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Martinez-Fierro ML, Cabral-Pacheco GA, Garza-Veloz I, Acuña-Quiñones J, Martinez-de-Villarreal LE, Ibarra-Ramirez M, Beuten J, Sanchez-Guerrero SE, Villarreal-Martinez L, Delgado-Enciso I, Rodriguez-Sanchez IP, Zuñiga-Ramirez VZ, Cardenas-Vargas E, Romero-Diaz V. Whole-Exome Sequencing, Proteome Landscape, and Immune Cell Migration Patterns in a Clinical Context of Menkes Disease. Genes (Basel) 2021; 12:genes12050744. [PMID: 34069220 PMCID: PMC8156642 DOI: 10.3390/genes12050744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/12/2021] [Accepted: 05/12/2021] [Indexed: 11/18/2022] Open
Abstract
Menkes disease (MD) is a rare and often lethal X-linked recessive syndrome, characterized by generalized alterations in copper transport and metabolism, linked to mutations in the ATPase copper transporting α (ATP7A) gene. Our objective was to identify genomic alterations and circulating proteomic profiles related to MD assessing their potential roles in the clinical features of the disease. We describe the case of a male patient of 8 months of age with silvery hair, tan skin color, hypotonia, alterations in neurodevelopment, presence of seizures, and low values of plasma ceruloplasmin. Trio-whole-exome sequencing (Trio-WES) analysis, plasma proteome screening, and blood cell migration assays were carried out. Trio-WES revealed a hemizygous change c.4190C > T (p.S1397F) in exon 22 of the ATP7A gene. Compared with his parents and with child controls, 11 plasma proteins were upregulated and 59 downregulated in the patient. According to their biological processes, 42 (71.2%) of downregulated proteins had a participation in cellular transport. The immune system process was represented by 35 (59.3%) downregulated proteins (p = 9.44 × 10−11). Additional studies are necessary to validate these findings as hallmarks of MD.
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Affiliation(s)
- Margarita L. Martinez-Fierro
- Molecular Medicine Laboratory, Unidad Académica de Medicina Humana y C.S, Universidad Autónoma de Zacatecas, Carretera Zacatecas-Guadalajara Km.6, Ejido la Escondida, Zacatecas 98160, Mexico; (G.A.C.-P.); (I.G.-V.); (J.A.-Q.); (V.Z.Z.-R.)
- Correspondence: ; Tel.: +52-(492)-925-6690 (ext. 4511)
| | - Griselda A. Cabral-Pacheco
- Molecular Medicine Laboratory, Unidad Académica de Medicina Humana y C.S, Universidad Autónoma de Zacatecas, Carretera Zacatecas-Guadalajara Km.6, Ejido la Escondida, Zacatecas 98160, Mexico; (G.A.C.-P.); (I.G.-V.); (J.A.-Q.); (V.Z.Z.-R.)
| | - Idalia Garza-Veloz
- Molecular Medicine Laboratory, Unidad Académica de Medicina Humana y C.S, Universidad Autónoma de Zacatecas, Carretera Zacatecas-Guadalajara Km.6, Ejido la Escondida, Zacatecas 98160, Mexico; (G.A.C.-P.); (I.G.-V.); (J.A.-Q.); (V.Z.Z.-R.)
| | - Jesus Acuña-Quiñones
- Molecular Medicine Laboratory, Unidad Académica de Medicina Humana y C.S, Universidad Autónoma de Zacatecas, Carretera Zacatecas-Guadalajara Km.6, Ejido la Escondida, Zacatecas 98160, Mexico; (G.A.C.-P.); (I.G.-V.); (J.A.-Q.); (V.Z.Z.-R.)
| | - Laura E. Martinez-de-Villarreal
- Departamento de Genética, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico; (L.E.M.-d.-V.); (M.I.-R.)
| | - Marisol Ibarra-Ramirez
- Departamento de Genética, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico; (L.E.M.-d.-V.); (M.I.-R.)
| | - Joke Beuten
- AiLife Diagnostics, 1920 Country Pl Pkwy Suite 100, Pearland, TX 77584, USA;
| | - Samantha E. Sanchez-Guerrero
- Hospital General Zacatecas “Luz González Cosío”, Servicios de Salud de Zacatecas, Zacatecas 98160, Mexico; (S.E.S.-G.); (E.C.-V.)
| | - Laura Villarreal-Martinez
- Hematology Service, Hospital Universitario “Dr. José Eleuterio González”, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico;
| | - Ivan Delgado-Enciso
- Department of Molecular Medicine, School of Medicine, University of Colima, Colima 28040, Mexico;
| | - Iram P. Rodriguez-Sanchez
- Molecular and Structural Physiology Laboratory, School of Biological Sciences, Autonomous University of Nuevo León, Monterrey 64460, Mexico;
| | - Vania Z. Zuñiga-Ramirez
- Molecular Medicine Laboratory, Unidad Académica de Medicina Humana y C.S, Universidad Autónoma de Zacatecas, Carretera Zacatecas-Guadalajara Km.6, Ejido la Escondida, Zacatecas 98160, Mexico; (G.A.C.-P.); (I.G.-V.); (J.A.-Q.); (V.Z.Z.-R.)
| | - Edith Cardenas-Vargas
- Hospital General Zacatecas “Luz González Cosío”, Servicios de Salud de Zacatecas, Zacatecas 98160, Mexico; (S.E.S.-G.); (E.C.-V.)
| | - Viktor Romero-Diaz
- Department of Histology, Universidad Autónoma de Nuevo León, Facultad de Medicina, Monterrey 64460, Mexico;
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Møller LB, Mogensen M, Weaver DD, Pedersen PA. Occipital Horn Syndrome as a Result of Splice Site Mutations in ATP7A. No Activity of ATP7A Splice Variants Missing Exon 10 or Exon 15. Front Mol Neurosci 2021; 14:532291. [PMID: 33967692 PMCID: PMC8097048 DOI: 10.3389/fnmol.2021.532291] [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: 10/14/2020] [Accepted: 03/12/2021] [Indexed: 11/13/2022] Open
Abstract
Disease-causing variants in ATP7A lead to two different phenotypes associated with copper deficiency; a lethal form called Menkes disease (MD), leading to early death, and a much milder form called occipital horn syndrome (OHS). Some investigators have proposed that an ATP7A transcript missing exon 10 leads to a partly active protein product resulting in the OHS phenotype. Here, we describe an individual with OHS, a biology professor, who survived until age 62 despite a splice site mutation, leading to skipping of exon 15. ATP7A transcripts missing exon 10, or exon 15 preserve the reading frame, but it is unknown if either of these alternative transcripts encode functional protein variants. We have investigated the molecular consequence of splice site mutations leading to skipping of exon 10 or exon 15 which have been identified in individuals with OHS, or MD. By comparing ATP7A expression in fibroblasts from three individuals with OHS (OHS-fibroblasts) to ATP7A expression in fibroblasts from two individuals with MD (MD-fibroblasts), we demonstrate that transcripts missing either exon 10 or exon 15 were present in similar amounts in OHS-fibroblasts and MD-fibroblasts. No ATP7A protein encoded from these transcripts could be detected in the OHS and MD fibroblast. These results, combined with the observation that constructs encoding ATP7A cDNA sequences missing either exon 10, or exon 15 were unable to complement the high iron requirement of the ccc2Δ yeast strain, provide evidence that neither a transcript missing exon 10 nor a transcript missing exon 15 results in functional ATP7A protein. In contrast, higher amounts of wild-type ATP7A transcript were present in the OHS-fibroblasts compared with the MD-fibroblasts. We found that the MD-fibroblasts contained between 0 and 0.5% of wild-type ATP7A transcript, whereas the OHS-fibroblasts contained between 3 and 5% wild-type transcripts compared with the control fibroblasts. In summary these results indicate that protein variants encoded by ATP7A transcripts missing either exon 10 or exon 15 are not functional and not responsible for the OHS phenotype. In contrast, expression of only 3-5% of wild-type transcript compared with the controls permits the OHS phenotype.
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Affiliation(s)
- Lisbeth Birk Møller
- Department of Clinical Genetics, Applied Human Molecular Genetics, Kennedy Center, Copenhagen University Hospital, Glostrup, Denmark
| | - Mie Mogensen
- Department of Clinical Genetics, Applied Human Molecular Genetics, Kennedy Center, Copenhagen University Hospital, Glostrup, Denmark
| | - David D Weaver
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States
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Mhaske A, Dileep K, Kumar M, Poojary M, Pandhare K, Zhang KY, Scaria V, Binukumar B. ATP7A Clinical Genetics Resource - A comprehensive clinically annotated database and resource for genetic variants in ATP7A gene. Comput Struct Biotechnol J 2020; 18:2347-2356. [PMID: 32994893 PMCID: PMC7501406 DOI: 10.1016/j.csbj.2020.08.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 12/21/2022] Open
Abstract
ATP7A is a critical copper transporter involved in Menkes Disease, Occipital horn Syndrome and X-linked distal spinal muscular atrophy type 3 which are X linked genetic disorders. These are rare diseases and their genetic epidemiology of the diseases is unknown. A number of genetic variants in the genes have been reported in published literature as well as databases, however, understanding the pathogenicity of variants and genetic epidemiology requires the data to be compiled in a unified format. To this end, we systematically compiled genetic variants from published literature and datasets. Each of the variants were systematically evaluated for evidences with respect to their pathogenicity and classified as per the American College of Medical Genetics and the Association of Molecular Pathologists (ACMG-AMP) guidelines into Pathogenic, Likely Pathogenic, Benign, Likely Benign and Variants of Uncertain Significance. Additional integrative analysis of population genomic datasets provides insights into the genetic epidemiology of the disease through estimation of carrier frequencies in global populations. To deliver a mechanistic explanation for the pathogenicity of selected variants, we also performed molecular modeling studies. Our modeling studies concluded that the small structural distortions observed in the local structures of the protein may lead to the destabilization of the global structure. To the best of our knowledge, ATP7A Clinical Genetics Resource is one of the most comprehensive compendium of variants in the gene providing clinically relevant annotations in gene.
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Affiliation(s)
- Aditi Mhaske
- CSIR Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110 025, India
| | - K.V. Dileep
- Laboratory for Structural Bioinformatics, Center for Biosystems Dynamics Research, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - Mukesh Kumar
- CSIR Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110 025, India
- Academy of Scientific and Innovative Research, CSIR-IGIB South Campus, Mathura Road, Delhi, India
| | - Mukta Poojary
- CSIR Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110 025, India
- Academy of Scientific and Innovative Research, CSIR-IGIB South Campus, Mathura Road, Delhi, India
| | - Kavita Pandhare
- CSIR Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110 025, India
- Academy of Scientific and Innovative Research, CSIR-IGIB South Campus, Mathura Road, Delhi, India
| | - Kam Y.J. Zhang
- Laboratory for Structural Bioinformatics, Center for Biosystems Dynamics Research, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - Vinod Scaria
- CSIR Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110 025, India
- Academy of Scientific and Innovative Research, CSIR-IGIB South Campus, Mathura Road, Delhi, India
- Corresponding author at: CSIR-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, Sukhdev Vihar, New Delhi 110025, India.
| | - B.K. Binukumar
- CSIR Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110 025, India
- Academy of Scientific and Innovative Research, CSIR-IGIB South Campus, Mathura Road, Delhi, India
- Corresponding author at: CSIR-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, Sukhdev Vihar, New Delhi 110025, India.
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Fujisawa C, Kodama H, Hiroki T, Akasaka Y, Hamanoue M. ATP7A mutations in 66 Japanese patients with Menkes disease and carrier detection: A gene analysis. Pediatr Int 2019; 61:345-350. [PMID: 30809870 DOI: 10.1111/ped.13817] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 01/07/2019] [Accepted: 02/23/2019] [Indexed: 12/25/2022]
Abstract
BACKGROUND Menkes disease (MNK; MIN 309400) is an X-linked recessive lethal disorder of copper metabolism caused by mutations in ATP7A (MIM 300011), which encodes a transmembrane copper-transporting P-type ATPase. This study assessed mutations in ATP7A in Japanese patients with MNK and their families using gene analysis. METHODS A total of 66 patients with MNK born between 1975 and 2013 in Japan were investigated in this study. Definite diagnosis of MNK was carried out on polymerase chain reaction (PCR) amplification and direct sequencing of each exon. Genetic analysis was also performed on 39 women for carrier diagnosis, and on nine fetuses and 10 neonates for the diagnosis of MNK. RESULTS We detected 55 different mutations, of which 20 were de novo mutations. The mutations were located around the six copper binding sites, first to third and six transmembrane domains, and the ATP binding site. Of 30 mothers, 23 (76.7%) were carriers. Approximately half of the male siblings of patients with MNK were also diagnosed with MNK. CONCLUSION Mutations in ATP7A varied widely across patients, although approximately half of the mutations were located in exons 4, 9, 10, and 15. Approximately 23% of patients did not inherit the mutations from their mothers, but had de novo mutations. An early definite diagnosis is necessary for the early treatment of MNK, and gene analysis serves as an effective method for detecting mutations in ATP7A.
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Affiliation(s)
- Chie Fujisawa
- Department of Pediatrics, Teikyo University School of Medicine, Tokyo, Japan
| | - Hiroko Kodama
- Department of Pediatrics, Teikyo University School of Medicine, Tokyo, Japan.,Department of Health and Nutrition, Faculty of Health and Medical Science, Teikyo Heisei University, Tokyo, Japan
| | - Tomoko Hiroki
- Department of Pediatrics, Teikyo University School of Medicine, Tokyo, Japan
| | - Yoshikiyo Akasaka
- Regenerative Disease Research Unit, Advanced Research Center, Toho University, Tokyo, Japan
| | - Makoto Hamanoue
- Department of Physiology, Toho University School of Medicine, Tokyo, Japan
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de Gemmis P, Enzo MV, Lorenzetto E, Cattelan P, Segat D, Hladnik U. 13 novel putative mutations in ATP7A found in a cohort of 25 Italian families. Metab Brain Dis 2017; 32:1173-1183. [PMID: 28451781 DOI: 10.1007/s11011-017-0010-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 04/03/2017] [Indexed: 01/09/2023]
Abstract
ATP7A is a copper-transporting P-type adenosine triphosphatase whose loss of function leads to the Menkes disease, an X-linked copper metabolism multi-organ disorder (1 in 100.000 births). Here we document our experience with the ATP7A linked diseases in Italy. We analyzed the exonic structure of the ATP7A gene in 25 unrelated Italian families and studied the variants of unknown significance. We identified 22 different DNA alterations, 13 of which first reported in this study. The classical Menkes phenotype was present in 21 of the 25 families and was linked with highly damaging mutations (7 nonsense; 4 frame-shift; 2 small in-frame deletions, 2 splice site alterations, 2 gross deletions, and 1 gross duplication). Of the 4 cases with milder variants of the Menkes disease two had a missense mutation, one a leaky splice site alteration and one a nonsense mutation in exon 22. We determined in silico that all the mutations leading to the classical Menkes disease leave no residual activity of ATP7A including the apparently less severe in-frame deletions. Whereas milder forms of the disease are characterized by mutations that allow a limited residual activity of ATP7A, including the nonsense mutation observed.
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Affiliation(s)
- Paola de Gemmis
- "Mauro Baschirotto" Institute for Rare Diseases - B.I.R.D. Foundation n.p.o., via B. Bizio, 1 36023, Costozza di Longare, Vicenza, Italy
| | - Maria Vittoria Enzo
- "Mauro Baschirotto" Institute for Rare Diseases - B.I.R.D. Foundation n.p.o., via B. Bizio, 1 36023, Costozza di Longare, Vicenza, Italy
| | - Elisa Lorenzetto
- "Mauro Baschirotto" Institute for Rare Diseases - B.I.R.D. Foundation n.p.o., via B. Bizio, 1 36023, Costozza di Longare, Vicenza, Italy
| | - Paola Cattelan
- "Mauro Baschirotto" Institute for Rare Diseases - B.I.R.D. Foundation n.p.o., via B. Bizio, 1 36023, Costozza di Longare, Vicenza, Italy
| | - Daniela Segat
- "Mauro Baschirotto" Institute for Rare Diseases - B.I.R.D. Foundation n.p.o., via B. Bizio, 1 36023, Costozza di Longare, Vicenza, Italy
| | - Uros Hladnik
- "Mauro Baschirotto" Institute for Rare Diseases - B.I.R.D. Foundation n.p.o., via B. Bizio, 1 36023, Costozza di Longare, Vicenza, Italy.
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6
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Bonati MT, Verde F, Hladnik U, Cattelan P, Campana L, Castronovo C, Ticozzi N, Maderna L, Colombrita C, Papa S, Banfi P, Silani V. A novel nonsense ATP7A pathogenic variant in a family exhibiting a variable occipital horn syndrome phenotype. Mol Genet Metab Rep 2017; 13:14-17. [PMID: 28761814 PMCID: PMC5522958 DOI: 10.1016/j.ymgmr.2017.07.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/14/2017] [Accepted: 07/14/2017] [Indexed: 10/26/2022] Open
Abstract
We report on a family with occipital horn syndrome (OHS) diagnosed in the proband's late fifties. A novel ATP7A pathogenic variant (c.4222A > T, p.(Lys1408*)), representing the first nonsense variant and the second late truncation causing OHS rather than classic Menkes disease, was found to segregate in the family. The predicted maintenance of transmembrane domains is consistent with a residual protein activity, which may explain the mild clinical presentation.
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Affiliation(s)
- Maria Teresa Bonati
- Clinic of Medical Genetics, IRCCS Istituto Auxologico Italiano, Ospedale San Luca, piazzale Brescia 20, 20149 Milan, Italy
| | - Federico Verde
- Neurology Unit and Laboratory of Neuroscience, IRCCS Istituto Auxologico Italiano, Ospedale San Luca, piazzale Brescia 20, 20149 Milan, Italy.,Department of Pathophysiology and Transplantation, Dino Ferrari Center, University of Milan Medical School, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, via Francesco Sforza 28, 20122 Milan, Italy
| | - Uros Hladnik
- Laboratory of Medical Genetics, Mauro Baschirotto Institute for Rare Diseases, Via Bartolomeo Bizio 1, 36023 Costozza di Longare (Vicenza), Italy
| | - Paola Cattelan
- Laboratory of Medical Genetics, Mauro Baschirotto Institute for Rare Diseases, Via Bartolomeo Bizio 1, 36023 Costozza di Longare (Vicenza), Italy
| | - Luca Campana
- Neurology Unit and Laboratory of Neuroscience, IRCCS Istituto Auxologico Italiano, Ospedale San Luca, piazzale Brescia 20, 20149 Milan, Italy
| | - Chiara Castronovo
- Laboratory of Medical Cytogenetics and Molecular Genetics, IRCCS Istituto Auxologico Italiano, via L. Ariosto 13, 20145 Milan, Italy
| | - Nicola Ticozzi
- Neurology Unit and Laboratory of Neuroscience, IRCCS Istituto Auxologico Italiano, Ospedale San Luca, piazzale Brescia 20, 20149 Milan, Italy.,Department of Pathophysiology and Transplantation, Dino Ferrari Center, University of Milan Medical School, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, via Francesco Sforza 28, 20122 Milan, Italy
| | - Luca Maderna
- Neurology Unit and Laboratory of Neuroscience, IRCCS Istituto Auxologico Italiano, Ospedale San Luca, piazzale Brescia 20, 20149 Milan, Italy
| | - Claudia Colombrita
- Neurology Unit and Laboratory of Neuroscience, IRCCS Istituto Auxologico Italiano, Ospedale San Luca, piazzale Brescia 20, 20149 Milan, Italy
| | - Sergio Papa
- Unit of Diagnostic Imaging and Stereotactic Radiosurgery, Centro Diagnostico Italiano, Via Saint Bon 20, 20147 Milan, Italy
| | - Paolo Banfi
- Don Carlo Gnocchi Foundation IRCCS-ONLUS, Piazzale Morandi 6, 20121 Milan, Italy
| | - Vincenzo Silani
- Neurology Unit and Laboratory of Neuroscience, IRCCS Istituto Auxologico Italiano, Ospedale San Luca, piazzale Brescia 20, 20149 Milan, Italy.,Department of Pathophysiology and Transplantation, Dino Ferrari Center, University of Milan Medical School, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, via Francesco Sforza 28, 20122 Milan, Italy
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Abstract
Disorders of copper homeostasis are currently recognized across the life span. Their recognition and links to human disease have spanned several decades, beginning with the recognition of a degenerative disorder in the offspring of sheep grazing in copper-deficient pastures, through to the description of infants suffering from a progressive neurodegenerative disorder characterized by epileptic seizures, developmental regression, failure to thrive, and an unusual hair quality (giving the condition its distinctive label of “kinky hair disease”). In this review, we trace the historical background and describe the biochemistry and physiology of copper metabolism and transport, inheritance patterns, molecular genetics, and genotype–phenotype correlations based on current understanding of the disorder. It is clear from the clinical presentations and variants that disorders of copper homeostasis include phenotypes ranging from mild occipital horn syndrome to intermediate and severe forms of classical Menkes disease. The symptoms involve multiple organ systems such as brain, lung, gastrointestinal tract, urinary tract, connective tissue, and skin. A multisystem disorder needs a multidisciplinary approach to care, as treatment interventions permit longer survival for some individuals. Animal models have been developed to help screen treatment options and provide a better understanding of these disorders in the laboratory. Finally, we propose a multidisciplinary approach to promote continued research (both basic and clinical) to improve survival, quality of life, and care for these conditions.
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Affiliation(s)
| | - Asuri N Prasad
- Department of Pediatrics; Section of Pediatric Neurology; Division of Clinical Neurological Sciences; Child Health Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
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Perez-Siles G, Grant A, Ellis M, Ly C, Kidambi A, Khalil M, Llanos RM, Fontaine SL, Strickland AV, Züchner S, Bermeo S, Neist E, Brennan-Speranza TC, Takata RI, Speck-Martins CE, Mercer JFB, Nicholson GA, Kennerson ML. Characterizing the molecular phenotype of an Atp7a(T985I) conditional knock in mouse model for X-linked distal hereditary motor neuropathy (dHMNX). Metallomics 2016; 8:981-92. [PMID: 27293072 DOI: 10.1039/c6mt00082g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
ATP7A is a P-type ATPase essential for cellular copper (Cu) transport and homeostasis. Loss-of-function ATP7A mutations causing systemic Cu deficiency are associated with severe Menkes disease or its milder allelic variant, occipital horn syndrome. We previously identified two rare ATP7A missense mutations (P1386S and T994I) leading to a non-fatal form of motor neuron disorder, X-linked distal hereditary motor neuropathy (dHMNX), without overt signs of systemic Cu deficiency. Recent investigations using a tissue specific Atp7a knock out model have demonstrated that Cu plays an essential role in motor neuron maintenance and function, however the underlying pathogenic mechanisms of ATP7A mutations causing axonal degeneration remain unknown. We have generated an Atp7a conditional knock in mouse model of dHMNX expressing Atp7a(T985I), the orthologue of the human ATP7A(T994I) identified in dHMNX patients. Although a degenerative motor phenotype is not observed, the knock in Atp7a(T985I/Y) mice show altered Cu levels within the peripheral and central nervous systems, an increased diameter of the muscle fibres and altered myogenin and myostatin gene expression. Atp7a(T985I/Y) mice have reduced Atp7a protein levels and recapitulate the defective trafficking and altered post-translational regulatory mechanisms observed in the human ATP7A(T994I) patient fibroblasts. Our model provides a unique opportunity to characterise the molecular phenotype of dHMNX and the time course of cellular events leading to the process of axonal degeneration in this disease.
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Affiliation(s)
- Gonzalo Perez-Siles
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Concord, NSW, Australia
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Tandem Duplication of Exons 1-7 Neither Impairs ATP7A Expression Nor Causes a Menkes Disease Phenotype. JIMD Rep 2015. [PMID: 25638460 DOI: 10.1007/8904_2014_391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] Open
Abstract
ATP7A duplications are estimated to represent the molecular cause of Menkes disease in 4-10% of affected patients. We identified a novel duplication of ATP7A exons 1-7 discovered in the context of a challenging prenatal diagnostic situation. All other reported ATP7A duplications (n = 24) involved intragenic tandem duplications, predicted to disrupt the normal translational reading frame and produce nonfunctional ATP7A proteins. In contrast, the exon 1-7 duplication occurred at the 5' end of the ATP7A gene rather than within the gene and did not correspond to any known copy number variants. We hypothesized that, if the exon 1-7 duplication was in tandem, functional ATP7A molecules could be generated depending on promoter selection, mRNA splicing, and the proximal and distal duplication breakpoints and that Menkes disease would be averted. Here, we present detailed molecular characterization of this novel duplication, as well as 2-year postnatal clinical and biochemical correlations. The case highlights the ongoing need for cautious interpretation of prenatal genetic test results.
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10
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Møller LB. Small amounts of functional ATP7A protein permit mild phenotype. J Trace Elem Med Biol 2015; 31:173-7. [PMID: 25172213 DOI: 10.1016/j.jtemb.2014.07.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 06/11/2014] [Accepted: 07/03/2014] [Indexed: 11/15/2022]
Abstract
Mutations in ATP7A lead to at least three allelic disorders: Menkes disease (MD), Occipital horn syndrome and X-linked distal motor neuropathy. These disorders are mainly seen in male individuals, but a few affected females have been described. More than 400 different mutations have been identified in the ATP7A gene. We have conducted several studies in the hope of uncovering the relationship between genotype and phenotype. We have examined the X-inactivation pattern in affected females, the effect of exon-deletions and--duplications, and splice-site mutations on the composition and amount of ATP7A transcript, and we have examined the structural location of missense mutations. The X-inactivation pattern did not fully explain the manifestation of MD in a small fraction of carriers. Most of the affected females had preferential inactivation of the X-chromosome with the normal ATP7A gene, but a few individuals exhibited preferential inactivation of the X-chromosome with the mutated ATP7A gene. The observed mild phenotype in some patients with mutations that effect the composition of the ATP7A transcript, seems to be explained by the presence of a small amount of normal ATP7A transcript. The location of missense mutations on structural models of the ATP7A protein suggests that affected conserved residues generally lead to a severe phenotype. The ATP7A protein traffics within the cells. At low copper levels, ATP7A locates to the Trans-Golgi Network (TGN) to load cuproenzymes with copper, whereas at higher concentrations, ATP7A shifts to the post-Golgi compartments or to the plasma membrane to export copper out of the cell. Impaired copper-regulation trafficking has been observed for ATP7A mutants, but its impact on the clinical outcome is not clear. The major problem in patients with MD seems to be insufficient amounts of copper in the brain. In fact, prenatal treatment of mottled mice as a model for human MD with a combination of chelator and copper, produces a slight increase in copper levels in the brain which perhaps leads to longer survival and more active behavior. In conclusion, small amounts of copper at the right location seem to relieve the symptoms.
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Affiliation(s)
- Lisbeth Birk Møller
- Center for Applied Human Genetics, Kennedy Center, Rigshospitalet, Gl. Landevej 7, 2600 Glostrup, Denmark.
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Schoonveld C, Donsante A, del Gaudio D, Waggoner D, Das S, Kaler SG. Prenatal diagnostic conundrum involving a novel ATP7A duplication. Clin Genet 2012; 84:97-8. [PMID: 23151012 DOI: 10.1111/cge.12041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 10/10/2012] [Accepted: 10/11/2012] [Indexed: 11/30/2022]
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León-García G, Santana A, Villegas-Sepúlveda N, Pérez-González C, Henrríquez-Esquíroz JM, de León-García C, Wong C, Baeza I. The T1048I mutation in ATP7A gene causes an unusual Menkes disease presentation. BMC Pediatr 2012; 12:150. [PMID: 22992316 PMCID: PMC3489546 DOI: 10.1186/1471-2431-12-150] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Accepted: 08/17/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The ATP7A gene encodes the ATP7A protein, which is a trans-Golgi network copper transporter expressed in the brain and other organs. Mutations in this gene cause disorders of copper metabolism, such as Menkes disease. Here we describe the novel and unusual mutation (p.T1048I) in the ATP7A gene of a child with Menkes disease. The mutation affects a conserved DKTGT1048 phosphorylation motif that is involved in the catalytic activity of ATP7A. We also describe the clinical course and the response to copper treatment in this patient. CASE PRESENTATION An 11-month-old male Caucasian infant was studied because of hypotonia, ataxia and global developmental delay. The patient presented low levels of serum copper and ceruloplasmin, and was shown to be hemizygous for the p.T1048I mutation in ATP7A. The diagnosis was confirmed when the patient was 18 months old, and treatment with copper-histidinate (Cu-His) was started immediately. The patient showed some neurological improvement and he is currently 8 years old. Because the p.T1048I mutation affects its catalytic site, we expected a complete loss of functional ATP7A and a classical Menkes disease presentation. However, the clinical course of the patient was mild, and he responded to Cu-His treatment, which suggests that this mutation leads to partial conservation of the activity of ATP7A. CONCLUSION This case emphasizes the important correlation between genotype and phenotype in patients with Menkes disease. The prognosis in Menkes disease is associated with early detection, early initiation of treatment and with the preservation of some ATP7A activity, which is necessary for Cu-His treatment response. The description of this new mutation and the response of the patient to Cu-His treatment will contribute to the growing body of knowledge about treatment response in Menkes disease.
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Affiliation(s)
- Gregorio León-García
- Department of Biochemistry, National School of Biological Sciences, National Polytechnic Institute (IPN), Mexico City, 11340, Mexico
| | - Alfredo Santana
- Centre for Biomedical Research on Rare Disease (CIBERER), Canarias University Hospital, Institute of Biomedical Technologies, University of La Laguna, Tenerife, Spain
| | - Nicolás Villegas-Sepúlveda
- Department of Molecular Biology, Centre for Research and Advanced Studies, IPN, Mexico City, 07360, Mexico
| | | | | | | | - Carlos Wong
- Department of Biochemistry, National School of Biological Sciences, National Polytechnic Institute (IPN), Mexico City, 11340, Mexico
| | - Isabel Baeza
- Department of Biochemistry, National School of Biological Sciences, National Polytechnic Institute (IPN), Mexico City, 11340, Mexico
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Mogensen M, Skjørringe T, Kodama H, Silver K, Horn N, Møller LB. Exon duplications in the ATP7A gene: frequency and transcriptional behaviour. Orphanet J Rare Dis 2011; 6:73. [PMID: 22074552 PMCID: PMC3240829 DOI: 10.1186/1750-1172-6-73] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 11/10/2011] [Indexed: 11/19/2022] Open
Abstract
Background Menkes disease (MD) is an X-linked, fatal neurodegenerative disorder of copper metabolism, caused by mutations in the ATP7A gene. Thirty-three Menkes patients in whom no mutation had been detected with standard diagnostic tools were screened for exon duplications in the ATP7A gene. Methods The ATP7A gene was screened for exon duplications using multiplex ligation-dependent probe amplification (MLPA). The expression level of ATP7A was investigated by real-time PCR and detailed analysis of the ATP7A mRNA was performed by RT-PCR followed by sequencing. In order to investigate whether the identified duplicated fragments originated from a single or from two different X-chromosomes, polymorphic markers located in the duplicated fragments were analyzed. Results Partial ATP7A gene duplication was identified in 20 unrelated patients including one patient with Occipital Horn Syndrome (OHS). Duplications in the ATP7A gene are estimated from our material to be the disease causing mutation in 4% of the Menkes disease patients. The duplicated regions consist of between 2 and 15 exons. In at least one of the cases, the duplication was due to an intra-chromosomal event. Characterization of the ATP7A mRNA transcripts in 11 patients revealed that the duplications were organized in tandem, in a head to tail direction. The reading frame was disrupted in all 11 cases. Small amounts of wild-type transcript were found in all patients as a result of exon-skipping events occurring in the duplicated regions. In the OHS patient with a duplication of exon 3 and 4, the duplicated out-of-frame transcript coexists with an almost equally represented wild-type transcript, presumably leading to the milder phenotype. Conclusions In general, patients with duplication of only 2 exons exhibit a milder phenotype as compared to patients with duplication of more than 2 exons. This study provides insight into exon duplications in the ATP7A gene.
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Affiliation(s)
- Mie Mogensen
- Center for Applied Human Molecular Genetics, Kennedy Center, Gl, Landevej 7, 2600 Glostrup Denmark
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Abstract
This Review summarizes recent advances in understanding copper-transporting ATPase 1 (ATP7A), and examines the neurological phenotypes associated with dysfunction of this protein. Involvement of ATP7A in axonal outgrowth, synapse integrity and neuronal activation underscores the fundamental importance of copper metabolism to neurological function. Defects in ATP7A cause Menkes disease, an infantile-onset, lethal condition. Neonatal diagnosis and early treatment with copper injections enhance survival in patients with this disease, and can normalize clinical outcomes if mutant ATP7A molecules retain small amounts of residual activity. Gene replacement rescues a mouse model of Menkes disease, suggesting a potential therapeutic approach for patients with complete loss-of-function ATP7A mutations. Remarkably, a newly discovered ATP7A disorder-isolated distal motor neuropathy-has none of the characteristic clinical or biochemical abnormalities of Menkes disease or its milder allelic variant occipital horn syndrome (OHS), instead resembling Charcot-Marie-Tooth disease type 2. These findings indicate that ATP7A has a crucial but previously unappreciated role in motor neuron maintenance, and that the mechanism underlying ATP7A-related distal motor neuropathy is distinct from Menkes disease and OHS pathophysiology. Collectively, these insights refine our knowledge of the neurology of ATP7A-related copper transport diseases and pave the way for further progress in understanding ATP7A function.
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Tümer Z, Klomp L. Clinical utility gene card for: Menkes disease. Eur J Hum Genet 2011; 19:ejhg201156. [PMID: 21487442 DOI: 10.1038/ejhg.2011.56] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Zeynep Tümer
- Center for Applied Human Molecular Genetics, Kennedy Center, Glostrup, Denmark.
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