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Nava E, Hartmann B, Boxheimer L, Capone Mori A, Nuoffer JM, Sargsyan Y, Thoms S, Rosewich H, Boltshauser E. How to Detect Isolated PEX10-Related Cerebellar Ataxia? Neuropediatrics 2022; 53:159-166. [PMID: 35038753 DOI: 10.1055/s-0041-1741383] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A 4-year-old boy presented with subacute onset of cerebellar ataxia. Neuroimaging revealed cerebellar atrophy. Metabolic screening tests aiming to detect potentially treatable ataxias showed an increased value (fourfold upper limit of normal) for phytanic acid and elevated very-long-chain fatty acid (VLCFA) ratios (C24:0/C22:0 and C26:0/C22:0), while absolute concentrations of VLCFA were normal. Genetic analysis identified biallelic variants in PEX10. Immunohistochemistry confirmed pathogenicity in the patients' cultured fibroblasts demonstrating peroxisomal mosaicism with a general catalase import deficiency as well as conspicuous peroxisome morphology as an expression of impaired peroxisomal function. We describe for the first time an elongated peroxisome morphology in a patient with PEX10-related cerebellar ataxia.A literature search yielded 14 similar patients from nine families with PEX10-related cerebellar ataxia, most of them presenting their first symptoms between 3 and 8 years of age. In 11/14 patients, the first and main symptom was cerebellar ataxia; in three patients, it was sensorineural hearing impairment. Finally, all 14 patients developed ataxia. Polyneuropathy (9/14) and cognitive impairment (9/14) were common associated findings. In 12/13 patients brain MRI showed cerebellar atrophy. Phytanic acid was elevated in 8/12 patients, while absolute concentrations of VLCFA levels were in normal limits in several patients. VLCFA ratios (C24:0/C22:0 and/or C26:0/C22:0), though, were elevated in 11/11 cases. We suggest including measurement of phytanic acid and VLCFA ratios in metabolic screening tests in unexplained autosomal recessive ataxias with cerebellar atrophy, especially when there is an early onset and symptoms are mild.
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Affiliation(s)
- Esmeralda Nava
- Department of Pediatric Neurology, Cantonal Hospital Aarau, Aarau, Switzerland
| | - Britta Hartmann
- Department of Medical Genetics, Cantonal Hospital Aarau, Institute of Laboratory Medicine, Aarau, Switzerland
| | - Larissa Boxheimer
- Department of Neuroradiology, Cantonal Hospital Aarau, Aarau, Switzerland
| | - Andrea Capone Mori
- Department of Pediatric Neurology, Cantonal Hospital Aarau, Aarau, Switzerland
| | - Jean-Marc Nuoffer
- University Institute of Clinical Chemistry, Bern University Hospital, Bern, Switzerland.,University Children's Hospital Pediatric Endocrinology, Diabetology and Metabolism, Bern, Switzerland
| | - Yelena Sargsyan
- Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Göttingen, Germany
| | - Sven Thoms
- Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Göttingen, Germany.,Department of Biochemistry and Molecular Medicine, Medical School, Bielefeld University, Bielefeld, Germany
| | - Hendrik Rosewich
- Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Göttingen, Germany
| | - Eugen Boltshauser
- Department of Pediatric Neurology (emeritus), University Children's Hospital Zürich, Zürich, Switzerland
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2
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Nuebel E, Morgan JT, Fogarty S, Winter JM, Lettlova S, Berg JA, Chen YC, Kidwell CU, Maschek JA, Clowers KJ, Argyriou C, Chen L, Wittig I, Cox JE, Roh-Johnson M, Braverman N, Bonkowsky J, Gygi SP, Rutter J. The biochemical basis of mitochondrial dysfunction in Zellweger Spectrum Disorder. EMBO Rep 2021; 22:e51991. [PMID: 34351705 DOI: 10.15252/embr.202051991] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 06/21/2021] [Accepted: 07/12/2021] [Indexed: 01/09/2023] Open
Abstract
Peroxisomal biogenesis disorders (PBDs) are genetic disorders of peroxisome biogenesis and metabolism that are characterized by profound developmental and neurological phenotypes. The most severe class of PBDs-Zellweger spectrum disorder (ZSD)-is caused by mutations in peroxin genes that result in both non-functional peroxisomes and mitochondrial dysfunction. It is unclear, however, how defective peroxisomes contribute to mitochondrial impairment. In order to understand the molecular basis of this inter-organellar relationship, we investigated the fate of peroxisomal mRNAs and proteins in ZSD model systems. We found that peroxins were still expressed and a subset of them accumulated on the mitochondrial membrane, which resulted in gross mitochondrial abnormalities and impaired mitochondrial metabolic function. We showed that overexpression of ATAD1, a mitochondrial quality control factor, was sufficient to rescue several aspects of mitochondrial function in human ZSD fibroblasts. Together, these data suggest that aberrant peroxisomal protein localization is necessary and sufficient for the devastating mitochondrial morphological and metabolic phenotypes in ZSDs.
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Affiliation(s)
- Esther Nuebel
- Howard Hughes Medical Institute, Salt Lake City, UT, USA.,Department of Biochemistry, University of Utah, Salt Lake City, UT, USA.,Department of Biomedical Sciences, Noorda College of Osteopathic Medicine, Provo, USA
| | - Jeffrey T Morgan
- Howard Hughes Medical Institute, Salt Lake City, UT, USA.,Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Sarah Fogarty
- Howard Hughes Medical Institute, Salt Lake City, UT, USA.,Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Jacob M Winter
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Sandra Lettlova
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Jordan A Berg
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Yu-Chan Chen
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Chelsea U Kidwell
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - J Alan Maschek
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA.,Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA.,Metabolomics, Proteomics and Mass Spectrometry Core Research Facilities, University of Utah, Salt Lake City, UT, USA
| | - Katie J Clowers
- Department of Cell Biology, Harvard University School of Medicine, Boston, MA, USA
| | | | - Lingxiao Chen
- Department of Pathology, McGill University, Montreal, ON, Canada
| | - Ilka Wittig
- Functional Proteomics, Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
| | - James E Cox
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA.,Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA.,Metabolomics, Proteomics and Mass Spectrometry Core Research Facilities, University of Utah, Salt Lake City, UT, USA
| | - Minna Roh-Johnson
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Nancy Braverman
- Department of Human Genetics, McGill University, Montreal, ON, Canada.,Department of Pediatrics, Research Institute of the McGill University Health Centre, Montreal, ON, Canada
| | - Joshua Bonkowsky
- Primary Children's Hospital, University of Utah, Salt Lake City, UT, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard University School of Medicine, Boston, MA, USA
| | - Jared Rutter
- Howard Hughes Medical Institute, Salt Lake City, UT, USA.,Department of Biochemistry, University of Utah, Salt Lake City, UT, USA.,Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
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3
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Bose M, Cuthbertson DD, Fraser MA, Roullet JB, Gibson KM, Schules DR, Gawron KM, Gamble MB, Sacra KM, Lopez MJ, Rizzo WB. Zellweger spectrum disorder: A cross-sectional study of symptom prevalence using input from family caregivers. Mol Genet Metab Rep 2020; 25:100694. [PMID: 33335840 PMCID: PMC7733019 DOI: 10.1016/j.ymgmr.2020.100694] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 11/28/2020] [Indexed: 11/15/2022] Open
Abstract
Zellweger spectrum disorders (ZSD) are rare, debilitating genetic diseases of peroxisome biogenesis that affect multiple organ systems and present with broad clinical heterogeneity. Although many case studies have characterized the multitude of signs and symptoms associated with ZSD, there are few reports on the prevalence of symptoms to help inform the development of meaningful endpoints for future clinical trials in ZSD. In the present study, we used an online survey tool completed by family caregivers to study the occurrence, frequency and severity of symptoms in individuals diagnosed with ZSD. Responses from caregivers representing 54 living and 25 deceased individuals with ZSD were collected over an 8-month period. Both perception of disease severity and prevalence of various symptoms were greater in responses from family caregivers of deceased individuals compared to those of living individuals with ZSD. Compared with previous reports for ZSD, the combined prevalence of seizures (53%) and adrenal insufficiency (45%) were nearly twice as high. Overall, this community-engaged approach to rare disease data collection is the largest study reporting on the prevalence of symptoms in ZSD, and our findings suggest that previous reports may be underreporting the true prevalence of several symptoms in ZSD. Studies such as this used in conjunction with clinician- led reports may be useful for informing the design of future clinical trials addressing ZSD. Zellweger spectrum disorders (ZSD) are rare, genetic multi-system disorders. There are few reports on symptom prevalence in ZSD. We present the largest caregiver-reported study to date on ZSD symptom prevalence. This study will help develop appropriate outcomes for clinical trials in ZSD.
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Affiliation(s)
- Mousumi Bose
- Department of Nutrition and Food Stsudies, Montclair State University, 1 Normal Avenue, UN 2159, Montclair, NJ 07043, USA
| | - David D Cuthbertson
- Department of Health Informatics Institute, College of Medicine Pediatrics, University of South Florida, 4202 E Fowler Ave, Tampa, FL 33620, USA
| | - Marsha A Fraser
- Department of Health Informatics Institute, College of Medicine Pediatrics, University of South Florida, 4202 E Fowler Ave, Tampa, FL 33620, USA
| | - Jean-Baptiste Roullet
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, 412 E. Spokane Falls Blvd, Spokane, WA 99210, USA
| | - K Michael Gibson
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, 412 E. Spokane Falls Blvd, Spokane, WA 99210, USA
| | - Dana R Schules
- Department of Nutrition and Food Stsudies, Montclair State University, 1 Normal Avenue, UN 2159, Montclair, NJ 07043, USA
| | - Kelly M Gawron
- Department of Nutrition and Food Stsudies, Montclair State University, 1 Normal Avenue, UN 2159, Montclair, NJ 07043, USA
| | - Melissa B Gamble
- Global Foundation for Peroxisomal Disorders, P.O. Box 33238, Tulsa, OK 74153, USA
| | - Kathryn M Sacra
- Global Foundation for Peroxisomal Disorders, P.O. Box 33238, Tulsa, OK 74153, USA
| | - Melisa J Lopez
- Global Foundation for Peroxisomal Disorders, P.O. Box 33238, Tulsa, OK 74153, USA
| | - William B Rizzo
- Department of Pediatrics, University of Nebraska Medical Center University of Nebraska, 985940 Nebraska Medical Center - DRC II 4064, Omaha, NE 68198-5940, USA
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4
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Honsho M, Okumoto K, Tamura S, Fujiki Y. Peroxisome Biogenesis Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1299:45-54. [PMID: 33417206 DOI: 10.1007/978-3-030-60204-8_4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Peroxisomes are presented in all eukaryotic cells and play essential roles in many of lipid metabolic pathways, including β-oxidation of fatty acids and synthesis of ether-linked glycerophospholipids, such as plasmalogens. Impaired peroxisome biogenesis, including defects of membrane assembly, import of peroxisomal matrix proteins, and division of peroxisome, causes peroxisome biogenesis disorders (PBDs). Fourteen complementation groups of PBDs are found, and their complementing genes termed PEXs are isolated. Several new mutations in peroxins from patients with mild PBD phenotype or patients with phenotypes unrelated to the commonly observed impairments of PBD patients are found by next-generation sequencing. Exploring a dysfunctional step(s) caused by the mutation is important for unveiling the pathogenesis of novel mutation by means of cellular and biochemical analyses.
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Affiliation(s)
| | - Kanji Okumoto
- Department of Biology, Faculty of Sciences, Kyushu University Graduate School, Fukuoka, Japan
| | | | - Yukio Fujiki
- Institute of Rheological Functions of Food, Fukuoka, Japan. .,Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
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5
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Bellettato CM, Hubert L, Scarpa M, Wangler MF. Inborn Errors of Metabolism Involving Complex Molecules: Lysosomal and Peroxisomal Storage Diseases. Pediatr Clin North Am 2018; 65:353-373. [PMID: 29502918 DOI: 10.1016/j.pcl.2017.11.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Peroxisomes and lysosomes are distinct subcellular compartments that underlie several pediatric metabolic disorders. Knowledge of their function and cell biology leads to understanding how the disorders result from genetic defects. Diagnostic and therapeutic approaches for the disorders take advantage of the cell biology mechanisms. Whereas peroxisomal disorders are characterized by enzymatic defects in peroxisomal pathways leading to metabolic and lipid changes, lysosomal storage disorders are marked by accumulation of substrates of lysosomal pathways inside the lysosome. The human diseases related to these two organelles are reviewed, focusing on general disease patterns and underlying diagnosis and treatment principles.
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Affiliation(s)
- Cinzia Maria Bellettato
- Brains for Brains Foundation, Department of Women and Children Health, Via Giustiniani 3, Padova 35128, Italy
| | - Leroy Hubert
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Maurizio Scarpa
- Brains for Brains Foundation, Department of Women and Children Health, Via Giustiniani 3, Padova 35128, Italy; Center for Rare Diseases, Department of Pediatric and Adolescent Medicine, Helios Dr. Horst Schmidt Klinik, Ludwig-Erhard-Straße 100, Wiesbaden 65199, Germany; Department of Women and Children Health, University of Padova, Via Giustiniani 3, Padova 35128, Italy
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA.
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6
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Lin JP, Mironova YA, Shrager P, Giger RJ. LRP1 regulates peroxisome biogenesis and cholesterol homeostasis in oligodendrocytes and is required for proper CNS myelin development and repair. eLife 2017; 6:30498. [PMID: 29251594 PMCID: PMC5752207 DOI: 10.7554/elife.30498] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 12/15/2017] [Indexed: 01/01/2023] Open
Abstract
Low-density lipoprotein receptor-related protein-1 (LRP1) is a large endocytic and signaling molecule broadly expressed by neurons and glia. In adult mice, global inducible (Lrp1flox/flox;CAG-CreER) or oligodendrocyte (OL)-lineage specific ablation (Lrp1flox/flox;Pdgfra-CreER) of Lrp1 attenuates repair of damaged white matter. In oligodendrocyte progenitor cells (OPCs), Lrp1 is required for cholesterol homeostasis and differentiation into mature OLs. Lrp1-deficient OPC/OLs show a strong increase in the sterol-regulatory element-binding protein-2 yet are unable to maintain normal cholesterol levels, suggesting more global metabolic deficits. Mechanistic studies revealed a decrease in peroxisomal biogenesis factor-2 and fewer peroxisomes in OL processes. Treatment of Lrp1−/− OPCs with cholesterol or activation of peroxisome proliferator-activated receptor-γ with pioglitazone alone is not sufficient to promote differentiation; however, when combined, cholesterol and pioglitazone enhance OPC differentiation into mature OLs. Collectively, our studies reveal a novel role for Lrp1 in peroxisome biogenesis, lipid homeostasis, and OPC differentiation during white matter development and repair.
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Affiliation(s)
- Jing-Ping Lin
- Department of Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI, United States
| | - Yevgeniya A Mironova
- Cellular and Molecular Biology Graduate Program, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Peter Shrager
- Department of Neuroscience, University of Rochester Medical Center, Rochester, NY, United States
| | - Roman J Giger
- Department of Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI, United States.,Cellular and Molecular Biology Graduate Program, University of Michigan Medical School, Ann Arbor, MI, United States.,Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, United States.,Interdepartmental Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI, United States
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7
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Fedick A, Jalas C, Treff NR. A deleterious mutation in the PEX2 gene causes Zellweger syndrome in individuals of Ashkenazi Jewish descent. Clin Genet 2013; 85:343-6. [PMID: 23590336 DOI: 10.1111/cge.12170] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 04/12/2013] [Accepted: 04/12/2013] [Indexed: 11/29/2022]
Abstract
Zellweger syndrome is known to be caused by numerous mutations that occur in at least 12 of the PEX genes. While phenotypes vary, many are severely debilitating, and death can result in affected newborns. Since the disease follows an autosomal recessive pattern of inheritance, carrier screening can be done for at-risk couples, but the number of potential mutations sites to screen can be daunting. Ethnicity-specific studies can help narrow this range by highlighting mutations that are present at higher percentages in certain populations. In this article, the carrier frequencies for two mutations causative of the severe Zellweger syndrome spectrum phenotype that occur in the PEX2 gene, c.355C>T and c.550del, were studied in individuals of Ashkenazi Jewish descent in order to advise on inclusion in existing carrier screening mutation panels for this population. The screening was performed for 2093 individuals through the use of TaqMan genotyping assays, real-time PCR, and allelic discrimination. Results indicated a carrier frequency of 0.813% (±0.385%) for the c.355C>T mutation and a carrier frequency of 0.00% (±0.00%) for the c.550del mutation. On the basis of these frequencies, we believe that the c.355C>T mutation should be considered for inclusion in carrier screening panels for the Ashkenazi population.
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Affiliation(s)
- A Fedick
- Department of Microbiology and Molecular Genetics, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ, 08854-5635, USA; Reproductive Medicine Associates of New Jersey, Basking Ridge, NJ, 07920, USA
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8
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Noguchi M, Okumoto K, Fujiki Y. System to quantify the import of peroxisomal matrix proteins by fluorescence intensity. Genes Cells 2013; 18:476-92. [PMID: 23573963 DOI: 10.1111/gtc.12051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 02/23/2013] [Indexed: 11/30/2022]
Abstract
Fourteen distinct peroxins are essential for peroxisome biogenesis in mammals, of which ten are involved in the import of matrix proteins into peroxisomes. Peroxisomal matrix protein import is regulated by various cellular factors; however, the mechanisms underlying this regulation are poorly understood. This is primarily because no quantitative detection method with high resolution is available to study the import of peroxisomal matrix proteins. Here, we developed a monitoring system that uses a fluorescent reporter that is stabilized in peroxisomes but is degraded in the cytosol. An FK506 binding protein 12 variant, termed destabilization domain (DD), is rapidly and constitutively degraded by proteasomes when expressed in mammalian cells. DD is reversibly protected by the addition of a specific synthetic ligand. In the absence of the ligand, a reporter molecule, enhanced GFP (EGFP) fused with DD and peroxisomal targeting signal 1 (DD-EGFP-PTS1), is largely degraded in the cytosol. By contrast, in the presence of the ligand, the reporter is stabilized and translocates into peroxisomes. Upon withdrawal of the ligand, the reporter in peroxisomes remains intact, whereas that in the cytosol is rapidly degraded. Thus, peroxisomal protein import can be readily quantified by measuring the fluorescence intensity of whole cells.
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Affiliation(s)
- Masafumi Noguchi
- Graduate School of Systems Life Sciences, Kyushu University Graduate School, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
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9
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Waterham HR, Ebberink MS. Genetics and molecular basis of human peroxisome biogenesis disorders. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1430-41. [PMID: 22871920 DOI: 10.1016/j.bbadis.2012.04.006] [Citation(s) in RCA: 189] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 03/30/2012] [Accepted: 04/11/2012] [Indexed: 10/28/2022]
Abstract
Human peroxisome biogenesis disorders (PBDs) are a heterogeneous group of autosomal recessive disorders comprised of two clinically distinct subtypes: the Zellweger syndrome spectrum (ZSS) disorders and rhizomelic chondrodysplasia punctata (RCDP) type 1. PBDs are caused by defects in any of at least 14 different PEX genes, which encode proteins involved in peroxisome assembly and proliferation. Thirteen of these genes are associated with ZSS disorders. The genetic heterogeneity among PBDs and the inability to predict from the biochemical and clinical phenotype of a patient with ZSS which of the currently known 13 PEX genes is defective, has fostered the development of different strategies to identify the causative gene defects. These include PEX cDNA transfection complementation assays followed by sequencing of the thus identified PEX genes, and a PEX gene screen in which the most frequently mutated exons of the different PEX genes are analyzed. The benefits of DNA testing for PBDs include carrier testing of relatives, early prenatal testing or preimplantation genetic diagnosis in families with a recurrence risk for ZSS disorders, and insight in genotype-phenotype correlations, which may eventually assist to improve patient management. In this review we describe the current status of genetic analysis and the molecular basis of PBDs.
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10
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Mignarri A, Vinciguerra C, Giorgio A, Ferdinandusse S, Waterham H, Wanders R, Bertini E, Dotti MT, Federico A. Zellweger Spectrum Disorder with Mild Phenotype Caused by PEX2 Gene Mutations. JIMD Rep 2012; 6:43-6. [PMID: 23430938 DOI: 10.1007/8904_2011_102] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 09/30/2011] [Accepted: 09/30/2011] [Indexed: 12/12/2022] Open
Abstract
The Zellweger spectrum disorders (ZSDs) are known to be severe disorders with onset in the newborn period or later in childhood, frequently resulting in death during childhood or adolescence. Here, we report a case of ZSD due to mutations in the PEX2 gene, with very mild phenotype. A 51-year-old Italian man was referred to us because of a clinical picture characterized by ataxia, areflexia, nystagmus, and strabismus, with childhood onset and slowly progressive course. The patient showed no cognitive impairment. Neurological examination revealed gait ataxia, dysarthria, dysmetria, areflexia, and bilateral pes cavus. Nerve conduction studies indicated a severe axonal sensorimotor polyneuropathy. Brain MRI showed marked cerebellar atrophy and absence of white matter involvement. MR spectroscopy uncovered a decreased N-acetyl aspartate peak. Biochemical analyses suggested a mild peroxisomal defect. Sequence analysis of the PEX2 gene identified two heterozygous mutations. The clinical phenotype of our patient differs from previously reported ZSD patients with PEX2 gene mutations and suggests that genetic screening of PEX2 is warranted in children and adults with otherwise unexplained autosomal recessive ataxia. MRI findings diverged from the "classic" spectrum observed in ZSDs. The moderate impairment in peroxisome biogenesis seems to affect predominantly neuronal cells in cerebellum, leading to cerebellar atrophy.
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Affiliation(s)
- Andrea Mignarri
- Department of Neurological, Neurosurgical and Behavioural Sciences, Medical School, University of Siena, Viale Bracci 2, Siena, 53100, Italy
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11
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Ebberink MS, Mooijer PAW, Gootjes J, Koster J, Wanders RJA, Waterham HR. Genetic classification and mutational spectrum of more than 600 patients with a Zellweger syndrome spectrum disorder. Hum Mutat 2011; 32:59-69. [PMID: 21031596 DOI: 10.1002/humu.21388] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The autosomal recessive Zellweger syndrome spectrum (ZSS) disorders comprise a main subgroup of the peroxisome biogenesis disorders and can be caused by mutations in any of 12 different currently identified PEX genes resulting in severe multisystemic disorders. To get insight into the spectrum of PEX gene defects among ZSS disorders and to investigate if additional human PEX genes are required for functional peroxisome biogenesis, we assigned over 600 ZSS fibroblast cell lines to different genetic complementation groups. These fibroblast cell lines were subjected to a complementation assay involving fusion by means of polyethylene glycol or a PEX cDNA transfection assay specifically developed for this purpose. In a majority of the cell lines we subsequently determined the underlying mutations by sequence analysis of the implicated PEX genes. The PEX cDNA transfection assay allows for the rapid identification of PEX genes defective in ZSS patients. The assignment of over 600 fibroblast cell lines to different genetic complementation groups provides the most comprehensive and representative overview of the frequency distribution of the different PEX gene defects. We did not identify any novel genetic complementation group, suggesting that all PEX gene defects resulting in peroxisome deficiency are currently known.
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Affiliation(s)
- Merel S Ebberink
- Academic Medical Centre at the University of Amsterdam, The Netherlands
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12
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Autosomal recessive cerebellar ataxia caused by mutations in the PEX2 gene. Orphanet J Rare Dis 2011; 6:8. [PMID: 21392394 PMCID: PMC3064617 DOI: 10.1186/1750-1172-6-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Accepted: 03/10/2011] [Indexed: 01/13/2023] Open
Abstract
Objective To expand the spectrum of genetic causes of autosomal recessive cerebellar ataxia (ARCA). Case report Two brothers are described who developed progressive cerebellar ataxia at 3 1/2 and 18 years, respectively. After ruling out known common genetic causes of ARCA, analysis of blood peroxisomal markers strongly suggested a peroxisomal biogenesis disorder. Sequencing of candidate PEX genes revealed a homozygous c.865_866insA mutation in the PEX2 gene leading to a frameshift 17 codons upstream of the stop codon. PEX gene mutations usually result in a severe neurological phenotype (Zellweger spectrum disorders). Conclusions Genetic screening of PEX2 and other PEX genes involved in peroxisomal biogenesis is warranted in children and adults with ARCA.
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13
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Steinberg SJ, Dodt G, Raymond GV, Braverman NE, Moser AB, Moser HW. Peroxisome biogenesis disorders. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1733-48. [PMID: 17055079 DOI: 10.1016/j.bbamcr.2006.09.010] [Citation(s) in RCA: 338] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Revised: 09/05/2006] [Accepted: 09/06/2006] [Indexed: 01/02/2023]
Abstract
Defects in PEX genes impair peroxisome assembly and multiple metabolic pathways confined to this organelle, thus providing the biochemical and molecular bases of the peroxisome biogenesis disorders (PBD). PBD are divided into two types--Zellweger syndrome spectrum (ZSS) and rhizomelic chondrodysplasia punctata (RCDP). Biochemical studies performed in blood and urine are used to screen for the PBD. DNA testing is possible for all of the disorders, but is more challenging for the ZSS since 12 PEX genes are known to be associated with this spectrum of PBD. In contrast, PBD-RCDP is associated with defects in the PEX7 gene alone. Studies of the cellular and molecular defects in PBD patients have contributed significantly to our understanding of the role of each PEX gene in peroxisome assembly.
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Affiliation(s)
- Steven J Steinberg
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Steinberg S, Chen L, Wei L, Moser A, Moser H, Cutting G, Braverman N. The PEX Gene Screen: molecular diagnosis of peroxisome biogenesis disorders in the Zellweger syndrome spectrum. Mol Genet Metab 2004; 83:252-63. [PMID: 15542397 DOI: 10.1016/j.ymgme.2004.08.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2004] [Revised: 08/14/2004] [Accepted: 08/20/2004] [Indexed: 10/26/2022]
Abstract
Peroxisome biogenesis disorders in the Zellweger syndrome spectrum (PBD-ZSS) are caused by defects in at least 12 PEX genes required for normal organelle assembly. Clinical and biochemical features continue to be used reliably to assign patients to this general disease category. Identification of the precise genetic defect is important, however, to permit carrier testing and early prenatal diagnosis. Molecular analysis is likely to expand the clinical spectrum of PBD and may also provide data relevant to prognosis and future therapeutic intervention. However, the large number of genes involved has thus far impeded rapid mutation identification. In response, we developed the PEX Gene Screen, an algorithm for the systematic screening of exons in the six PEX genes most commonly defective in PBD-ZSS. We used PCR amplification of genomic DNA and sequencing to screen 91 unclassified PBD-ZSS patients for mutations in PEX1, PEX26, PEX6, PEX12, PEX10, and PEX2. A maximum of 14 reactions per patient identified pathological mutations in 79% and both mutant alleles in 54%. Twenty-five novel mutations were identified overall. The proportion of patients with different PEX gene defects correlated with frequencies previously identified by complementation analysis. This systematic, hierarchical approach to mutation identification is therefore a valuable tool to identify rapidly the molecular etiology of suspected PBD-ZSS disorders.
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Affiliation(s)
- Steven Steinberg
- Peroxisomal Diseases Laboratory, Kennedy Krieger Institute and Department of Neurology, Johns Hopkins University, Baltimore, MD, USA.
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