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Chkioua L, Grissa O, Leban N, Gribaa M, Boudabous H, Turkia HB, Ferchichi S, Tebib N, Laradi S. The mutational spectrum of hunter syndrome reveals correlation between biochemical and clinical profiles in Tunisian patients. BMC MEDICAL GENETICS 2020; 21:111. [PMID: 32448126 PMCID: PMC7247178 DOI: 10.1186/s12881-020-01051-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 05/14/2020] [Indexed: 11/10/2022]
Abstract
Background Mucopolysaccharidosis type II (MPS II) or Hunter syndrome is an X-linked recessive lysosomal storage disorder resulting from deficient activity of iduronate 2-sulfatase (IDS) and the progressive lysosomal accumulation of sulfated glycosaminoglycans (GAGs). Methods A diagnosis of MPS II or Hunter syndrome was performed based on the following approach after a clinical and paraclinical suspicion. Two biochemical and molecular tests were carried out separately and according to the availability of the biological material. Results All patients in this cohort presented the most common MPS II clinical features. Electrophoresis of GAGs on a cellulose acetate plate in the presence of a high concentration of heparane sulfate showed an abnormal dermatan sulfate band in the patients compared with that in a control case. Furthermore, leukocyte IDS activity ranged from 0.00 to 0.75 nmol/h/mg of leukocyte protein in patients. Five previously reported mutations were identified in this study patients: one splice site mutation, c.240 + 1G > A; two missense mutations, p.R88P and p.G94D; a large deletion of exon 1 to exon 7; and one nonsense mutation, p.Q396*. In addition, two novel alterations were identified in the MPS II patients: one frame shift mutation, p.D450Nfs*95 and one nonsense mutation, p.Q204*. Additionally, five known IDS polymorphisms were identified in the patients: c.419–16 delT, c.641C > T (p.T214M), c.438 C > T (p.T146T), c.709-87G > A, and c.1006 + 38 T > C. Conclusions The high level of urine GAGs and the deficiency of iduronate 2-sulfatase activity was associated with the phenotype expression of Hunter syndrome. Molecular testing was useful for the patients’ phenotypic classification and the detection of carriers.
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Affiliation(s)
- L Chkioua
- Research Laboratory of Human Genome and Multifactorial Diseases, Faculty of Pharmacy, University of Monastir, Street Avicenne, 5000, Monastir, Tunisie.
| | - O Grissa
- Research Laboratory of Human Genome and Multifactorial Diseases, Faculty of Pharmacy, University of Monastir, Street Avicenne, 5000, Monastir, Tunisie
| | - N Leban
- Research Laboratory of Human Genome and Multifactorial Diseases, Faculty of Pharmacy, University of Monastir, Street Avicenne, 5000, Monastir, Tunisie
| | - M Gribaa
- Department of Cytogenetic and Reproductive Biology Farhat HACHED Hospital, Sousse, Tunisia
| | - H Boudabous
- Laboratory of pediatrics, La Rabta Hospital Tunis, Tunis, Tunisia
| | - H Ben Turkia
- Laboratory of pediatrics, La Rabta Hospital Tunis, Tunis, Tunisia
| | - S Ferchichi
- Biochemistry Laboratory, Farhat HACHED Hospital Sousse, Sousse, Tunisia
| | - N Tebib
- Laboratory of pediatrics, La Rabta Hospital Tunis, Tunis, Tunisia
| | - S Laradi
- The Auvergne-Rhône-Alpes Regional Branch of the French National Blood System EFS/GIMAP-EA 3064, 42100, Saint Etienne, France
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2
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Zanetti A, D’Avanzo F, Rigon L, Rampazzo A, Concolino D, Barone R, Volpi N, Santoro L, Lualdi S, Bertola F, Scarpa M, Tomanin R. Molecular diagnosis of patients affected by mucopolysaccharidosis: a multicenter study. Eur J Pediatr 2019; 178:739-753. [PMID: 30809705 PMCID: PMC6459791 DOI: 10.1007/s00431-019-03341-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 02/05/2019] [Accepted: 02/06/2019] [Indexed: 11/25/2022]
Abstract
Mucopolysaccharidoses (MPS) are a subgroup of 11 monogenic lysosomal storage disorders due to the deficit of activity of the lysosomal hydrolases deputed to the degradation of mucopolysaccharides. Although individually rare, all together they account for at least 1:25,000 live births. In this study, we present the genetic analysis of a population of 71 MPS patients enrolled in a multicenter Italian study. We re-annotated all variants, according to the latest recommendations, and re-classified them as suggested by the American College of Medical Genetics and Genomics. Variant distribution per type was mainly represented by missense mutations. Overall, 10 patients had received no molecular diagnosis, although 6 of them had undergone either HSCT or ERT, based on clinical and enzymatic evaluations. Moreover, nine novel variants are reported.Conclusions: Our analysis underlines the need to complete the molecular diagnosis in patients previously diagnosed only on a biochemical basis, suggests a periodical re-annotation of the variants and solicits their deposition in public databases freely available to clinicians and researchers. We strongly recommend a molecular diagnosis based on the analysis of the "trio" instead of the sole proband. These recommendations will help to obtain a complete and correct diagnosis of mucopolysaccharidosis, rendering also possible genetic counseling. What is known • MPS are a group of 11 metabolic genetic disorders due to deficits of enzymes involved in the mucopolysaccharides degradation. • Molecular analysis is commonly performed to confirm enzymatic assays. What is new • Eighty-six percent of the 71 patients we collected received a molecular diagnosis; among them, 9 novel variants were reported. • We stress the importance of molecular diagnosis in biochemically diagnosed patients, encourage a periodical re-annotation of variants according to the recent nomenclature and their publication in open databases.
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Affiliation(s)
- Alessandra Zanetti
- Laboratorio di Diagnosi e Terapia delle Malattie Lisosomiali, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Francesca D’Avanzo
- Laboratorio di Diagnosi e Terapia delle Malattie Lisosomiali, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Laura Rigon
- Laboratorio di Diagnosi e Terapia delle Malattie Lisosomiali, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Angelica Rampazzo
- Laboratorio di Diagnosi e Terapia delle Malattie Lisosomiali, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
| | | | - Rita Barone
- Department of Clinical and Experimental Medicine, Child Neurology and Psychiatry, University of Catania, Catania, Italy
| | - Nicola Volpi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Lucia Santoro
- Department of Clinical Sciences, Division of Pediatrics, Polytechnic University of Marche, Ospedali Riuniti, Presidio Salesi, Ancona, Italy
| | - Susanna Lualdi
- Laboratorio di Genetica Medica e Biobanche, Istituto Giannina Gaslini, Genoa, Italy
| | - Francesca Bertola
- School of Medicine and Surgery, University of Milano Bicocca, Monza, Italy
| | - Maurizio Scarpa
- Laboratorio di Diagnosi e Terapia delle Malattie Lisosomiali, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Rosella Tomanin
- Laboratorio di Diagnosi e Terapia delle Malattie Lisosomiali, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
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3
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Dvorakova L, Vlaskova H, Sarajlija A, Ramadza DP, Poupetova H, Hruba E, Hlavata A, Bzduch V, Peskova K, Storkanova G, Kecman B, Djordjevic M, Baric I, Fumic K, Barisic I, Reboun M, Kulhanek J, Zeman J, Magner M. Genotype-phenotype correlation in 44 Czech, Slovak, Croatian and Serbian patients with mucopolysaccharidosis type II. Clin Genet 2017; 91:787-796. [PMID: 27883178 DOI: 10.1111/cge.12927] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/07/2016] [Accepted: 11/17/2016] [Indexed: 11/26/2022]
Abstract
Mucopolysaccharidosis type II (Hunter syndrome, MPS II, OMIM 309900) is an X-linked lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase (IDS). We analyzed clinical and laboratory data from 44 Slavic patients with this disease. In total, 21 Czech, 7 Slovak, 9 Croatian and 7 Serbian patients (43 M/1 F) were included in the study (median age 11.0 years, range 1.2-43 years). Birth prevalence ranged from 1:69,223 (Serbia) to 1:192,626 (Czech Rep.). In the majority of patients (71%), the disease manifested in infancy. Cognitive functions were normal in 10 patients. Four, six and 24 patients had mild, moderate, and severe developmental delay, respectively, typically subsequent to developmental regression (59%). Residual enzyme activity showed no predictive value, and estimation of glycosaminoglycans (GAGs) had only limited importance for prognosis. Mutation analysis performed in 36 families led to the identification of 12 novel mutations, eight of which were small deletions/insertions. Large deletions/rearrangements and all but one small deletion/insertion led to a severe phenotype. This genotype-phenotype correlation was also identified in six cases with recurrent missense mutations. Based on patient genotype, the severity of the disease may be predicted with high probability in approximately half of MPS II patients.
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Affiliation(s)
- L Dvorakova
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - H Vlaskova
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - A Sarajlija
- Department of Metabolism and Clinical Genetics, Mother and Child Health Care Institute of Serbia, Belgrade, Serbia.,School of Medicine, University of Belgrade, Belgrade, Serbia
| | - D P Ramadza
- Department of Pediatrics, University Hospital Center, Zagreb, Croatia
| | - H Poupetova
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - E Hruba
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - A Hlavata
- 2nd Department of Pediatrics, Comenius University Medical School in Bratislava University Children's Hospital, Bratislava, Slovakia
| | - V Bzduch
- 1st Department of Pediatrics, Comenius University Medical School in Bratislava University Children's Hospital, Bratislava, Slovakia
| | - K Peskova
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - G Storkanova
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - B Kecman
- Department of Metabolism and Clinical Genetics, Mother and Child Health Care Institute of Serbia, Belgrade, Serbia
| | - M Djordjevic
- Department of Metabolism and Clinical Genetics, Mother and Child Health Care Institute of Serbia, Belgrade, Serbia.,School of Medicine, University of Belgrade, Belgrade, Serbia
| | - I Baric
- Department of Pediatrics, University Hospital Center and University of Zagreb, School of Medicine, Zagreb, Croatia
| | - K Fumic
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb and School of Medicine, Zagreb, Croatia
| | - I Barisic
- Department of Paediatrics, Children's Hospital Zagreb, School of Medicine, Zagreb, Croatia
| | - M Reboun
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - J Kulhanek
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - J Zeman
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic.,Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - M Magner
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
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4
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Zanetti A, Tomanin R, Rampazzo A, Rigon C, Gasparotto N, Cassina M, Clementi M, Scarpa M. A Hunter Patient with a Severe Phenotype Reveals Two Large Deletions and Two Duplications Extending 1.2 Mb Distally to IDS Locus. JIMD Rep 2014; 17:13-21. [PMID: 25059704 PMCID: PMC4241202 DOI: 10.1007/8904_2014_317] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 04/16/2014] [Accepted: 04/22/2014] [Indexed: 03/24/2023] Open
Abstract
Mucopolysaccharidosis type II (Hunter syndrome, MPS II) is an X-linked lysosomal storage disorder caused by the deficit of iduronate 2-sulfatase (IDS), an enzyme involved in the glycosaminoglycans (GAGs) degradation. We here report the case of a 9-year-old boy who was diagnosed with an extremely severe form of MPS II at 10 months of age. Sequencing of the IDS gene revealed the deletion of exons 1-7, extending distally and removing the entire pseudogene IDSP1. The difficulty to define the boundaries of the deletion and the particular severity of the patient phenotype suggested to verify the presence of pathological copy number variations (CNVs) in the genome, by the array CGH (aCGH) technology. The examination revealed the presence of two deletions alternate with two duplications, overall affecting a region of about 1.2 Mb distally to IDS gene. This is the first complex rearrangement involving IDS and extending to a large region located distally to it described in a severe Hunter patient, as evidenced by the CNVs databases interrogated. The analysis of the genes involved in the rearrangement and of the disorders correlated with them did not help to clarify the phenotype observed in our patient, except for the deletion of the IDS gene, which explains per se the Hunter phenotype. However, this cannot exclude a potential "contiguous gene syndrome" as well as the future rising of additional pathological symptoms associated with the other extra genes involved in the identified rearrangement.
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Affiliation(s)
- Alessandra Zanetti
- />Laboratory of Diagnosis and Therapy of Lysosomal Disorders, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
| | - Rosella Tomanin
- />Laboratory of Diagnosis and Therapy of Lysosomal Disorders, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
| | - Angelica Rampazzo
- />Laboratory of Diagnosis and Therapy of Lysosomal Disorders, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
| | - Chiara Rigon
- />Clinical Genetics Unit, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
| | - Nicoletta Gasparotto
- />Laboratory of Diagnosis and Therapy of Lysosomal Disorders, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
| | - Matteo Cassina
- />Clinical Genetics Unit, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
| | - Maurizio Clementi
- />Clinical Genetics Unit, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
| | - Maurizio Scarpa
- />Laboratory of Diagnosis and Therapy of Lysosomal Disorders, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
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5
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Brusius-Facchin AC, Schwartz IVD, Zimmer C, Ribeiro MG, Acosta AX, Horovitz D, Monlleó IL, Fontes MIB, Fett-Conte A, Sobrinho RPO, Duarte AR, Boy R, Mabe P, Ascurra M, de Michelena M, Tylee KL, Besley GTN, Garreton MCV, Giugliani R, Leistner-Segal S. Mucopolysaccharidosis type II: identification of 30 novel mutations among Latin American patients. Mol Genet Metab 2014; 111:133-8. [PMID: 24125893 DOI: 10.1016/j.ymgme.2013.08.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 08/23/2013] [Indexed: 10/26/2022]
Abstract
In this study, 103 unrelated South-American patients with mucopolysaccharidosis type II (MPS II) were investigated aiming at the identification of iduronate-2-sulfatase (IDS) disease causing mutations and the possibility of some insights on the genotype-phenotype correlation The strategy used for genotyping involved the identification of the previously reported inversion/disruption of the IDS gene by PCR and screening for other mutations by PCR/SSCP. The exons with altered mobility on SSCP were sequenced, as well as all the exons of patients with no SSCP alteration. By using this strategy, we were able to find the pathogenic mutation in all patients. Alterations such as inversion/disruption and partial/total deletions of the IDS gene were found in 20/103 (19%) patients. Small insertions/deletions/indels (<22 bp) and point mutations were identified in 83/103 (88%) patients, including 30 novel mutations; except for a higher frequency of small duplications in relation to small deletions, the frequencies of major and minor alterations found in our sample are in accordance with those described in the literature.
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Affiliation(s)
| | - I V D Schwartz
- Post Graduation Program in Medical Sciences, UFRGS, Porto Alegre, RS, Brazil; Department of Genetics, UFRGS, Porto Alegre, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Brazil
| | - C Zimmer
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Brazil
| | - M G Ribeiro
- Clinical Genetics Service, IPPMG, UFRJ, Rio de Janeiro, Brazil
| | - A X Acosta
- Department of Pediatrics, UFBA, Salvador, Brazil
| | - D Horovitz
- Instituto Fernandes Figueira, FIOCRUZ, Rio de Janeiro, Brazil
| | - I L Monlleó
- Department of Pediatrics, UNCISAL, Maceió, Brazil
| | - M I B Fontes
- Department of Pediatrics, UNCISAL, Maceió, Brazil
| | - A Fett-Conte
- Department of Molecular Biology, FAMERP, São José do Rio Preto, Brazil
| | | | - A R Duarte
- Medical Genetics Service, IMIP, Recife, Brazil
| | - R Boy
- Mother and Child Department, UERJ, Rio de Janeiro, Brazil
| | - P Mabe
- Genetics and Metabolic Diseases Unit, INTA, University of Chile, Chile
| | - M Ascurra
- Department of Genetics, ILCS-UNA, Asunción, Paraguay
| | | | - K L Tylee
- Willink Biochemical Genetics Unit, Royal Manchester Children's Hospital, Manchester, UK
| | - G T N Besley
- Willink Biochemical Genetics Unit, Royal Manchester Children's Hospital, Manchester, UK
| | - M C V Garreton
- Unidad de Genética Clínica, Hospital Roberto del Río, Santiago, Chile
| | - R Giugliani
- Post Graduation Program in Medical Sciences, UFRGS, Porto Alegre, RS, Brazil; Department of Genetics, UFRGS, Porto Alegre, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Brazil
| | - S Leistner-Segal
- Post Graduation Program in Medical Sciences, UFRGS, Porto Alegre, RS, Brazil; Department of Genetics, UFRGS, Porto Alegre, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Brazil.
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6
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Dean CJ, Bockmann MR, Hopwood JJ, Brooks DA, Meikle PJ. Detection of mucopolysaccharidosis type II by measurement of iduronate-2-sulfatase in dried blood spots and plasma samples. Clin Chem 2006; 52:643-9. [PMID: 16497940 DOI: 10.1373/clinchem.2005.061838] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Mucopolysaccharidosis type II (MPS II) is a lysosomal storage disorder related to a deficiency in the enzyme iduronate-2-sulfatase (IDS). Clinical trials of enzyme replacement therapy are in progress, but effective treatment will require screening assays to enable early detection and diagnosis of MPS II. Our study evaluated the diagnostic accuracy of IDS protein and enzyme activity measurements in dried blood spots and plasma. METHODS We collected dried-blood-spot and plasma samples from unaffected control individuals and from MPS II patients. We measured IDS protein concentration with a 2-step time-delayed dissociation-enhanced lanthanide fluorescence immunoassay. To measure enzyme activity, we immobilized anti-IDS antibody on microtiter plates to capture the enzyme and measured its activity with the fluorogenic substrate 4-methylumbelliferyl sulfate. RESULTS Dried-blood-spot samples from MPS II patients showed an almost total absence of IDS activity (0-0.075 micromol x h(-1) x L(-1)) compared with control blood spots (0.5-4.7 micromol x h(-1) x L(-1)) and control plasma (0.17-8.1 micromol x h(-1) x L(-1)). A dried-blood-spot sample from only 1 of 12 MPS II patients had detectable concentrations of IDS protein (24.8 microg/L), but no IDS protein was detected in plasma from MPS II patients. Ranges for IDS protein in control samples were 25.8-153 microg/L for blood spots and 22.8-349.4 microg/L for plasma. CONCLUSION Measurement of the IDS protein concentration and enzyme activity (as measured by a simple fluorogenic assay with an immune capture technique) enables identification of the majority of MPS II patient samples from both dried blood spots and plasma samples.
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Affiliation(s)
- Caroline J Dean
- Lysosomal Diseases Research Unit, Department of Genetic Medicine, Children, Youth and Women's Health Service, North Adelaide, South Australia, Australia
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Villani GR, Daniele A, Balzano N, Di Natale P. Expression of five iduronate-2-sulfatase site-directed mutations. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1501:71-80. [PMID: 10838181 DOI: 10.1016/s0925-4439(00)00006-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Five point mutations (R88H, R88P, T118I, 959delT, R468Q) previously identified in the iduronate-2-sulfatase (IDS) gene of Italian Hunter patients were expressed in COS cells to evaluate their functional consequence on enzyme activity, processing and intracellular localization. The 88 arginine residue belongs to the CXPSR pentapeptide conserved in all human sulfatases, where cysteine modification to formylglycine is required for enzyme activity. Substitution of arginine with histidine residue resulted in 13.7% residual enzyme activity, with an apparent K(m) value (133 microM) lower than that found for the normal enzyme (327 microM), indicating a higher affinity for the substrate; substitution of arginine with proline resulted in total absence of residual activity, in agreement with the phenotypes observed in patients carrying R88H and R88P mutations. For the four missense mutations, pulse-chase labelling experiments showed an apparently normal maturation; however, subcellular fractionation demonstrated poor transport to lysosomes. Therefore, residues 88, 118 and 468 appear to be not essential for processing but important for IDS conformation.
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Affiliation(s)
- G R Villani
- Department of Biochemistry and Medical Biotechnologies, Medical School, University of Naples 'Federico II', Via S. Pansini 5, 80131, Naples, Italy
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Froissart R, Maire I, Millat G, Cudry S, Birot AM, Bonnet V, Bouton O, Bozon D. Identification of iduronate sulfatase gene alterations in 70 unrelated Hunter patients. Clin Genet 1998; 53:362-8. [PMID: 9660053 DOI: 10.1111/j.1399-0004.1998.tb02746.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
We studied 70 unrelated Hunter patients and found a gene alteration in every patient. The molecular heterogeneity was very important. Large gene rearrangements were identified in 14 patients. Forty-three different mutations were identified in the 56 other patients and 31 were not previously described. Deletions and insertions, splice site mutations were associated with a severe phenotype as nonsense mutations except Q531X. Only a few mutations were present in several patients making difficult genotype-phenotype correlations. Mutation identification allows accurate carrier detection improving prenatal diagnosis. The mother was not found to be a carrier in five cases among the 44 sporadic cases. Haplotype analysis demonstrated a higher frequency of mutations in male meiosis.
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Affiliation(s)
- R Froissart
- Biochimie Pédiatrique, Hôpital Debrousse, Lyon, France
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