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Sandahl TD, Laursen TL, Munk DE, Vilstrup H, Weiss KH, Ott P. The Prevalence of Wilson's Disease: An Update. Hepatology 2020; 71:722-732. [PMID: 31449670 DOI: 10.1002/hep.30911] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 08/21/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND AIMS In 1984, Scheinberg and Sternlieb estimated the prevalence of Wilson's disease to be 1:30,000 based on the limited available data. This suggested a large number of overlooked cases with potentially fatal consequences. The "Scheinberg-Sternlieb Estimate" is still widely used, although more recent clinical and genetic studies of higher quality are now available. In the present study, we included these data to update the prevalence estimate. APPROACH AND RESULTS A MEDLINE Ovid, Science Citation Index Expanded, and PubMed systematic search for all relevant studies on the prevalence of Wilson's disease was conducted. In total, 59 studies (50 clinical and 9 population-based genetic) were included in the final analysis. We identified 4 recent clinical studies based on nationwide databases of high quality, providing prevalence estimates from 1:29,000 to 1:40,000. Higher frequency populations do exist because of frequent first-cousin marriages and/or a higher mutation frequency. When calculating prevalence from the incidence related to number of births, estimates were 1:40,000-1:50,000. Clinical screening studies, including examination for Kayser-Fleischer rings or ceruloplasmin, did not improve these estimates because of insufficient sample size or selection biases. Population-based genetic studies in US and UK populations were not in disagreement with the clinically based estimates. At the same time, studies from France and Sardinia suggested that the genetic prevalence may be 3-4 times higher than the clinical disease prevalence. This raises the question whether the penetrance is indeed 100% as generally assumed. CONCLUSIONS The original prevalence estimate from 1984 of 1:30,000-1:50,000 still appears valid, at least for the United States, Europe, and Asia. In some population-based studies, the genetic prevalence was 3-4 times higher than clinically based estimates. The question of penetrance needs further evaluation.
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Affiliation(s)
| | - Tea Lund Laursen
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Ditte Emilie Munk
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Hendrik Vilstrup
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Karl Heinz Weiss
- Department of Internal Medicine IV, University Hospital Heidelberg, Heidelberg, Germany
| | - Peter Ott
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
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Liu WL, Li F, Liu L, Chen W, He ZX, Gu H, Ai R. A novel gross deletion and breakpoint junction sequence analysis of ATP7B in a Chinese family with Wilson disease using next‑generation sequencing and Sanger sequencing. Mol Med Rep 2019; 21:517-523. [PMID: 31746411 PMCID: PMC6896306 DOI: 10.3892/mmr.2019.10830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 10/15/2019] [Indexed: 11/15/2022] Open
Abstract
Wilson disease (WD) is a rare autosomal recessive genetic disorder that causes abnormal copper metabolism, resulting in pathological accumulation of copper in the liver, brain and other organs. Mutations in the ATPase copper transporter 7B (ATP7B) gene, which encodes a membrane P-type adenosine triphosphatase, have been identified as being responsible for WD. The present study analyzed clinical data and collected DNA samples from a pediatric patient with WD and her healthy parents. Mutation screening for ATP7B was performed using direct sequencing, multiplex ligation-dependent probe amplification(MLPA), next-generation sequencing (NGS) and Sanger sequencing of the breakpoint junction sequence. The patient (age, 2.7 years) presented with early-onset hepatic disease. The present study identified compound heterozygous mutations of ATP7B, including a heterozygous mutation (p.Arg1,041Trp) and a novel heterozygous gross deletion of a 57,771 bp fragment (chr13: 52490972-52548742) (GRCh37) from partial exon2- exon21 to external ATP7B sequence (15.833bp) in the patient. Analysis of the family members of the patient showed that the missense mutation and the gross deletion mutation were inherited from her mother and father, respectively. Microhomology and inverted repeat sequences, which may mediate the deletion mutation, were identified through sequence analysis on both sides of the breakpoints of this deletion. The present study provided additional information on the genotypic spectrum of the ATP7B gene, particularly with regard to early onset hepatic disease, as observed in the present patient with WD. The identification of the precise breakpoint junction sequence warrants further investigation of DNA break and recombination mechanisms. In detecting precise deletions, the NGS associated with Sanger sequencing of breakpoint junction sequence have been found to have more advantages than MLPA.
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Affiliation(s)
- Wei-Liang Liu
- Department of Pediatrics, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Fang Li
- Department of Ophthalmology, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Lu Liu
- Department of Ophthalmology, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Wei Chen
- Department of Ophthalmology, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Zhi-Xu He
- Department of Pediatrics, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Hao Gu
- Department of Ophthalmology, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Rong Ai
- Department of Pediatrics, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
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Chen YC, Yu H, Wang RM, Xie JJ, Ni W, Zhang Y, Dong Y, Wu ZY. Contribution of intragenic deletions to mutation spectrum in Chinese patients with Wilson's disease and possible mechanism underlying ATP7B gross deletions. Parkinsonism Relat Disord 2019; 62:128-133. [PMID: 30655162 DOI: 10.1016/j.parkreldis.2019.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 12/20/2018] [Accepted: 01/01/2019] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Wilson's disease (WD) is an autosomal recessive disorder of copper metabolism due to ATP7B pathogenic mutations. Disease manifestations can be prevented if early diagnosis and effective treatment are given. Direct sequencing is routinely used to confirm WD diagnosis, but cannot identify gross rearrangements. METHODS Sanger sequencing of ATP7B was performed in 142 newly recruited WD index patients. The clinical effects of identified variants were classified according to American College of Medical Genetics and Genomics (ACMG) standards and guidelines. Multiplex ligation-dependent probe amplification (MLPA) was performed in 168 WD cases with clinical WD unexplained by Sanger sequencing, selected from our total case series of 774 WD patients. After identifying gross rearrangements within ATP7B, the breakpoints were determined by long-range PCR and direct sequencing. RESULTS In the 142 WD patients, we identified 71 sequence alterations in ATP7B, of which 15 were novel; 14 of these were classified as 'pathogenic' or 'likely pathogenic', including 2 intronic variants affecting splice sites. In 6 of 168 WD patients, MLPA identified four heterozygous gross ATP7B deletions. One was a whole gene deletion, and three were intragenic deletions which were mapped to breakpoint locations, revealing non-homologous end joining. CONCLUSION Intragenic deletions are responsible for WD and non-homologous end joining could be the pathogenesis, therefore the detection of intragenic deletions should be included in comprehensive genetic testing for WD.
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Affiliation(s)
- Yu-Chao Chen
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China; Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Hao Yu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Rou-Min Wang
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Juan-Juan Xie
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Wang Ni
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Yue Zhang
- Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yi Dong
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China.
| | - Zhi-Ying Wu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China.
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Abstract
Wilson disease (WD) is an autosomal recessively-inherited disorder of copper metabolism and characterised by a pathological accumulation of copper. The ATP7B gene encodes for a transmembrane copper transporter essential for biliary copper excretion. Depending on time of diagnosis, severity of disease can vary widely. Almost all patients show evidence of progressive liver disease. Neurological impairments or psychiatric symptoms are common in WD patients not diagnosed during adolescence. WD is a treatable disorder, and early treatment can prevent the development of symptoms in patients diagnosed while still asymptomatic. This is why the early diagnosis of WD is crucial. The diagnosis is based on clinical symptoms, abnormal measures of copper metabolism and DNA analysis. Available treatment includes chelators and zinc salts which increase copper excretion and reduce copper uptake. In severe cases, liver transplantation is indicated and accomplishes a phenotypic correction of the hepatic gene defect. Recently, clinical development of the new copper modulating agent tetrathiomolybdate has started and direct genetic therapies are being tested in animal models. The following review focuses especially on biochemical markers and how they can be utilised in diagnosis and drug monitoring.
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Wang C, Zhou W, Huang Y, Yin H, Jin Y, Jia Z, Zhang A, Liu Z, Zheng B. Presumed missense and synonymous mutations in ATP7B gene cause exon skipping in Wilson disease. Liver Int 2018; 38:1504-1513. [PMID: 29637721 DOI: 10.1111/liv.13754] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 03/28/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND & AIMS Wilson disease is an inborn error of metabolism caused by abnormalities of the copper-transporting protein-encoding gene ATP7B. Recently, the phenomenon of exon skipping, in which exonic mutations result in abnormal splicing, has been associated with various diseases. The present study investigated the splicing defects of the ATP7B exonic variants identified in a cohort of 44 patients with Wilson disease. METHOD All patients were analysed for ATP7B gene by direct sequencing or multiplex ligation-dependent probe amplification analysis. To identify the potential pathogenicity of the candidate mutations that may induce exon skipping, both in vivo RT-PCR analysis using RNA from peripheral leukocytes and in vitro functional splicing by minigene construction were conducted. RESULTS The patterns of inheritance of the mutations in ATP7B identified in 44 patients exhibited homozygotes (7 patients), compound heterozygotes (32 patients) and heterozygotes (5 patients). In all patients, we detected 25 different ATP7B mutations, including 17 missenses, 1 frameshift, 3 nonsenses, 2 exonic deletions and 2 splicing alteration. In these mutations, 4 mutations have not been previously described in the literature or entered in human genome mutation database. Furthermore, we identified synonymous mutation c.4014T>A and missense mutation R919G caused exon skipping in the ATP7B mRNA transcript. CONCLUSION Our results suggest that aberrant exon skipping associated to putative splicing enhancer disruption and silencer creation is one previously unrecognized mechanism in Wilson disease. What is more, the multiplex ligation-dependent probe amplification assay for the detection of exon deletions may be valuable in individuals with clinical Wilson disease diagnosis where one or no mutation has been identified by sequencing.
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Affiliation(s)
- Chunli Wang
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Wei Zhou
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Yan Huang
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Hanjun Yin
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Yu Jin
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Zhanjun Jia
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Aihua Zhang
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Zhifeng Liu
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Bixia Zheng
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
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Shim JO, Yang HR, Moon JS, Chang JY, Ko JS, Park SS, Seo JK. Multiplex Ligation-dependent Probe Amplification Analysis Subsequent to Direct DNA Full Sequencing for Identifying ATP7B Mutations and Phenotype Correlations in Children with Wilson Disease. J Korean Med Sci 2018; 33:e177. [PMID: 29930488 PMCID: PMC6010744 DOI: 10.3346/jkms.2018.33.e177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 04/17/2018] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Mutations in ATP7B cause Wilson disease (WD). However, direct DNA full sequencing cannot detect all mutations in patients with WD. Multiplex ligation-dependent probe amplification (MLPA) analysis is reportedly useful in increasing the diagnostic yield in other genetic disorders with large deletions or insertions. The aim of this study was to evaluate whether the detection rate of ATP7B mutations can be increased by using MLPA. METHODS We enrolled 114 children with WD from 104 unrelated families based on biochemical tests and direct DNA full sequencing. The patients with one or zero mutant allele were investigated using MLPA. We analyzed phenotypic correlations. RESULTS Total allele frequency by full sequencing was 87.5%. Full sequencing revealed two mutant alleles in 80 of 104 unrelated children. One mutant allele was detected in 22 children, and no mutations were found in two children. Novel mutations including small deletions with frameshift mutations were identified by DNA sequencing. MLPA revealed no gross deletion or duplication in 24 children with one or zero mutant alleles. The number of detected mutations was not associated with hepatic manifestation, age of onset, Kayser-Fleischer ring, ceruloplasmin, and urinary Cu concentrations. CONCLUSION MLPA showed a limited role to increase the mutation detection rate in children who do not receive a definite genetic diagnosis of WD through DNA full sequencing. This finding suggests that large deletions or duplications might be extremely rare in WD. Further development is needed to improve the genetic diagnosis of WD.
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Affiliation(s)
- Jung Ok Shim
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
- Department of Pediatrics, Korea University College of Medicine, Seoul, Korea
| | - Hye Ran Yang
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Jin Soo Moon
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Ju Young Chang
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Jae Sung Ko
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Sung Sup Park
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Jeong Kee Seo
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
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Liu G, Ma D, Cheng J, Zhang J, Luo C, Sun Y, Hu P, Wang Y, Jiang T, Xu Z. Identification and characterization of a novel 43-bp deletion mutation of the ATP7B gene in a Chinese patient with Wilson's disease: a case report. BMC MEDICAL GENETICS 2018; 19:61. [PMID: 29649982 PMCID: PMC5898064 DOI: 10.1186/s12881-018-0567-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 03/21/2018] [Indexed: 01/15/2023]
Abstract
Background Wilson’s disease (WD) is an autosomal recessive disorder characterized by copper accumulation. ATP7B gene mutations lead to ATP7B protein dysfunction, which in turn causes Wilson’s disease. Case presentation We describe a male case of Wilson’s disease diagnosed at 10 years after routine biochemical test that showed low serum ceruloplasmin levels and Kayser–Fleischer rings in both corneas. Analysis of the ATP7B gene revealed compound heterozygous mutations in the proband, including the reported c.3517G > A mutation and a novel c.532_574del mutation. The c.532_574del mutation covered a 43-bp region in exon 2, and resulted in a frameshift mutation (p.Leu178PhefsX10). By base sequence analysis, two microhomologies (TCTCA) were observed on both deletion breakpoints in the ATP7B gene. Meanwhile, the presence of some sequence motifs associated with DNA breakage near the deletion region promoted DNA strand break. Conclusions By comparison, a replication-based mechanism named fork stalling and template switching/ microhomology-mediated break-induced replication (FoSTeS/MMBIR) was used to explain the formation of this novel deletion mutation. Electronic supplementary material The online version of this article (10.1186/s12881-018-0567-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gang Liu
- State key Laboratory of Reproductive Medicine, Department of Prenatal Diagnosis, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, No.123, Tianfeixiang, Mochou Road, Nanjing, 210004, Jiangsu Province, China
| | - Dingyuan Ma
- State key Laboratory of Reproductive Medicine, Department of Prenatal Diagnosis, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, No.123, Tianfeixiang, Mochou Road, Nanjing, 210004, Jiangsu Province, China
| | - Jian Cheng
- State key Laboratory of Reproductive Medicine, Department of Prenatal Diagnosis, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, No.123, Tianfeixiang, Mochou Road, Nanjing, 210004, Jiangsu Province, China
| | - Jingjing Zhang
- State key Laboratory of Reproductive Medicine, Department of Prenatal Diagnosis, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, No.123, Tianfeixiang, Mochou Road, Nanjing, 210004, Jiangsu Province, China
| | - Chunyu Luo
- State key Laboratory of Reproductive Medicine, Department of Prenatal Diagnosis, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, No.123, Tianfeixiang, Mochou Road, Nanjing, 210004, Jiangsu Province, China
| | - Yun Sun
- State key Laboratory of Reproductive Medicine, Department of Prenatal Diagnosis, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, No.123, Tianfeixiang, Mochou Road, Nanjing, 210004, Jiangsu Province, China
| | - Ping Hu
- State key Laboratory of Reproductive Medicine, Department of Prenatal Diagnosis, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, No.123, Tianfeixiang, Mochou Road, Nanjing, 210004, Jiangsu Province, China
| | - Yuguo Wang
- State key Laboratory of Reproductive Medicine, Department of Prenatal Diagnosis, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, No.123, Tianfeixiang, Mochou Road, Nanjing, 210004, Jiangsu Province, China
| | - Tao Jiang
- State key Laboratory of Reproductive Medicine, Department of Prenatal Diagnosis, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, No.123, Tianfeixiang, Mochou Road, Nanjing, 210004, Jiangsu Province, China.
| | - Zhengfeng Xu
- State key Laboratory of Reproductive Medicine, Department of Prenatal Diagnosis, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, No.123, Tianfeixiang, Mochou Road, Nanjing, 210004, Jiangsu Province, China.
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Intragenic Deletions in ATP7B as an Unusual Molecular Genetics Mechanism of Wilson's Disease Pathogenesis. PLoS One 2016; 11:e0168372. [PMID: 27992490 PMCID: PMC5167361 DOI: 10.1371/journal.pone.0168372] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 11/29/2016] [Indexed: 01/17/2023] Open
Abstract
Wilson’s disease (WD) is an autosomal recessive disorder caused by mutations in the ATP7B resulting in copper overload in the liver and brain. Direct sequencing is routinely used to confirm WD diagnosis; however, partial and whole gene deletions in the heterozygous state cannot be detected by exon amplification since the normal allele will mask its presence. The aim of the present work was to search for unusual mutational events in the unexplained WD cases and to provide insight into the mechanisms. Out of 1420 clinically and biochemically confirmed WD samples received between 2000 and 2014 for routine mutation analysis, we were unable to detect mutant alleles in 142 samples, after extensive sequencing analysis. We used selective amplification and MLPA to identify the partial gene deletions and identified three different partial gene deletions in seven different families. All three deletions were fully characterized at the DNA sequence level. We report the first hemizygous case with WD due to intragenic deletion in the ATP7B (c.3134_3556+689del). This novel deletion resulted from an excision event mediated by consensus sequences in an AluSq2 repeat element and could be traced to micro homologous end joining (MMEJ). Finally, we determined the prevalence of the three deletions in DNA samples from a multinational group of WD patients. Our results emphasize the need for searching mutant alleles beyond routine methods and highlight that large ATP7B deletions are rare, but account for a detectable proportion in some WD patients. Screening for gene aberrations will further improve mutation detection in patients with unidentified ATP7B mutations presenting with clinical manifestations of WD.
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Dong Y, Ni W, Chen WJ, Wan B, Zhao GX, Shi ZQ, Zhang Y, Wang N, Yu L, Xu JF, Wu ZY. Spectrum and Classification of ATP7B Variants in a Large Cohort of Chinese Patients with Wilson's Disease Guides Genetic Diagnosis. Am J Cancer Res 2016; 6:638-49. [PMID: 27022412 PMCID: PMC4805659 DOI: 10.7150/thno.14596] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 01/27/2016] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Wilson's disease (WD) is an autosomal recessive disorder of copper metabolism caused by ATP7B pathogenic mutations. The symptoms of WD can be effectively prevented if the affected individuals are identified and intervened early. However, clinical utility of this molecular analysis is challenging due to hundreds of variants with various clinical effects in the gene. Here, we aim to describe the spectrum of ATP7B variants and assess their clinical effects in the Han Chinese population. METHODS The ATP7B gene was directly sequenced in 632 unrelated WD patients and 503 unrelated healthy individuals. The effects of identified variants were classified according to the American College of Medical Genetics and Genomics (ACMG) standards and guidelines. Different frequency of variants observed in both cases and controls were tested using Chi-square or Fisher's exact tests. RESULTS We detected 161 non-synonymous variants in these 632 WD patients, 58 of which were novel. Among these variants, 78, 64, 8, 4, and 7 were classified as 'pathogenic variants', 'likely pathogenic variants', 'variants with uncertain significance', 'likely benign variants', and 'benign variants', respectively. Ninety percent (569/632) of these WD patients can be genetically diagnosed with two or more 'pathogenic' or 'likely pathogenic' variants. The 14 most common disease-causing variants were found at least once in 94% (537/569) of genetically diagnosed patients. CONCLUSIONS These data expand the spectrum of ATP7B variants and facilitate effective screening for ATP7B variants for early diagnosis of WD and development of individualized treatment regimens.
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Targeted next-generation sequencing of the ATP7B gene for molecular diagnosis of Wilson disease. Clin Biochem 2015; 49:166-71. [PMID: 26483271 DOI: 10.1016/j.clinbiochem.2015.10.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 09/09/2015] [Accepted: 10/14/2015] [Indexed: 02/08/2023]
Abstract
OBJECTIVES In recent years, next-generation sequencing (NGS) technologies, which enable high throughput sample processing at relatively lower costs, are adopted in both research and clinical settings. A multiplex PCR-based NGS assay to identify mutations in the ATP7B gene for routine molecular diagnosis of Wilson disease was evaluated in comparison with the gold standard direct Sanger sequencing. DESIGN AND METHODS Five multiplex PCRs to amplify the partial promoter, 5' untranslated and the entire coding regions of the ATP7B gene were designed. Indexed paired-end libraries were generated from the pooled amplicons using Nextera XT DNA Sample Preparation Kit and subjected to NGS on the MiSeq platform. DNA from the peripheral blood of 12 patients with Wilson disease, 2 B-lymphocyte cell lines and 3 external quality assurance samples were sequenced by the MiSeq and Sanger sequencing. RESULTS Complete coverage was achieved across the targeted bases without any drop-out sequences. The observed read depth in a single run with 20 samples was >100X. Comparison of the NGS results against Sanger sequencing data on a panel of clinical specimens, cell lines and European Molecular Genetics Quality Networks (EMQN) quality assurance samples showed 100% concordance in identifying pathogenic mutations. CONCLUSION With the capability of generating relatively higher throughput in a short time period, the NGS assay is a viable alternative to Sanger sequencing for detecting ATP7B mutations causally linked to Wilson disease in the clinical diagnostic laboratory.
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Mameli E, Lepori MB, Chiappe F, Ranucci G, Di Dato F, Iorio R, Loudianos G. Wilson's disease caused by alternative splicing and Alu exonization due to a homozygous 3039-bp deletion spanning from intron 1 to exon 2 of the ATP7B gene. Gene 2015; 569:276-9. [PMID: 26031236 DOI: 10.1016/j.gene.2015.05.067] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 05/26/2015] [Accepted: 05/27/2015] [Indexed: 11/18/2022]
Abstract
We describe a case of Wilson's disease (WD) diagnosed at 5 years after routine biochemical test showed increased aminotransferases. Mutation analysis of the ATP7B gene revealed a 3039-bp deletion in the homozygous state spanning from the terminal part of intron 1 to nt position 368 of exon 2. This deletion results in the activation of 3 cryptic splice sites: an AG acceptor splice site in nt positions 578-579 producing a different breakpoint and removing the first 577 nts of exon 2, an acceptor and a donor splice site in nt positions 20363-4 and 20456-7, respectively, in intron 1, resulting in the activation of a 94-bp cryptic Alu exon being incorporated into the mature transcript. The resulting alternative transcript contains a TAG stop codon in the first amino acid position of the cryptic exon, likely producing a truncated, non-functional protein. This study shows that intron exonization can also occur in humans through naturally occurring gross deletions. The results suggest that the combination of DNA and RNA analyses can be used for molecular characterization of gross ATP7B deletions, thus improving genetic counseling and diagnosis of WD. Moreover these studies help to better establish new molecular mechanisms producing Wilson's disease.
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Affiliation(s)
- Eva Mameli
- Dipartimento di Sanita' Pubblica, Medicina Clinica e Molecolare, Universita' degli Studi di Cagliari, Italy
| | - Maria Barbara Lepori
- Dipartimento di Sanita' Pubblica, Medicina Clinica e Molecolare, Universita' degli Studi di Cagliari, Italy
| | - Francesca Chiappe
- Dipartimento di Sanita' Pubblica, Medicina Clinica e Molecolare, Universita' degli Studi di Cagliari, Italy
| | - Giusy Ranucci
- Department of Translational Medical Science, Section of Pediatrics, University Federico II, Naples, Italy
| | - Fabiola Di Dato
- Department of Translational Medical Science, Section of Pediatrics, University Federico II, Naples, Italy
| | - Raffaele Iorio
- Department of Translational Medical Science, Section of Pediatrics, University Federico II, Naples, Italy
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Dad S, Rendtorff ND, Kann E, Albrechtsen A, Mehrjouy MM, Bak M, Tommerup N, Tranebjærg L, Rosenberg T, Jensen H, Møller LB. Partial USH2A deletions contribute to Usher syndrome in Denmark. Eur J Hum Genet 2015; 23:1646-51. [PMID: 25804404 DOI: 10.1038/ejhg.2015.54] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 02/16/2015] [Accepted: 02/20/2015] [Indexed: 12/18/2022] Open
Abstract
Usher syndrome is an autosomal recessive disorder characterized by congenital hearing impairment, progressive visual loss owing to retinitis pigmentosa and in some cases vestibular dysfunction. Usher syndrome is divided into three subtypes, USH1, USH2 and USH3. Twelve loci and eleven genes have so far been identified. Duplications and deletions in PCDH15 and USH2A that lead to USH1 and USH2, respectively, have previously been identified in patients from United Kingdom, Spain and Italy. In this study, we investigate the proportion of exon deletions and duplications in PCDH15 and USH2A in 20 USH1 and 30 USH2 patients from Denmark using multiplex ligation-dependent probe amplification (MLPA). Two heterozygous deletions were identified in USH2A, but no deletions or duplications were identified in PCDH15. Next-generation mate-pair sequencing was used to identify the exact breakpoints of the two deletions identified in USH2A. Our results suggest that USH2 is caused by USH2A exon deletions in a small fraction of the patients, whereas deletions or duplications in PCDH15 might be rare in Danish Usher patients.
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Affiliation(s)
- Shzeena Dad
- Clinical Genetics Clinic, The Kennedy Center, Rigshospitalet, University of Copenhagen, Glostrup, Denmark
| | - Nanna D Rendtorff
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.,Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Bispebjerg Hospital/Rigshospitalet, Copenhagen, Denmark
| | - Erik Kann
- Clinical Genetics Clinic, The Kennedy Center, Rigshospitalet, University of Copenhagen, Glostrup, Denmark
| | - Anders Albrechtsen
- Department of Biology, Computational and RNA Biology, University of Copenhagen, Copenhagen, Denmark
| | - Mana M Mehrjouy
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Mads Bak
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Niels Tommerup
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Lisbeth Tranebjærg
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.,Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Bispebjerg Hospital/Rigshospitalet, Copenhagen, Denmark
| | - Thomas Rosenberg
- Department of Ophthalmology, The National Eye Clinic, Copenhagen University Hospital, The Kennedy Center, Glostrup, Denmark
| | - Hanne Jensen
- Department of Ophthalmology, The National Eye Clinic, Copenhagen University Hospital, The Kennedy Center, Glostrup, Denmark
| | - Lisbeth B Møller
- Clinical Genetics Clinic, The Kennedy Center, Rigshospitalet, University of Copenhagen, Glostrup, Denmark
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13
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Wu F, Wang J, Pu C, Qiao L, Jiang C. Wilson's disease: a comprehensive review of the molecular mechanisms. Int J Mol Sci 2015; 16:6419-31. [PMID: 25803104 PMCID: PMC4394540 DOI: 10.3390/ijms16036419] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 03/03/2015] [Accepted: 03/03/2015] [Indexed: 02/06/2023] Open
Abstract
Wilson’s disease (WD), also known as hepatolenticular degeneration, is an autosomal recessive inherited disorder resulting from abnormal copper metabolism. Reduced copper excretion causes an excessive deposition of the copper in many organs such as the liver, central nervous system (CNS), cornea, kidney, joints, and cardiac muscle where the physiological functions of the affected organs are impaired. The underlying molecular mechanisms for WD have been extensively studied. It is now believed that a defect in P-type adenosine triphosphatase (ATP7B), the gene encoding the copper transporting P-type ATPase, is responsible for hepatic copper accumulation. Deposited copper in the liver produces toxic effects via modulating several molecular pathways. WD can be a lethal disease if left untreated. A better understanding of the molecular mechanisms causing the aberrant copper deposition and organ damage is the key to developing effective management approaches.
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Affiliation(s)
- Fei Wu
- Department of imaging, the Affiliated Zhongshan Hospital of Dalian University, 6 Jiefang Street, Zhongshan District, Dalian 116001, Liaoning, China.
| | - Jing Wang
- Department of Internal Medicine, the Second Hospital of Dalian Medical University, 467 Zhongshan Road, Shahekou District, Dalian 116023, Liaoning, China.
| | - Chunwen Pu
- Department of Biobank, the Sixth People's Hospital of Dalian, 269 Luganghuibai Road, Ganjingzi District, Dalian 116031, Liaoning, China.
| | - Liang Qiao
- Storr Liver Centre, Westmead Millennium Institute for Medical Research, Faculty of Medicine, the University of Sydney at Westmead Hospital, Westmead, NSW 2145, Australia.
| | - Chunmeng Jiang
- Department of Internal Medicine, the Second Hospital of Dalian Medical University, 467 Zhongshan Road, Shahekou District, Dalian 116023, Liaoning, China.
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14
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Abstract
The copper metabolism disorder Wilson's disease was first defined in 1912. Wilson's disease can present with hepatic and neurological deficits, including dystonia and parkinsonism. Early-onset presentations in infancy and late-onset manifestations in adults older than 70 years of age are now well recognised. Direct genetic testing for ATP7B mutations are increasingly available to confirm the clinical diagnosis of Wilson's disease, and results from biochemical and genetic prevalence studies suggest that Wilson's disease might be much more common than previously estimated. Early diagnosis of Wilson's disease is crucial to ensure that patients can be started on adequate treatment, but uncertainty remains about the best possible choice of medication. Furthermore, Wilson's disease needs to be differentiated from other conditions that also present clinically with hepatolenticular degeneration or share biochemical abnormalities with Wilson's disease, such as reduced serum ceruloplasmin concentrations. Disordered copper metabolism is also associated with other neurological conditions, including a subtype of axonal neuropathy due to ATP7A mutations and the late-onset neurodegenerative disorders Alzheimer's disease and Parkinson's disease.
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Affiliation(s)
- Oliver Bandmann
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK.
| | - Karl Heinz Weiss
- University Hospital Heidelberg, Department of Internal Medicine IV, Heidelberg, Germany
| | - Stephen G Kaler
- Section on Translational Neuroscience, Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
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15
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Liu Y, Zhou H, Guo H, Bai Y. Genetic and Clinical Analysis in a Cohort of Patients with Wilson's Disease in Southwestern China. Arch Med Res 2015; 46:164-9. [PMID: 25704634 DOI: 10.1016/j.arcmed.2015.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 02/03/2015] [Indexed: 01/06/2023]
Abstract
BACKGROUND AND AIMS Wilson's disease (WD), characterized by a disorder of copper metabolism, is an inherited autosomal recessive disease caused by mutations in the ATP7B gene. METHODS To explore genotype-phenotype correlations in Chinese WD patients and to evaluate the frequency of the ATP7B mutations, we described 77 clinically and biochemically confirmed WD patients and detected mutations in ten WD families from southwestern China. Clinical features were presented and all the exons of the ATP7B gene were screened. RESULTS The appearance of Kayser-Fleischer (K-F) rings was closely related to onset age, particularly before 10 years old. For those patients with predominantly neurological symptoms, MRI was the most sensitive and preferred examination. Eight mutations of the ATP7B gene were detected including seven reported mutations (c.2302dup, c.2304delC, c.2333 G>T, c.2621 C>T, c.2755 C>G, c.2975 C>T and c.1366 G>C) and four novel mutations (c.3446 G>A, c.3767insCA, c.3406 G>A and c.3700delG). c.2333 G>T was detected in 6/20 alleles (30%), accounting for the largest proportion, which could be regarded as a mutation hotspot in this region. CONCLUSIONS Our study extends the mutation spectrum of ATP7B and analyzes the relationship between mutations in the ATP7B gene and clinical findings of WD.
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Affiliation(s)
- Yu Liu
- Department of Medical Genetics, Third Military Medical University, Chongqing, P.R. China; The Second Battalion, Undergraduate Student Brigade, Third Military Medical University, Chongqing, P.R. China
| | - Hao Zhou
- Department of Medical Genetics, Third Military Medical University, Chongqing, P.R. China; The Second Battalion, Undergraduate Student Brigade, Third Military Medical University, Chongqing, P.R. China
| | - Hong Guo
- Department of Medical Genetics, Third Military Medical University, Chongqing, P.R. China.
| | - Yun Bai
- Department of Medical Genetics, Third Military Medical University, Chongqing, P.R. China
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16
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Coffey AJ, Durkie M, Hague S, McLay K, Emmerson J, Lo C, Klaffke S, Joyce CJ, Dhawan A, Hadzic N, Mieli-Vergani G, Kirk R, Elizabeth Allen K, Nicholl D, Wong S, Griffiths W, Smithson S, Giffin N, Taha A, Connolly S, Gillett GT, Tanner S, Bonham J, Sharrack B, Palotie A, Rattray M, Dalton A, Bandmann O. A genetic study of Wilson's disease in the United Kingdom. Brain 2013; 136:1476-87. [PMID: 23518715 PMCID: PMC3634195 DOI: 10.1093/brain/awt035] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Revised: 12/18/2012] [Accepted: 01/03/2013] [Indexed: 12/13/2022] Open
Abstract
Previous studies have failed to identify mutations in the Wilson's disease gene ATP7B in a significant number of clinically diagnosed cases. This has led to concerns about genetic heterogeneity for this condition but also suggested the presence of unusual mutational mechanisms. We now present our findings in 181 patients from the United Kingdom with clinically and biochemically confirmed Wilson's disease. A total of 116 different ATP7B mutations were detected, 32 of which are novel. The overall mutation detection frequency was 98%. The likelihood of mutations in genes other than ATP7B causing a Wilson's disease phenotype is therefore very low. We report the first cases with Wilson's disease due to segmental uniparental isodisomy as well as three patients with three ATP7B mutations and three families with Wilson's disease in two consecutive generations. We determined the genetic prevalence of Wilson's disease in the United Kingdom by sequencing the entire coding region and adjacent splice sites of ATP7B in 1000 control subjects. The frequency of all single nucleotide variants with in silico evidence of pathogenicity (Class 1 variant) was 0.056 or 0.040 if only those single nucleotide variants that had previously been reported as mutations in patients with Wilson's disease were included in the analysis (Class 2 variant). The frequency of heterozygote, putative or definite disease-associated ATP7B mutations was therefore considerably higher than the previously reported occurrence of 1:90 (or 0.011) for heterozygote ATP7B mutation carriers in the general population (P < 2.2 × 10(-16) for Class 1 variants or P < 5 × 10(-11) for Class 2 variants only). Subsequent exclusion of four Class 2 variants without additional in silico evidence of pathogenicity led to a further reduction of the mutation frequency to 0.024. Using this most conservative approach, the calculated frequency of individuals predicted to carry two mutant pathogenic ATP7B alleles is 1:7026 and thus still considerably higher than the typically reported prevalence of Wilson's disease of 1:30 000 (P = 0.00093). Our study provides strong evidence for monogenic inheritance of Wilson's disease. It also has major implications for ATP7B analysis in clinical practice, namely the need to consider unusual genetic mechanisms such as uniparental disomy or the possible presence of three ATP7B mutations. The marked discrepancy between the genetic prevalence and the number of clinically diagnosed cases of Wilson's disease may be due to both reduced penetrance of ATP7B mutations and failure to diagnose patients with this eminently treatable disorder.
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Affiliation(s)
| | - Miranda Durkie
- 2 Sheffield Diagnostic Genetics Service, Sheffield, S10 2TH, UK
| | - Stephen Hague
- 3 Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
| | - Kirsten McLay
- 1 Wellcome Trust Sanger Institute, Hinxton, CB10 1SA, UK
- 4 The Genome Analysis Centre, Norwich, NR4 7UH, UK
| | | | - Christine Lo
- 3 Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
| | - Stefanie Klaffke
- 3 Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
| | | | - Anil Dhawan
- 5 King’s College Hospital, London, SE5 9RS, UK
| | | | | | - Richard Kirk
- 2 Sheffield Diagnostic Genetics Service, Sheffield, S10 2TH, UK
| | | | - David Nicholl
- 6 Department of Neurology, Birmingham City Hospital, Birmingham, B18 7QH, UK
| | - Siew Wong
- 6 Department of Neurology, Birmingham City Hospital, Birmingham, B18 7QH, UK
| | | | | | - Nicola Giffin
- 9 Department of Neurology, Royal United Hospitals Bath, Bath, BA1 3NG, UK
| | - Ali Taha
- 10 University Hospital Crosshouse, Kilmarnock, KA2 0BE, UK
| | - Sally Connolly
- 11 Sheffield Children’s NHS Foundation Trust, Sheffield, S10 2TH, UK
| | - Godfrey T. Gillett
- 12 Department of Clinical Chemistry, Sheffield Teaching Hospitals, Sheffield, S5 7AU, UK
| | - Stuart Tanner
- 11 Sheffield Children’s NHS Foundation Trust, Sheffield, S10 2TH, UK
| | - Jim Bonham
- 11 Sheffield Children’s NHS Foundation Trust, Sheffield, S10 2TH, UK
| | - Basil Sharrack
- 3 Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
| | - Aarno Palotie
- 1 Wellcome Trust Sanger Institute, Hinxton, CB10 1SA, UK
- 13 Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, P.O. Box 20, Finland
- 14 Program in Medical and Population Genetics and Genetic Analysis Platform, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- 15 Department of Medical Genetics, University of Helsinki and University Central Hospital, P.O. Box 63, Helsinki, Finland
| | - Magnus Rattray
- 3 Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
| | - Ann Dalton
- 2 Sheffield Diagnostic Genetics Service, Sheffield, S10 2TH, UK
| | - Oliver Bandmann
- 3 Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
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17
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Incollu S, Lepori MB, Zappu A, Dessì V, Noli MC, Mameli E, Iorio R, Ranucci G, Cao A, Loudianos G. DNA and RNA studies for molecular characterization of a gross deletion detected in homozygosity in the NH2-terminal region of the ATP7B gene in a Wilson disease patient. Mol Cell Probes 2011; 25:195-8. [PMID: 21925265 DOI: 10.1016/j.mcp.2011.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 07/08/2011] [Accepted: 07/27/2011] [Indexed: 01/19/2023]
Abstract
Wilson disease is an autosomal recessive disorder caused by defective function of the copper transporting protein ATP7B. Approximately 520 Wilson disease-causing mutations have been described to date. In this study we report the use of DNA and RNA analysis for molecular characterization of a gross deletion of the ATP7B gene detected in homozygosity in a Wilson disease patient. The c.51+384_1708-953del mutation spans an 8798 bp region of the ATP7B gene from exon 2 to intron 4. The results obtained suggest that the combination of DNA and RNA analyses can be used for molecular characterization of gross ATP7B deletions, thus improving genetic counselling and diagnosis of Wilson disease. Moreover these studies, help to better establish the molecular mechanisms producing Wilson disease.
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Affiliation(s)
- Simona Incollu
- Dipartimento di Scienze Biomediche e Biotecnologie, USC, Cagliari, Italy
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18
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Tatsumi Y, Shinohara T, Imoto M, Wakusawa S, Yano M, Hayashi K, Hattori A, Hayashi H, Shimizu A, Ichiki T, Nakashima S, Katano Y, Goto H. Potential of the international scoring system for the diagnosis of Wilson disease to differentiate Japanese patients who need anti-copper treatment. Hepatol Res 2011; 41:887-96. [PMID: 21707886 DOI: 10.1111/j.1872-034x.2011.00835.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
AIM Patients with Wilson disease show complex clinical features. Accurate diagnosis at the initial clinical manifestation is important for patients to receive effective treatment with anti-copper agents. In this study, we assessed whether the international scoring system for the diagnosis of Wilson disease is a reliable tool for screening Japanese patients with primary copper toxicosis requiring anti-copper treatment. METHODS Twenty-three Japanese patients suspected of Wilson disease were enrolled in this study. We performed long-range polymerase chain reaction to detect ATP7B mutations in this series. Finally, we retrospectively assessed the reliability of using a diagnostic score of 4 or more points as the cut-off for this scoring system. RESULTS Ten patients were homozygous or compound heterozygous for ATP7B mutations including a novel mutation of 3837 bp deletion including 3 exons. The mutation would have been missed by the traditional analysis. Six patients were heterozygous for ATP7B mutations. Three of these six patients had additional diagnostic points. The other three patients were diagnosed as carriers of a mutant gene based on their low scores. One of the seven patients free from ATP7B mutation was affected by copper toxicosis. Though the score was 3 points based on increased urinary copper and copper-positive cirrhosis, anti-copper treatment promptly improved liver failure, which was likely due to idiopathic copper toxicosis. CONCLUSION The international scoring system for diagnosis of Wilson disease is a fairly reliable tool for screening Japanese patients who need anti-copper treatment. Caution is needed for patients with possible idiopathic copper toxicosis because the maximal score is 4 points.
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Affiliation(s)
- Yasuaki Tatsumi
- Department of Medicine, Aichi Gakuin University School of Pharmacy Division of Medical Technology, Nagoya University School of Health Sciences Department of Internal Medicine, Division of Gastroenterology, Nagoya University Graduate School of Medicine, Nagoya Department of Pediatrics, Kainan Hospital, Aichi Department of Internal Medicine, Kariya Toyota General Hospital, Kariya Department of Internal Medicine, Yokkaichi Municipal Hospital, Yokkaichi, Japan
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19
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Lee BH, Kim JH, Lee SY, Jin HY, Kim KJ, Lee JJ, Park JY, Kim GH, Choi JH, Kim KM, Yoo HW. Distinct clinical courses according to presenting phenotypes and their correlations to ATP7B mutations in a large Wilson's disease cohort. Liver Int 2011; 31:831-9. [PMID: 21645214 DOI: 10.1111/j.1478-3231.2011.02503.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION AND AIMS Wide phenotypic and genotypic heterogeneities in Wilson's disease (WD) have been reported, hampering the study of their correlations. The goal of this study was to identify the factors related to these diversities. METHODS Clinical courses and molecular genetic characteristics were analysed in 237 unrelated Korean WD families. The average follow-up period was 8.2 ± 5.8 years. RESULTS Presenting phenotypes were classified as H1 (12.2%), H2 (42.4%), N1 (21.6%), N2 (0.4%), NX (0.4%), presymptomatic (22.4%) and other (0.4%), modifying the guidelines by Ferenci and colleagues. Age at presentation was youngest and cirrhosis was rarest in the presymptomatic group. Decompensated cirrhosis was the highest in the H1 group. Favourable outcome was rarest in the N1 group. Forty-seven (11 novel) ATP7B mutations were identified in 85% of the 474 alleles. Multiplex ligation-dependent probe amplification assays in ATP7B and analyses of ATOX1 and COMMD1 genes identified no additional mutations. Yeast complementation assays demonstrated functional perturbation of the seven novel missense mutants. Five major mutations, p.Arg778Leu, p.Ala874Val, p.Asn1270Ser, p.Lys838SerfsX35 and p.Leu1083Phe, accounted for 63% of the alleles. H1 was more common, age at presentation was younger and N1+N2+NX tended to be less common in patients with nonsense, frame shifting or splicing mutations than in those with missense mutations alone. Patients with both mutations in the transduction (Td) or the ATP hinge domain showed presymptomatic or hepatic manifestations but no neurological manifestation. CONCLUSIONS The presenting phenotype strongly affects the clinical outcome of WD, and is related to the ATP7B mutation type and location, providing an evidence for genotype-phenotype correlations in WD.
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Affiliation(s)
- Beom H Lee
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
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20
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Clinical presentation and mutations in Danish patients with Wilson disease. Eur J Hum Genet 2011; 19:935-41. [PMID: 21610751 DOI: 10.1038/ejhg.2011.80] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
This study describes the clinical presentation and diagnosis in all Danish patients (49, 41 unrelated) with Wilson disease (WND). On the basis of the number of diagnosed patients from 1990-2008, the prevalence was estimated to be 1:49 500. Among routinely used diagnostic tests, none were consistently indicative of WND, with the exception of the 24-h urine-Cu test, which is always outside the normal range. Mutations were identified in 100% of the screened ATP7B alleles (70 unrelated), including five novel mutations: p.1021K; p.G1158V; p.L1304F; IVS20-2A>G; Ex5_6del. In all, 70% of mutations were found in exons 8, 14, 17, 18, and 20. The most frequent mutation, p.H1069Q, comprised 18%. We propose a new and simple model that correlates genotype and age of onset. By assuming that the milder of two mutations is 'functionally dominant' and determines the age of onset, we classified 25/27 mutations as either severe (age of onset <20 years) or moderate (age of onset >20 years), and correctly predicted the age of onset in 37/39 patients. This method should be tested in other Wilson populations.
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21
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Behari M, Pardasani V. Genetics of Wilsons disease. Parkinsonism Relat Disord 2010; 16:639-44. [PMID: 20708958 DOI: 10.1016/j.parkreldis.2010.07.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 07/06/2010] [Accepted: 07/07/2010] [Indexed: 02/03/2023]
Abstract
Wilson's disease is a rare autosomal recessive disorder of copper transport due to mutations in the ATP7B gene, responsible for transport of copper into bile from hepatocytes and its incorporation into apoceruloplasmin to form ceruloplasmin resulting in excessive accumulation of copper in the liver and extrahepatic tissues. Clinical features of WD result from toxic accumulation of copper in liver, brain and kidney. Early diagnosis is mandatory to initiate early treatment to prevent morbidity and mortality. More than 400 mutations have been reported, some of which are rather characteristic of geographical regions and ethnic population. Genetic testing is not useful as a routine procedure, but has its role in at risk individuals such as siblings and children of probands and in individuals with suggestive symptoms but where other tests are contradictory.
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Affiliation(s)
- Madhuri Behari
- Department of Neurology, All India Institute of Medical Sciences, New Delhi 110029, India.
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22
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Leggio L, Addolorato G, Loudianos G, Abenavoli L, Gasbarrini G. Genotype-phenotype correlation of the Wilson disease ATP7B gene. Am J Med Genet A 2009; 140:933. [PMID: 16532467 DOI: 10.1002/ajmg.a.31191] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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23
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Leggio L, Malandrino N, Loudianos G, Abenavoli L, Lepori MB, Capristo E, De Virgiliis S, Gasbarrini G, Addolorato G. Analysis of the T1288R mutation of the Wilson disease ATP7B gene in four generations of a family: possible genotype-phenotype correlation with hepatic onset. Dig Dis Sci 2007; 52:2570-5. [PMID: 17410460 DOI: 10.1007/s10620-006-9666-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Accepted: 10/31/2006] [Indexed: 12/16/2022]
Abstract
Wilson disease, an autosomal recessive disorder due to mutations of the ATP7B gene, is characterized by copper accumulation and toxicity in the liver and subsequently in other organs, mainly the brain and cornea. A new missense mutation (T1288R) of the ATP7B gene has recently been discovered in a Wilson disease patient in our laboratory. The aim of the present study was to analyze clinical and genetic features of more generations of the family of the patient in which the new mutation T1288R was discovered. A total of 19 subjects were studied; in particular, four generations of the patient's family were analyzed. The ATP7B gene was analyzed by single-strand conformational polymorphism followed by direct sequencing. Two brothers presented a clinical diagnosis of Wilson disease with an hepatic phenotype and a genotype characterized by the homozygotic mutation T1288R. The heterozygotic mutation T1288R was found in seven subjects belonging to all four generations. The present study represents the first screening for a Wilson disease mutation through four generations of a nonconsanguineous family. All the patients with the homozygotic T1288R mutation in the present pedigree presented an hepatic phenotype without a neurological presentation. Consequently, a genotype-phenotype correlation could be hypothesized, although further studies are necessary to clarify this topic.
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Affiliation(s)
- Lorenzo Leggio
- Institute of Internal Medicine, Catholic University of Rome, Gemelli Hospital, L. go Gemelli 8, 00168, Rome, Italy.
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