnani PS, Steiner RD, Bali D, Berger K, Byrne BJ, Case LE, Case L, Crowley JF, Downs S, Howell RR, Kravitz RM, Mackey J, Marsden D, Martins AM, Millington DS, Nicolino M, O'Grady G, Patterson MC, Rapoport DM, Slonim A, Spencer CT, Tifft CJ, Watson MS. Pompe disease diagnosis and management guideline. Genet Med 2006; 8:267-88. [PMID: 16702877 PMCID: PMC3110959 DOI: 10.1097/01.gim.0000218152.87434.f3] [Citation(s) in RCA: 355] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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94
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Dou W, Peng C, Zheng J, Gu X, Fu L, Martiniuk F, Sheng HZ. A novel missense mutation in the acid alpha-glucosidase gene causing the classic infantile form of Pompe disease. Clin Chim Acta 2006; 374:145-6. [PMID: 16782080 DOI: 10.1016/j.cca.2006.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Revised: 04/06/2006] [Accepted: 04/06/2006] [Indexed: 11/19/2022]
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95
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Ernst HA, Lo Leggio L, Willemoës M, Leonard G, Blum P, Larsen S. Structure of the Sulfolobus solfataricus alpha-glucosidase: implications for domain conservation and substrate recognition in GH31. J Mol Biol 2006; 358:1106-24. [PMID: 16580018 DOI: 10.1016/j.jmb.2006.02.056] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 02/21/2006] [Accepted: 02/22/2006] [Indexed: 11/26/2022]
Abstract
The crystal structure of alpha-glucosidase MalA from Sulfolobus solfataricus has been determined at 2.5Angstrom resolution. It provides a structural model for enzymes representing the major specificity in glycoside hydrolase family 31 (GH31), including alpha-glucosidases from higher organisms, involved in glycogen degradation and glycoprotein processing. The structure of MalA shows clear differences from the only other structure known from GH31, alpha-xylosidase YicI. MalA and YicI share only 23% sequence identity. Although the two enzymes display a similar domain structure and both form hexamers, their structures differ significantly in quaternary organization: MalA is a dimer of trimers, YicI a trimer of dimers. MalA and YicI also differ in their substrate specificities, as shown by kinetic measurements on model chromogenic substrates. In addition, MalA has a clear preference for maltose (Glc-alpha1,4-Glc), whereas YicI prefers isoprimeverose (Xyl-alpha1,6-Glc). The structural origin of this difference occurs in the -1 subsite where MalA residues Asp251 and Trp284 could interact with OH6 of the substrate. The structure of MalA in complex with beta-octyl-glucopyranoside has been determined. It reveals Arg400, Asp87, Trp284, Met321 and Phe327 as invariant residues forming the +1 subsite in the GH31 alpha-glucosidases. Structural comparisons with other GH families suggest that the GH31 enzymes belong to clan GH-D.
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Affiliation(s)
- Heidi A Ernst
- Biophysical Chemistry Group, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
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96
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Hesselink RP, Schaart G, Wagenmakers AJM, Drost MR, van der Vusse GJ. Age-related morphological changes in skeletal muscle cells of acid α-glucosidase knockout mice. Muscle Nerve 2006; 33:505-13. [PMID: 16372321 DOI: 10.1002/mus.20482] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Glycogen storage disease type II (GSDII), caused by a genetic defect in acid alpha-glucosidase (AGLU), leads to a decline in muscle contractility caused by both muscle wasting and a decrease in muscle quality, i.e., force generated per unit muscle mass. A previous study has shown that loss of muscle mass can only explain one-third of the decrease in contractile performance. Here we report on changes in the intramyocellular structural organization in a mouse knockout model (AGLU(-/-) mice) as a possible cause for the decline in muscle quality. Swollen, glycogen-filled lysosomes and centrally localized cores with cellular debris partially contribute to the decline in muscle quality. Altered localization and deposition of cytoskeletal proteins desmin and titin may reflect adaptive mechanisms at the age of 13 months, but a decline in quality at 20 months of age. The early deposition of lipofuscin in AGLU-deficient myocytes (13 months) is most likely a reflection of enhanced oxidative stress, which may also affect muscle quality. These collective findings, on the one hand, may explain the decrease in tissue quality and, on the other, may represent markers for efficacy of therapeutic interventions to restore muscle function in patients suffering from GSDII.
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Affiliation(s)
- Reinout P Hesselink
- Department of Movement Sciences, Cardiovascular Research Institute Maastricht, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
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97
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Montalvo ALE, Bembi B, Donnarumma M, Filocamo M, Parenti G, Rossi M, Merlini L, Buratti E, De Filippi P, Dardis A, Stroppiano M, Ciana G, Pittis MG. Mutation profile of theGAA gene in 40 Italian patients with late onset glycogen storage disease type II. Hum Mutat 2006; 27:999-1006. [PMID: 16917947 DOI: 10.1002/humu.20374] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Glycogen storage disease type II (GSDII) is a recessively inherited disorder due to the deficiency of acid alpha-glucosidase (GAA) that results in impaired glycogen degradation and its accumulation in the lysosomes. We report here the complete molecular analysis of the GAA gene performed on 40 Italian patients with late onset GSDII. Twelve novel alleles have been identified: missense mutations were functionally characterized by enzyme activity and protein processing in a human GAA-deficient cell line while splicing mutations were studied by RT-PCR and in silico analysis. A complex allele was also identified carrying three different alterations in cis. The c.-32-13T > G was the most frequent mutation, present as compound heterozygote in 85% of the patients (allele frequency 42.3%), as described in other late onset GSDII Caucasian populations. Interestingly, the c.-32-13T > G was associated with the c.2237G > A (p.W746X) in nine of the 40 patients. Genotype-phenotype correlations are discussed with particular emphasis on the subgroup carrying the c.-32-13T > G/c.2237G > A genotype.
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Affiliation(s)
- A L E Montalvo
- Unità di Malattie Metaboliche, IRCCS Burlo Garofolo, Trieste, Italy
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98
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Umapathysivam K, Hopwood JJ, Meikle PJ. Correlation of acid α-glucosidase and glycogen content in skin fibroblasts with age of onset in Pompe disease. Clin Chim Acta 2005; 361:191-8. [PMID: 15993875 DOI: 10.1016/j.cccn.2005.05.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2005] [Revised: 05/22/2005] [Accepted: 05/22/2005] [Indexed: 01/27/2023]
Abstract
BACKGROUND Pompe disease is an autosomal recessive disorder of glycogen metabolism resulting from a deficiency of acid alpha-glucosidase. Pompe disease can present within a broad clinical spectrum, from the severe infantile to the attenuated adult onset phenotypes. Early diagnosis, in the form of newborn screening has been proposed. However, in the absence of clinical symptoms, prediction of disease severity and progression will be critical to provide appropriate management and treatment of affected individuals. METHODS We have used sensitive immune-assays to measure levels of acid alpha-glucosidase protein and activity in cultured skin fibroblasts and a new glycogen assay to specifically determine the lysosomal accumulation of glycogen in the same cells. These markers were assessed for their ability to predict age of onset. RESULTS Acid alpha-glucosidase activity and specific activity as well as lysosomal glycogen showed significant correlations with age of onset, with acid alpha-glucosidase activity having the highest Spearman correlation coefficient (0.887, p<0.001). Lysosomal glycogen accumulated only in cells from infantile and juvenile patients but not from adult-onset patients. However, cells from adult-onset patients had relatively low cytoplasmic glycogen compared to control individuals and other forms of the disease. CONCLUSION Acid-alpha-glucosidase activity and specific activity, and lysosomal glycogen content are useful predictors of age of onset in Pompe disease.
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Affiliation(s)
- Kandiah Umapathysivam
- Lysosomal Diseases Research Unit, Department of Genetic Medicine, Child, Youth and Women's Health Service, 72 King William Road, North Adelaide, South Australia 5006, Australia
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99
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Sharma MC, Schultze C, von Moers A, Stoltenburg-Didinger G, Shin YS, Podskarbi T, Isenhardt K, Tews DS, Goebel HH. Delayed or late-onset type II glycogenosis with globular inclusions. Acta Neuropathol 2005; 110:151-7. [PMID: 15986226 DOI: 10.1007/s00401-005-1026-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Revised: 03/22/2005] [Accepted: 03/22/2005] [Indexed: 11/28/2022]
Abstract
Three unrelated patients, one girl, one boy, and an adult female, aged 14, 11 and 41 years, respectively, at the time of biopsy, revealed lysosomal glycogen storage, autophagic vacuoles and peculiar globular inclusions of distinct ultrastructure, which were reducing but did not appear like true "reducing bodies" as described in the congenital myopathy "reducing body myopathy". All three patients had residual activity of acid alpha-glucosidase in their muscle biopsy samples. Leukocytes in the girl showed normal acid alpha-glucosidase activity, but in the boy activity was reduced. Molecular genetic analysis of the GAA gene revealed disease-causing mutations in each patient: H568L/R672W, IVS1-13T>G/G615F, and IVS1-13T>G/IVS1-13T>G. Although only one patient with such globular inclusions has been reported up to now, the three patients described here indicate that in the late-onset type of GSD II such inclusions may not be rare.
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Affiliation(s)
- Mehar C Sharma
- Department of Neuropathology, Johannes Gutenberg University, Langenbeckstrasse 1, 55131, Mainz, Germany
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100
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Bruno C, van Diggelen OP, Cassandrini D, Gimpelev M, Giuffrè B, Donati MA, Introvini P, Alegria A, Assereto S, Morandi L, Mora M, Tonoli E, Mascelli S, Traverso M, Pasquini E, Bado M, Vilarinho L, van Noort G, Mosca F, DiMauro S, Zara F, Minetti C. Clinical and genetic heterogeneity of branching enzyme deficiency (glycogenosis type IV). Neurology 2005; 63:1053-8. [PMID: 15452297 DOI: 10.1212/01.wnl.0000138429.11433.0d] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Glycogen storage disease type IV (GSD-IV) is a clinically heterogeneous autosomal recessive disorder due to glycogen branching enzyme (GBE) deficiency and resulting in the accumulation of an amylopectin-like polysaccharide. The typical presentation is liver disease of childhood, progressing to lethal cirrhosis. The neuromuscular form of GSD-IV varies in onset (perinatal, congenital, juvenile, or adult) and severity. OBJECTIVE To identify the molecular bases of different neuromuscular forms of GSD-IV and to establish possible genotype/phenotype correlations. METHODS Eight patients with GBE deficiency had different neuromuscular presentations: three had fetal akinesia deformation sequence (FADS), three had congenital myopathy, one had juvenile myopathy, and one had combined myopathic and hepatic features. In all patients, the promoter and the entire coding region of the GBE gene at the RNA and genomic level were sequenced. RESULTS Nine novel mutations were identified, including nonsense, missense, deletion, insertion, and splice-junction mutations. The three cases with FADS were homozygous, whereas all other cases were compound heterozygotes. CONCLUSIONS This study expands the spectrum of mutations in the GBE gene and confirms that the neuromuscular presentation of GSD-IV is clinically and genetically heterogeneous.
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Affiliation(s)
- C Bruno
- Neuromuscular Disease Unit, Department of Pediatrics, University of Genova, Istituto Giannina Gaslini, Largo G. Gaslini 5, I-16147 Genova, Italy.
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