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Zabihi R, Zamani M, Aminzadeh M, Chamanrou N, Kiani FZ, Seifi T, Zeighami J, Yadegari T, Sedaghat A, Saberi A, Hamid M, Shariati G, Galehdari H. Identification of new variants in patients with mucopolysaccharidosis in consanguineous Iranian families. Front Genet 2024; 15:1343094. [PMID: 38425718 PMCID: PMC10902845 DOI: 10.3389/fgene.2024.1343094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 01/25/2024] [Indexed: 03/02/2024] Open
Abstract
Introduction: Mucopolysaccharidoses are a group of lysosomal storage disorders that include seven types that are classified based on the enzymes that are disrupted. Malfunction of these enzymes leads to the accumulation of glycosaminoglycans (GAGs) in various tissues. Due to genetic and clinical heterogeneity, diagnosing and distinguishing the different types is challenging. Genetic methods such as whole exome sequencing (WES) and Sanger sequencing are accurate methods for detecting pathogenic variants in patients. Methods: Thirty-two cases of mucopolysaccharidosis, predominantly from families with consanguineous marriages, were genetically examined. Out of these, fourteen cases underwent targeted sequencing, while the rest underwent WES. The results of WES were analyzed and the pathogenicity of the variants was examined using bioinformatics tools. In addition, a segregation analysis within families was carried out. Results: In most cases, a pathogenic or likely pathogenic variant was detected. Sixteen previously reported variants and six new variants were detected in the known IDS (c.458G>C, c.701del, c.920T>G), GNS (c.1430A>T), GALNS (c.1218_1221dup), and SGSH (c.149T>C) genes. Furthermore, we discovered a c.259G>C substitution in the NAGLU gene for the first time in three homozygous patients. This substitution was previously reported as heterozygous. Except for the variants related to the IDS gene, which were hemizygous, all the other variants were homozygous. Discussion: It appears that the high rate of consanguineous marriages in the families being studied has had a significant impact on the occurrence of this disease. Overall, these findings could expand the spectrum of pathogenic variants in mucopolysaccharidoses. Genetic methods, especially WES, are very accurate and can be used alone or in conjunction with other diagnostic methods for a more precise and rapid diagnosis of mucopolysaccharidoses. Additionally, they could be beneficial for family screening and disease prevention.
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Affiliation(s)
- Rezvan Zabihi
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Mina Zamani
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
| | - Majid Aminzadeh
- Diabetes Research Center, Ahvaz Jundishapour University of Medical Sciences, Ahvaz, Iran
| | - Niloofar Chamanrou
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
- Department of Genetics, Faculty of Science, Shahrekord University, Shahrekord, Iran
| | - Fatemeh Zahra Kiani
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
| | - Tahere Seifi
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
| | - Jawaher Zeighami
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
| | - Tahere Yadegari
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
| | - Alireza Sedaghat
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
- Diabetes Research Center, Ahvaz Jundishapour University of Medical Sciences, Ahvaz, Iran
| | - Alihossein Saberi
- Department of Medical Genetics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
- Cellular and Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mohammad Hamid
- Department of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Gholamreza Shariati
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
- Department of Medical Genetics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Hamid Galehdari
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
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Zhong L, Gao X, Wang Y, Qiu W, Han L, Gu X, Zhang H. Clinical characteristics and genotypes of 201 patients with mucopolysaccharidosis type II in China: A retrospective, observational study. Clin Genet 2023; 103:655-662. [PMID: 36945845 DOI: 10.1111/cge.14329] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/09/2023] [Accepted: 03/12/2023] [Indexed: 03/23/2023]
Abstract
Mucopolysaccharidosis type II (MPS II) is an X-linked recessive lysosomal storage disease caused by a disease-associated variant in the IDS gene, which encodes iduronate 2-sulfatase (IDS). We aimed to characterize the clinical characteristics and genotypes of the largest cohort of Chinese patients with MPS II and so gain a deeper understanding of natural disease progression. Patients with confirmed MPS II and without treatment were included. The disease was classified as severe in patients with neurological impairment, and as attenuated in patients aged >6 years without neurological impairment. Of the 201 male patients, 78.1% had severe MPS II. Cognitive regression occurred before age 6 years in 94.3% of patients. Of 122 IDS variants identified, 37 were novel. Among the large gene alteration types identified, only the frequency of IDS-IDS2 recombination was significantly higher in severe versus attenuated MPS II (P = 0.032). Some identified point variants could inform the understanding of genotype-phenotype correlations. In conclusion, this study showed that classification of the disease as attenuated should only be made in patients aged >6 years. Our findings expand the understanding of the genotype-phenotype relationship, inform the diagnostic process, and provide an indication of the likely prognosis.
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Affiliation(s)
- Lin Zhong
- Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, People's Republic of China
| | - Xiaolan Gao
- Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, People's Republic of China
| | - Yu Wang
- Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, People's Republic of China
| | - Wenjuan Qiu
- Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, People's Republic of China
| | - Lianshu Han
- Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, People's Republic of China
| | - Xuefan Gu
- Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, People's Republic of China
| | - Huiwen Zhang
- Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, People's Republic of China
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Zhang Z, Ma M, Zhang W, Zhou Y, Yao F, Zhu L, Wei M, Qiu Z. Phenotypic and genetic characteristics of 130 patients with mucopolysaccharidosis type II: A single-center retrospective study in China. Front Genet 2023; 14:1103620. [PMID: 36713083 PMCID: PMC9880164 DOI: 10.3389/fgene.2023.1103620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023] Open
Abstract
Background: Mucopolysaccharidosis Type II (MPS II) is a rare, progressive and ultimately fatal X-linked lysosomal storage disorder caused by mutations in the iduronate-2-sulfatase (IDS) gene. This report conducted a retrospective analysis to investigate the clinical characteristics, genotypes and management strategies in a large cohort of Chinese patients with MPS II. Methods: In this study, we explored 130 Chinese patients with MPS II between September 2008 and April 2022. Clinical manifestations, auxiliary examination, IDS pathogenic gene variants and IDS enzyme activity, surgical history were analysed in the study. Results: A total of 130 patients were enrolled and the mean age at diagnosis was 5 years old. This study found the most common symptoms in our patients were claw-like hands, followed by coarse facial features, birthmarks (Mongolian spot), delayed development, inguinal or umbilical hernia. The most commonly cardiac manifestations were valve abnormalities, which were mitral/tricuspid valve regurgitation (71.9%) and aortic/pulmonary valve regurgitation (36.8%). We had found 43 different IDS pathogenic gene variants in 55 patients, included 16 novel variants. The variants were concentrated in exon 9 (20% = 11/55), exon 3 (20% = 11/55) and exon 8 (15% = 8/55). A total of 50 patients (38.5%) underwent surgical treatment, receiving a total of 63 surgeries. The average age of first surgery was 2.6 years, and the majority of surgery (85.7%, 54/63) was operated before 4 years old. The most common and earliest surgery was hernia repair. Three patients were died of respiratory failure. Conclusion: This study provided additional information on the clinical, cardiac ultrasound and surgical procedure in MPS II patients. Our study expanded the genotype spectrum of MPS II. Based on these data, characterization of MPS II patients group could be used to early diagnosis and treatment of the disease.
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Affiliation(s)
- Zhenjie Zhang
- Department of Pediatrics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Mingsheng Ma
- Department of Pediatrics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Weimin Zhang
- Department of Genetics Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yu Zhou
- Department of Pediatrics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Fengxia Yao
- Department of Genetics Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lisi Zhu
- Department of Genetics Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Min Wei
- Department of Pediatrics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhengqing Qiu
- Department of Pediatrics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China,*Correspondence: Zhengqing Qiu,
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Muenzer J, Burton BK, Harmatz P, Gutiérrez-Solana LG, Ruiz-Garcia M, Jones SA, Guffon N, Inbar-Feigenberg M, Bratkovic D, Hale M, Wu Y, Yee KS, Whiteman DAH, Alexanderian D. Intrathecal idursulfase-IT in patients with neuronopathic mucopolysaccharidosis II: Results from a phase 2/3 randomized study. Mol Genet Metab 2022; 137:127-139. [PMID: 36027721 PMCID: PMC10826424 DOI: 10.1016/j.ymgme.2022.07.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 07/29/2022] [Accepted: 07/29/2022] [Indexed: 11/30/2022]
Abstract
Two-thirds of patients with mucopolysaccharidosis II (MPS II; Hunter syndrome) have cognitive impairment. This phase 2/3, randomized, controlled, open-label, multicenter study (NCT02055118) investigated the effects of intrathecally administered idursulfase-IT on cognitive function in patients with MPS II. Children older than 3 years with MPS II and mild-to-moderate cognitive impairment (assessed by Differential Ability Scales-II [DAS-II], General Conceptual Ability [GCA] score) who had tolerated intravenous idursulfase for at least 4 months were randomly assigned (2:1) to monthly idursulfase-IT 10 mg (n = 34) via an intrathecal drug delivery device (IDDD; or by lumbar puncture) or no idursulfase-IT treatment (n = 15) for 52 weeks. All patients continued to receive weekly intravenous idursulfase 0.5 mg/kg as standard of care. Of 49 randomized patients, 47 completed the study (two patients receiving idursulfase-IT discontinued). The primary endpoint (change from baseline in DAS-II GCA score at week 52 in a linear mixed-effects model for repeated measures analysis) was not met: although there was a smaller decrease in DAS-II GCA scores with idursulfase-IT than with no idursulfase-IT at week 52, this was not significant (least-squares mean treatment difference [95% confidence interval], 3.0 [-7.3, 13.3]; p = 0.5669). Changes from baseline in Vineland Adaptive Behavioral Scales-II Adaptive Behavior Composite scores at week 52 (key secondary endpoint) were similar in the idursulfase-IT (n = 31) and no idursulfase-IT (n = 14) groups. There were trends towards a potential positive effect of idursulfase-IT across DAS-II composite, cluster, and subtest scores, notably in patients younger than 6 years at baseline. In a post hoc analysis, there was a significant (p = 0.0174), clinically meaningful difference in change from baseline in DAS-II GCA scores at week 52 with idursulfase-IT (n = 13) versus no idursulfase-IT (n = 6) among those younger than 6 years with missense iduronate-2-sulfatase gene variants. Overall, idursulfase-IT reduced cerebrospinal glycosaminoglycan levels from baseline by 72.0% at week 52. Idursulfase-IT was generally well tolerated. These data suggest potential benefits of idursulfase-IT in the treatment of cognitive impairment in some patients with neuronopathic MPS II. After many years of extensive review and regulatory discussions, the data were found to be insufficient to meet the evidentiary standard to support regulatory filings.
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Affiliation(s)
- Joseph Muenzer
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Barbara K Burton
- Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University, Chicago, IL, USA
| | - Paul Harmatz
- UCSF Benioff Children's Hospital Oakland, Oakland, CA, USA
| | | | | | - Simon A Jones
- St Mary's Hospital, Manchester University NHS Foundation Trust, University of Manchester, Manchester, UK
| | - Nathalie Guffon
- Reference Center for Inherited Metabolic Diseases, Hospices Civils de Lyon, Lyon, France
| | - Michal Inbar-Feigenberg
- University of Toronto, Toronto, ON, Canada; The Hospital for Sick Children, Toronto, ON, Canada
| | - Drago Bratkovic
- Women's and Children's Hospital, North Adelaide, SA, Australia
| | - Michael Hale
- Takeda Development Center Americas, Inc., Cambridge, MA, USA; Hale Scientific Statistics, LLC, Beaverton, OR, USA
| | - Yuna Wu
- Takeda Development Center Americas, Inc., Lexington, MA, USA
| | - Karen S Yee
- Takeda Development Center Americas, Inc., Cambridge, MA, USA
| | | | - David Alexanderian
- Takeda Development Center Americas, Inc., Lexington, MA, USA; Affinia Therapeutics, Inc., Waltham, MA, USA
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Muenzer J, Burton BK, Harmatz P, Gutiérrez-Solana LG, Ruiz-Garcia M, Jones SA, Guffon N, Inbar-Feigenberg M, Bratkovic D, Hale M, Wu Y, Yee KS, Whiteman DAH, Alexanderian D. Long-term open-label extension study of the safety and efficacy of intrathecal idursulfase-IT in patients with neuronopathic mucopolysaccharidosis II. Mol Genet Metab 2022; 137:92-103. [PMID: 35961250 PMCID: PMC10826456 DOI: 10.1016/j.ymgme.2022.07.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 07/29/2022] [Accepted: 07/29/2022] [Indexed: 11/23/2022]
Abstract
Enzyme replacement therapy with weekly infused intravenous (IV) idursulfase is effective in treating somatic symptoms of mucopolysaccharidosis II (MPS II; Hunter syndrome). A formulation of idursulfase for intrathecal administration (idursulfase-IT) is under investigation for the treatment of neuronopathic MPS II. Here, we report 36-month data from the open-label extension (NCT02412787) of a phase 2/3, randomized, controlled study (HGT-HIT-094; NCT02055118) that assessed the safety and efficacy of monthly idursulfase-IT 10 mg in addition to weekly IV idursulfase on cognitive function in children older than 3 years with MPS II and mild-to-moderate cognitive impairment. Participants were also enrolled in this extension from a linked non-randomized sub-study of children younger than 3 years at the start of idursulfase-IT therapy. The extension safety population comprised 56 patients who received idursulfase-IT 10 mg once a month (or age-adjusted dose for sub-study patients) plus IV idursulfase (0.5 mg/kg) once a week. Idursulfase-IT was generally well tolerated over the cumulative treatment period of up to 36 months. Overall, 25.0% of patients had at least one adverse event (AE) related to idursulfase-IT; most treatment-emergent AEs were mild in severity. Of serious AEs (reported by 76.8% patients), none were considered related to idursulfase-IT treatment. There were no deaths or discontinuations owing to AEs. Secondary efficacy analyses (in patients younger than 6 years at phase 2/3 study baseline; n = 40) indicated a trend for improved Differential Ability Scale-II (DAS-II) General Conceptual Ability (GCA) scores in the early idursulfase-IT versus delayed idursulfase-IT group (treatment difference over 36 months from phase 2/3 study baseline: least-squares mean, 6.8 [90% confidence interval: -2.1, 15.8; p = 0.2064]). Post hoc analyses of DAS-II GCA scores by genotype revealed a clinically meaningful treatment effect in patients younger than 6 years with missense variants of the iduronate-2-sulfatase gene (IDS) (least-squares mean [standard error] treatment difference over 36 months, 12.3 [7.24]). These long-term data further suggest the benefits of idursulfase-IT in the treatment of neurocognitive dysfunction in some patients with MPS II. After many years of extensive review and regulatory discussions, the data were found to be insufficient to meet the evidentiary standard to support regulatory filings.
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Affiliation(s)
- Joseph Muenzer
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Barbara K Burton
- Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University, Chicago, IL, USA
| | - Paul Harmatz
- UCSF Benioff Children's Hospital Oakland, Oakland, CA, USA
| | | | | | - Simon A Jones
- St Mary's Hospital, Manchester University NHS Foundation Trust, University of Manchester, Manchester, UK
| | - Nathalie Guffon
- Reference Center for Inherited Metabolic Diseases, Hospices Civils de Lyon, Lyon, France
| | - Michal Inbar-Feigenberg
- University of Toronto, Toronto, ON, Canada; The Hospital for Sick Children, Toronto, ON, Canada
| | - Drago Bratkovic
- Women's and Children's Hospital, North Adelaide, SA, Australia
| | - Michael Hale
- Takeda Development Center Americas, Inc., Cambridge, MA, USA; Hale Scientific Statistics, LLC, Beaverton, OR, USA
| | - Yuna Wu
- Takeda Development Center Americas, Inc., Lexington, MA, USA
| | - Karen S Yee
- Takeda Development Center Americas, Inc., Cambridge, MA, USA
| | | | - David Alexanderian
- Takeda Development Center Americas, Inc., Lexington, MA, USA; Affinia Therapeutics, Inc., Waltham, MA, USA
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Genotype-phenotype spectrum of 130 unrelated Indian families with Mucopolysaccharidosis type II. Eur J Med Genet 2022; 65:104447. [PMID: 35144014 DOI: 10.1016/j.ejmg.2022.104447] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 12/20/2021] [Accepted: 02/06/2022] [Indexed: 11/22/2022]
Abstract
MPS II is an X linked recessive lysosomal storage disorder with multi-system involvement and marked molecular heterogeneity. In this study, we explored the clinical and molecular spectrum of 144 Indian patients with MPS II from 130 unrelated families. Clinical information was collected on a predesigned clinical proforma. Sanger method was employed to sequence all the exons and exon/intron boundaries of the IDS gene. In cases where causative variation was not detected by Sanger sequencing, MLPA and RFLP were performed to identify large deletions/duplications and complex rearrangements. Cytogenetic microarray was done in one patient to see the breakpoints and extent of deletion. In one patient with no detectable likely pathogenic or pathogenic variation, whole-genome sequencing was also performed. Novel variants were systematically assessed by in silico prediction software and protein modelling. The pathogenicity of variants was established based on ACMG criteria. An attempt was also made to establish a genotype-phenotype correlation. Positive family history was present in 31% (41/130) of patients. Developmental delay and intellectual disability were the main reasons for referral. Macrocephaly, coarse facies and dysostosis were present in almost all patients. Hepatosplenomegaly, joint contractures and short stature were the characteristic features, seen in 87% (101/116), 67.8% (74/109) and 41.4% (41/99) patients respectively. Attenuated phenotype was seen in 32.6% (47/144) patients, while severe phenotype was seen in 63% (91/144) patients. The detection rate for likely pathogenic or pathogenic variants in our cohort is 95.5% (107/112) by Sanger sequencing, MLPA and RFLP. We also found two variants of unknown significance, one each by Sanger sequencing and WGS. Total of 71 variants were identified by Sanger sequencing and 29 of these variants were found to be novel. Amongst the novel variants, there was a considerable proportion (51%) of frameshift variants (15/29). Almost half of the causative variants were located in exon 3,8 and 9. A significant genotype-phenotype correlation was also noted for both known and novel variants. This information about the genotype spectrum and phenotype will be helpful for diagnostic and prognostic purposes.
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Zhao XY, Qiao GM, Liu F. Identification and structure characterization of novel IDS variants causing mucopolysaccharidosis type II: A retrospective analysis of 30 Chinese children. Clin Chim Acta 2021; 523:386-394. [PMID: 34670126 DOI: 10.1016/j.cca.2021.10.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Mucopolysaccharidosis type II (MPS II) or Hunter syndrome is a rare X-linked recessive genetic disease resulting from deficient activity of the iduronate-2-sulfatase(IDS) enzyme and the accumulation of glycosaminoglycans in almost all cells, tissues and organs, which makes viscera function impaired.This study retrospectively analyzed the clinical characteristics, leukocyte IDS activity and mutations in the IDS gene of 30 Chinese children with MPS II. METHODS Whole-exome sequencing (WES) was performed on samples of the 30 patients. RESULTS A total of 25 mutations were identified in the IDS genes including 16 previously reported and 9 novel mutations (6 frameshift: c.815-818dupAACG, c.1453dupA, c.1270-1271delGT, c.1484-1485insTA, c.854delA, c.12_13delCC;3missense: c.325 T > G, c.140 T > C, c.248 T > G).The computer simulations of the protein structure analysis of the novel missense mutations showed these amino acid replacements (W109G tryptophan replaced by the glycine, L47P leucine replaced by the proline, V83G valine replaced by glycine) near the active site of IDS protein sulfatase domain and would cause a severe impairment of protein structure and function. CONCLUSIONS Our study expands the spectrum of MPS II genotype, provides new insights into the molecular mechanisms of MPS II, and contributes to future studies of genotype-phenotypic associations to estimate prognosis and develop new treatment regimens.
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Affiliation(s)
- Xiao-Ying Zhao
- Department of Pediatrics, Hebei Medical University, Shijiazhuang 050000, Hebei, China
| | - Guang-Ming Qiao
- Department of Hematology, Children's Hospital of Integrated Traditional Chinese and Western Medicine, Shijiazhuang 050000, Hebei, China
| | - Fang Liu
- Department of Pediatrics, Hebei Medical University, Shijiazhuang 050000, Hebei, China; Department of Pediatrics, NICU, the 980th Hospital of the People's Liberation Army Joint Service Support Force, Shijiazhuang 050082, Hebei, China.
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A molecular genetics view on Mucopolysaccharidosis Type II. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2021; 788:108392. [PMID: 34893157 DOI: 10.1016/j.mrrev.2021.108392] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 06/03/2021] [Accepted: 08/05/2021] [Indexed: 02/07/2023]
Abstract
Mucopolysaccharidosis Type II (MPS II) is an X-linked recessive genetic disorder that primarily affects male patients. With an incidence of 1 in 100,000 male live births, the disease is one of the orphan diseases. MPS II symptoms are caused by mutations in the lysosomal iduronate-2-sulfatase (IDS) gene. The mutations cause a loss of enzymatic performance and result in the accumulation of glycosaminoglycans (GAGs), heparan sulfate and dermatan sulfate, which are no longer degradable. This inadvertent accumulation causes damage in multiple organs and leads either to a severe neurological course or to an attenuated course of the disease, although the exact relationship between mutation, extent of GAG accumulation and disease progression is not yet fully understood. This review is intended to present current diagnostic procedures and therapeutic interventions. In times when the genetic profile of patients plays an increasingly important role in the assessment of therapeutic success and future drug design, we chose to further elucidate the impact of genetic diversity within the IDS gene on disease phenotype and potential implications in current diagnosis, prognosis and therapy. We report recent advances in the structural biological elucidation of I2S enzyme that that promises to improve our future understanding of the molecular damage of the hundreds of IDS gene variants and will aid damage prediction of novel mutations in the future.
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Borges P, Pasqualim G, Giugliani R, Vairo F, Matte U. Estimated prevalence of mucopolysaccharidoses from population-based exomes and genomes. Orphanet J Rare Dis 2020; 15:324. [PMID: 33208168 PMCID: PMC7672855 DOI: 10.1186/s13023-020-01608-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/09/2020] [Indexed: 11/22/2022] Open
Abstract
Background In this study, the prevalence of different types of mucopolysaccharidoses (MPS) was estimated based on data from the exome aggregation consortium (ExAC) and the genome aggregation database (gnomAD). The population-based allele frequencies were used to identify potential disease-causing variants on each gene related to MPS I to IX (except MPS II).
Methods We evaluated the canonical transcripts and excluded homozygous, intronic, 3′, and 5′ UTR variants. Frameshift and in-frame insertions and deletions were evaluated using the SIFT Indel tool. Splice variants were evaluated using SpliceAI and Human Splice Finder 3.0 (HSF). Loss-of-function single nucleotide variants in coding regions were classified as potentially pathogenic, while synonymous variants outside the exon–intron boundaries were deemed non-pathogenic. Missense variants were evaluated by five in silico prediction tools, and only those predicted to be damaging by at least three different algorithms were considered disease-causing. Results The combined frequencies of selected variants (ranged from 127 in GNS to 259 in IDUA) were used to calculate prevalence based on Hardy–Weinberg's equilibrium. The maximum estimated prevalence ranged from 0.46 per 100,000 for MPSIIID to 7.1 per 100,000 for MPS I. Overall, the estimated prevalence of all types of MPS was higher than what has been published in the literature. This difference may be due to misdiagnoses and/or underdiagnoses, especially of the attenuated forms of MPS. However, overestimation of the number of disease-causing variants by in silico predictors cannot be ruled out. Even so, the disease prevalences are similar to those reported in diagnosis-based prevalence studies.
Conclusion We report on an approach to estimate the prevalence of different types of MPS based on publicly available population-based genomic data, which may help health systems to be better prepared to deal with these conditions and provide support to initiatives on diagnosis and management of MPS.
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Affiliation(s)
- Pâmella Borges
- Cell, Tissue and Gene Laboratory, Clinicas Hospital of Porto Alegre, Rio Grande do Sul, Brazil.,Experimental Research Centre, Bioinformatics Core, Clinicas Hospital of Porto Alegre, Rio Grande do Sul, Brazil.,Graduate Programme in Genetics and Molecular Biology, Federal University of Rio Grande Do Sul (UFRGS), Rio Grande do Sul, Brazil
| | - Gabriela Pasqualim
- Genetics Laboratory, Biological Sciences Institute, Federal University of Rio Grande (FURG), Rio Grande do Sul, Brazil
| | - Roberto Giugliani
- Graduate Programme in Genetics and Molecular Biology, Federal University of Rio Grande Do Sul (UFRGS), Rio Grande do Sul, Brazil.,Department of Genetics, UFRGS, Porto Alegre, Brazil.,Medical Genetics Service, HCPA, Porto Alegre, Brazil
| | - Filippo Vairo
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA. .,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA.
| | - Ursula Matte
- Cell, Tissue and Gene Laboratory, Clinicas Hospital of Porto Alegre, Rio Grande do Sul, Brazil.,Experimental Research Centre, Bioinformatics Core, Clinicas Hospital of Porto Alegre, Rio Grande do Sul, Brazil.,Graduate Programme in Genetics and Molecular Biology, Federal University of Rio Grande Do Sul (UFRGS), Rio Grande do Sul, Brazil.,Department of Genetics, UFRGS, Porto Alegre, Brazil
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A boy with mucopolysaccharidosis type II accompanied with a novel variation in heparan-N-sulfatase. Chin Med J (Engl) 2019; 132:2254-2256. [PMID: 31490262 PMCID: PMC6797137 DOI: 10.1097/cm9.0000000000000426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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Yuan X, Meng Y, Chen C, Liang S, Ma Y, Jiang W, Duan J, Wang C. Proteomic approaches in the discovery of potential urinary biomarkers of mucopolysaccharidosis type II. Clin Chim Acta 2019; 499:34-40. [PMID: 31469979 DOI: 10.1016/j.cca.2019.08.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 07/15/2019] [Accepted: 08/26/2019] [Indexed: 10/26/2022]
Abstract
Mucopolysaccharindosis type II (MPS II) is a rare lysosomal storage disorder caused by deficient or absent activity of the iduronate-2-sulfatase (IDS) enzyme, which leads to pathological accumulation of the glycosaminoglycans(GAGs). The absence of early diagnosis can result in irreversible developmental, neurological, and physiological damage. The lack of clear understanding of the etiology of physiological dysfunction in MPS II has been a major obstacle to the development of new treatment. Therefore, a reliable biomarker for early diagnosis and exploration of pathogenic mechanism are of great importance. Proteomics provides powerful tool for protein expression alterations and study of complicated pathological process. This study was performed to identify the differential protein profile in urine of MPS II patients using two-dimensional gel electrophoresis(2D-PAGE)combining with MALDI-TOF/TOF and a total of 15 differentially expressed proteins were identified. Content of alpha1-antitrypsin, Gm2 activator and lipocalin-type prostaglandin D synthase was measured by ELISA method. The value of urinary α1-AT/Cr in MPS II group was 0.79 ± 0.10 mg/mmol, significantly higher than 0.42 ± 0.05 mg/mmol in healthy control group; whereas the value of GM2A/Cr and L-PGDS/Cr in MPS II group was 1.30 ± 0.12 μg/mmol and 9.86 ± 1.16 ng/mmol respectively, which was significantly lower than 2.19 ± 0.19 μg/mmol and 13.98 ± 1.48 ng/mmol in healthy control group. The proteins can be considered as accessory diagnostic biomarkers for MPS II. This approach helped to discover early diagnostic markers and provided a better understanding of the pathogenic mechanism of MPS II.
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Affiliation(s)
- Xiaozhou Yuan
- Department of Clinical Laboratory, Chinese PLA General Hospital, Beijing 100853, China
| | - Yan Meng
- Department of pediatrics, Chinese PLA General Hospital, Beijing 100853, China
| | - Chen Chen
- Department of Clinical Laboratory, Chinese PLA General Hospital, Beijing 100853, China
| | - Shuang Liang
- Department of Clinical Laboratory, Chinese PLA General Hospital, Beijing 100853, China
| | - Yating Ma
- Department of Clinical Laboratory, Chinese PLA General Hospital, Beijing 100853, China
| | - Wencan Jiang
- Department of Clinical Laboratory, Chinese PLA General Hospital, Beijing 100853, China
| | - Jinyan Duan
- Department of Clinical Laboratory, Chinese PLA General Hospital, Beijing 100853, China.
| | - Chengbin Wang
- Department of Clinical Laboratory, Chinese PLA General Hospital, Beijing 100853, China.
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