1
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Alzahem TA, AlTheeb A, Ba-Abbad R. PRPS1-associated retinopathy: a diagnostic odyssey. Ophthalmic Genet 2024:1-5. [PMID: 38619019 DOI: 10.1080/13816810.2024.2321871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/18/2024] [Indexed: 04/16/2024]
Abstract
PURPOSE This study describes how the diagnosis of Usher syndrome was revised to PRPS1-associated retinopathy and Charcot-Marie-Tooth disease type 5. CASE REPORT A 38-year-old female with bilaterally subnormal vision and non-congenital hearing loss was initially diagnosed with Usher syndrome, based on finding variants in three genes (MYO7A, USH2A, and PCDH15), was re-evaluated at the inherited retinal disorders clinic. She had asymmetric retinopathy and right macular pseudocoloboma. She was also found to have myopathic facies, poor grip strength and atrophy of the calf muscles. Whole exome sequencing including variants in PRPS1 showed a variant (NM_002764.4:c.287 G > A; p.Arg96Gln), which was not detected by targeted Sanger sequencing of the DNA from her mother and sister. CONCLUSION The constellation of asymmetric retinopathy and non-congenital hearing impairment should prompt the clinician to search for other diagnoses that may not be covered by an Usher syndrome next generation sequencing panel. Interpretation of genetic testing results should be correlated with a detailed clinical phenotype.
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Affiliation(s)
- Tariq A Alzahem
- Ocular Genetics Service, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
- Ophthalmology Department, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Abdulwahab AlTheeb
- Ocular Genetics Service, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Rola Ba-Abbad
- Ocular Genetics Service, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
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2
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Štajer K, Kovač N, Šikonja J, Mlinarič M, Bertok S, Brecelj J, Debeljak M, Kovač J, Markelj G, Neubauer D, Rus R, Žerjav Tanšek M, Drole Torkar A, Zver A, Battelino T, Jiménez Torres R, Grošelj U. Clinical and genetic characteristics of a patient with phosphoribosyl pyrophosphate synthetase 1 deficiency and a systematic literature review. Mol Genet Metab Rep 2023; 36:100986. [PMID: 37670898 PMCID: PMC10475845 DOI: 10.1016/j.ymgmr.2023.100986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 09/07/2023] Open
Abstract
Phosphoribosylpyrophosphate synthetase 1 (PRS-I) is an enzyme involved in nucleotide metabolism. Pathogenic variants in the PRPS1 are rare and PRS-I deficiency can manifest as three clinical syndromes: X-linked non-syndromic sensorineural deafness (DFN2), X-linked Charcot-Marie-Tooth neuropathy type 5 (CMTX5) and Arts syndrome. We present a Slovenian patient with PRS-I enzyme deficiency due to a novel pathogenic variant - c.424G > A (p.Val142Ile) in the PRPS1 gene, who presented with gross motor impairment, severe sensorineural deafness, balance issues, ataxia, and frequent respiratory infections. In addition, we report the findings of a systemic literature review of all described male cases of Arts syndrome and CMTX5 as well as intermediate phenotypes. As already proposed by other authors, our results confirm PRS-I deficiency should be viewed as a phenotypic continuum rather than three separate syndromes because there are multiple reports of patients with an intermediary clinical presentation.
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Affiliation(s)
- Katarina Štajer
- Department of Endocrinology, Diabetes, and Metabolic Diseases, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Neja Kovač
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Jaka Šikonja
- Department of Endocrinology, Diabetes, and Metabolic Diseases, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Matej Mlinarič
- Department of Endocrinology, Diabetes, and Metabolic Diseases, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Sara Bertok
- Department of Endocrinology, Diabetes, and Metabolic Diseases, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Jernej Brecelj
- Department of Gastroenterology, Hepatology and Nutrition, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Maruša Debeljak
- Laboratory of Genetics, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Jernej Kovač
- Laboratory of Genetics, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Gašper Markelj
- Department of Allergology, Rheumatology and Clinical Immunology, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - David Neubauer
- Department of Child, Adolescent and Developmental Neurologyx, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Rina Rus
- Department of Nephrology, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Mojca Žerjav Tanšek
- Department of Endocrinology, Diabetes, and Metabolic Diseases, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Ana Drole Torkar
- Department of Endocrinology, Diabetes, and Metabolic Diseases, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Aleksandra Zver
- Unit for Pulmonary Diseases, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Tadej Battelino
- Department of Endocrinology, Diabetes, and Metabolic Diseases, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Rosa Jiménez Torres
- La Paz University Hospital Health Research Institute (FIBHULP), IdiPaz, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Spain
| | - Urh Grošelj
- Department of Endocrinology, Diabetes, and Metabolic Diseases, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
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3
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Hvorecny KL, Hargett K, Quispe JD, Kollman JM. Human PRPS1 filaments stabilize allosteric sites to regulate activity. Nat Struct Mol Biol 2023; 30:391-402. [PMID: 36747094 PMCID: PMC10033377 DOI: 10.1038/s41594-023-00921-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 01/10/2023] [Indexed: 02/08/2023]
Abstract
The universally conserved enzyme phosphoribosyl pyrophosphate synthetase (PRPS) assembles filaments in evolutionarily diverse organisms. PRPS is a key regulator of nucleotide metabolism, and mutations in the human enzyme PRPS1 lead to a spectrum of diseases. Here we determine structures of human PRPS1 filaments in active and inhibited states, with fixed assembly contacts accommodating both conformations. The conserved assembly interface stabilizes the binding site for the essential activator phosphate, increasing activity in the filament. Some disease mutations alter assembly, supporting the link between filament stability and activity. Structures of active PRPS1 filaments turning over substrate also reveal coupling of catalysis in one active site with product release in an adjacent site. PRPS1 filaments therefore provide an additional layer of allosteric control, conserved throughout evolution, with likely impact on metabolic homeostasis. Stabilization of allosteric binding sites by polymerization adds to the growing diversity of assembly-based enzyme regulatory mechanisms.
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Affiliation(s)
- Kelli L Hvorecny
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Kenzee Hargett
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Joel D Quispe
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Justin M Kollman
- Department of Biochemistry, University of Washington, Seattle, WA, USA.
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4
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Sharma N, Kumari D, Panigrahi I, Khetarpal P. A systematic review of the monogenic causes of Non-Syndromic Hearing Loss (NSHL) and discussion of Current Diagnosis and Treatment options. Clin Genet 2023; 103:16-34. [PMID: 36089522 DOI: 10.1111/cge.14228] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 09/02/2022] [Accepted: 09/06/2022] [Indexed: 12/13/2022]
Abstract
Hearing impairment is one of the most widespread inheritable sensory disorder affecting at least 1 in every 1000 born. About two-third of hereditary hearing loss (HHL) disorders are non-syndromic. To provide comprehensive update of monogenic causes of non-syndromic hearing loss (NSHL), literature search has been carried out with appropriate keywords in the following databases-PubMed, Google Scholar, Cochrane library, and Science Direct. Out of 2214 papers, 271 papers were shortlisted after applying inclusion and exclusion criterion. Data extracted from selected papers include information about gene name, identified pathogenic variants, ethnicity of the patient, age of onset, gender, title, authors' name, and year of publication. Overall, pathogenic variants in 98 different genes have been associated with NSHL. These genes have important role to play during early embryonic development in ear structure formation and hearing development. Here, we also review briefly the recent information about diagnosis and treatment approaches. Understanding pathogenic genetic variants are helpful in the management of affected and may offer targeted therapies in future.
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Affiliation(s)
- Nandita Sharma
- Department of Human Genetics and Molecular Medicine, School of Health Sciences, Central University of Punjab, Bathinda, India
| | - Divya Kumari
- Department of Pediatrics Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Inusha Panigrahi
- Department of Pediatrics Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Preeti Khetarpal
- Department of Human Genetics and Molecular Medicine, School of Health Sciences, Central University of Punjab, Bathinda, India
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5
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Ugbogu EA, Schweizer LM, Schweizer M. Contribution of Model Organisms to Investigating the Far-Reaching Consequences of PRPP Metabolism on Human Health and Well-Being. Cells 2022; 11:1909. [PMID: 35741038 PMCID: PMC9221600 DOI: 10.3390/cells11121909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/03/2022] [Accepted: 05/05/2022] [Indexed: 11/17/2022] Open
Abstract
Phosphoribosyl pyrophosphate synthetase (PRS EC 2.7.6.1) is a rate-limiting enzyme that irreversibly catalyzes the formation of phosphoribosyl pyrophosphate (PRPP) from ribose-5-phosphate and adenosine triphosphate (ATP). This key metabolite is required for the synthesis of purine and pyrimidine nucleotides, the two aromatic amino acids histidine and tryptophan, the cofactors nicotinamide adenine dinucleotide (NAD+) and nicotinamide adenine dinucleotide phosphate (NADP+), all of which are essential for various life processes. Despite its ubiquity and essential nature across the plant and animal kingdoms, PRPP synthetase displays species-specific characteristics regarding the number of gene copies and architecture permitting interaction with other areas of cellular metabolism. The impact of mutated PRS genes in the model eukaryote Saccharomyces cerevisiae on cell signalling and metabolism may be relevant to the human neuropathies associated with PRPS mutations. Human PRPS1 and PRPS2 gene products are implicated in drug resistance associated with recurrent acute lymphoblastic leukaemia and progression of colorectal cancer and hepatocellular carcinoma. The investigation of PRPP metabolism in accepted model organisms, e.g., yeast and zebrafish, has the potential to reveal novel drug targets for treating at least some of the diseases, often characterized by overlapping symptoms, such as Arts syndrome and respiratory infections, and uncover the significance and relevance of human PRPS in disease diagnosis, management, and treatment.
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Affiliation(s)
- Eziuche A. Ugbogu
- School of Life Sciences, Heriot Watt University, Edinburgh EH14 4AS, UK; (E.A.U.); (L.M.S.)
| | - Lilian M. Schweizer
- School of Life Sciences, Heriot Watt University, Edinburgh EH14 4AS, UK; (E.A.U.); (L.M.S.)
| | - Michael Schweizer
- Institute of Biological Chemistry, Biophysics & Engineering (IB3), School of Engineering &Physical Sciences, Heriot Watt University, Edinburgh EH14 4AS, UK
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6
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Shirakawa S, Murakami T, Hashiguchi A, Takashima H, Hasegawa H, Ichida K, Sunada Y. A Novel PRPS1 Mutation in a Japanese Patient with CMTX5. Intern Med 2022; 61:1749-1751. [PMID: 34803094 PMCID: PMC9259300 DOI: 10.2169/internalmedicine.8029-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The PRPS1 gene encodes phosphoribosyl pyrophosphate synthetase 1 (PRS-1). The phenotypes associated with PRPS1 mutations include DFN2 (mild PRS-1 deficiency), X-linked Charcot-Marie-Tooth disease type 5 (CMTX5) (moderate PRS-1 deficiency), Arts syndrome (severe PRS-1 deficiency), and PRS-1 superactivity1. CMTX5 is a very rare hereditary neuropathy characterized by deafness, optic atrophy, and polyneuropathy. We herein report a Japanese patient with CMTX5 who had a novel hemizygous mutation c.82 G>C in PRPS1. Despite showing a typical clinical picture, the decrease in enzyme activity measured in the patient's erythrocytes was milder than in previously reported cases.
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Affiliation(s)
| | | | - Akihiro Hashiguchi
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Japan
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Japan
| | - Hiroshi Hasegawa
- Department of Pathophysiology, Tokyo University of Pharmacy and Life Sciences, School of Pharmacy, Japan
| | - Kimiyoshi Ichida
- Department of Pathophysiology, Tokyo University of Pharmacy and Life Sciences, School of Pharmacy, Japan
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7
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Puusepp S, Reinson K, Pajusalu S, van Kuilenburg ABP, Dobritzsch D, Roelofsen J, Stenzel W, Õunap K. Atypical presentation of Arts syndrome due to a novel hemizygous loss-of-function variant in the PRPS1 gene. Mol Genet Metab Rep 2020; 25:100677. [PMID: 33294372 PMCID: PMC7689168 DOI: 10.1016/j.ymgmr.2020.100677] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/06/2020] [Accepted: 11/07/2020] [Indexed: 11/30/2022] Open
Abstract
The PRPS1 gene, located on Xq22.3, encodes phosphoribosyl-pyrophosphate synthetase (PRPS), a key enzyme in de novo purine synthesis. Three clinical phenotypes are associated with loss-of-function PRPS1 variants and decreased PRPS activity: Arts syndrome (OMIM: 301835), Charcot–Marie–Tooth disease type 5 (CMTX5, OMIM: 311070), and nonsyndromic X-linked deafness (DFN2, OMIM: 304500). Hearing loss is present in all cases. CMTX5 patients also show peripheral neuropathy and optic atrophy. Arts syndrome includes developmental delay, intellectual disability, ataxia, and susceptibility to infections, in addition to the above three features. Gain-of-function PRPS1 variants result in PRPS superactivity (OMIM: 300661) with hyperuricemia and gout. We report a 6-year-old boy who presented with marked generalized muscular hypotonia, global developmental delay, lack of speech, trunk instability, exercise intolerance, hypomimic face with open mouth, oropharyngeal dysphagia, dysarthria, and frequent upper respiratory tract infections. However, his nerve conduction velocity, audiologic, and funduscopic investigations were normal. A novel hemizygous variant, c.130A > G p.(Ile44Val), was found in the PRPS1 gene by panel sequencing. PRPS activity in erythrocytes was markedly reduced, confirming the pathogenicity of the variant. Serum uric acid and urinary purine and pyrimidine metabolite levels were normal. In conclusion, we present a novel PRPS1 loss-of-function variant in a patient with some clinical features of Arts syndrome, but lacking a major attribute, hearing loss, which is congenital/early-onset in all other reported Arts syndrome patients. In addition, it is important to acknowledge that normal levels of serum and urinary purine and pyrimidine metabolites do not exclude PRPS1-related disorders. We describe a male patient with atypical presentation of Arts syndrome. Our patient harbors a novel loss-of-function variant in the PRPS1 gene. The purine and pyrimidine levels can be normal in patients with decreased PRPS activity.
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Affiliation(s)
- Sanna Puusepp
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia.,Department of Clinical Genetics, Institute of Clinical Medicine, Faculty of Medicine, University of Tartu, Tartu, Estonia
| | - Karit Reinson
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia.,Department of Clinical Genetics, Institute of Clinical Medicine, Faculty of Medicine, University of Tartu, Tartu, Estonia
| | - Sander Pajusalu
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia.,Department of Clinical Genetics, Institute of Clinical Medicine, Faculty of Medicine, University of Tartu, Tartu, Estonia.,Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - André B P van Kuilenburg
- Department of Clinical Chemistry, Cancer Center Amsterdam, Amsterdam Gastroenterology & Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | | | - Jeroen Roelofsen
- Department of Clinical Chemistry, Cancer Center Amsterdam, Amsterdam Gastroenterology & Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Werner Stenzel
- Department of Neuropathology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Leibniz Science Campus Chronic Inflammation, Berlin, Germany
| | - Katrin Õunap
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia.,Department of Clinical Genetics, Institute of Clinical Medicine, Faculty of Medicine, University of Tartu, Tartu, Estonia
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8
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PRPS1 loss-of-function variants, from isolated hearing loss to severe congenital encephalopathy: New cases and literature review. Eur J Med Genet 2020; 63:104033. [PMID: 32781272 DOI: 10.1016/j.ejmg.2020.104033] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/18/2020] [Accepted: 07/31/2020] [Indexed: 11/21/2022]
Abstract
We describe two sporadic and two familial cases with loss-of-function variants in PRPS1, which is located on the X chromosome and encodes phosphoribosyl pyrophosphate synthetase 1 (PRS-1). We illustrate the clinical variability associated with decreased PRS-1 activity, ranging from mild isolated hearing loss to severe encephalopathy. One of the variants we identified has already been reported with a phenotype similar to our patient's, whereas the other three were unknown. The clinical and biochemical information we provide will hopefully contribute to gain insight into the correlation between genotype and phenotype of this rare condition, both in females and in males. Moreover, our observation of a new family in which hemizygous males display hearing loss without any neurological or ophthalmological symptoms prompts us to suggest analysing PRPS1 in cases of isolated hearing loss. Eventually, PRPS1 variants should be considered as a differential diagnosis of mitochondrial disorders.
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9
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PRPS-Associated Disorders and the Drosophila Model of Arts Syndrome. Int J Mol Sci 2020; 21:ijms21144824. [PMID: 32650483 PMCID: PMC7403961 DOI: 10.3390/ijms21144824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/05/2020] [Accepted: 07/05/2020] [Indexed: 11/18/2022] Open
Abstract
While a plethora of genetic techniques have been developed over the past century, modifying specific sequences of the fruit fly genome has been a difficult, if not impossible task. clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 truly redefined molecular genetics and provided new tools to model human diseases in Drosophila melanogaster. This is particularly true for genes whose protein sequences are highly conserved. Phosphoribosyl pyrophosphate synthetase (PRPS) is a rate-limiting enzyme in nucleotide metabolism whose missense mutations are found in several neurological disorders, including Arts syndrome. In addition, PRPS is deregulated in cancer, particularly those that become resistant to cancer therapy. Notably, DrosophilaPRPS shares about 90% protein sequence identity with its human orthologs, making it an ideal gene to study via CRISPR/Cas9. In this review, we will summarize recent findings on PRPS mutations in human diseases including cancer and on the molecular mechanisms by which PRPS activity is regulated. We will also discuss potential applications of Drosophila CRISPR/Cas9 to model PRPS-dependent disorders and other metabolic diseases that are associated with nucleotide metabolism.
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10
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Lerat J, Magdelaine C, Derouault P, Beauvais-Dzugan H, Bieth E, Acket B, Arne-Bes MC, Sturtz F, Lia AS. New PRPS1 variant p.(Met68Leu) located in the dimerization area identified in a French CMTX5 patient. Mol Genet Genomic Med 2019; 7:e875. [PMID: 31338985 PMCID: PMC6732271 DOI: 10.1002/mgg3.875] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 05/21/2019] [Accepted: 07/08/2019] [Indexed: 12/04/2022] Open
Abstract
Background CMTX5 is characterized by peripheral neuropathy, early‐onset sensorineural hearing impairment, and optic neuropathy. Only seven variants have been reported and no genotype‐phenotype correlations have yet been established. PRPS1 has a crystallographic structure, as it is composed of three dimers that constitute a hexamer. Methods Next‐generation sequencing (NGS) was performed using a custom 92‐gene panel designed for the diagnosis of Charcot‐Marie‐Tooth (CMT) and associated neuropathies. Results We report the case of a 35‐year‐old male, who had presented CMT and hearing loss since childhood associated to bilateral optic neuropathy without any sign of retinitis pigmentosa. A new hemizygous variant on chromosomic position X:106,882,604, in the PRPS1 gene, c.202A > T, p.(Met68Leu) was found. This change is predicted to lead to an altered affinity between the different subunits in the dimer, thereby may prevent the hexamer formation. Conclusion CMTX5 is probably under‐diagnosed, as an overlap among the different features due to PRPS1 exists. Patients who developed polyneuropathy associated to sensorineural deafness and optic atrophy during childhood should be assessed for PRPS1.
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Affiliation(s)
- Justine Lerat
- Univ. Limoges, MMNP, Limoges, France.,CHU Limoges, Service Oto-Rhino-Laryngologie et Chirurgie Cervico-Faciale, Limoges, France
| | - Corinne Magdelaine
- Univ. Limoges, MMNP, Limoges, France.,CHU Limoges, Service Biochimie et Génétique Moléculaire, Limoges, France
| | - Paco Derouault
- CHU Limoges, Service Biochimie et Génétique Moléculaire, Limoges, France
| | - Hélène Beauvais-Dzugan
- Univ. Limoges, MMNP, Limoges, France.,CHU Limoges, Service Biochimie et Génétique Moléculaire, Limoges, France
| | - Eric Bieth
- CHU Toulouse, Service Génétique Médicale, Toulouse, France
| | - Blandine Acket
- CHU Toulouse, Explorations neurophysiologiques, Centre SLA, Centre de référence de pathologie neuromusculaire, Toulouse, France
| | - Marie-Christine Arne-Bes
- CHU Toulouse, Explorations neurophysiologiques, Centre SLA, Centre de référence de pathologie neuromusculaire, Toulouse, France
| | - Franck Sturtz
- Univ. Limoges, MMNP, Limoges, France.,CHU Limoges, Service Biochimie et Génétique Moléculaire, Limoges, France
| | - Anne-Sophie Lia
- Univ. Limoges, MMNP, Limoges, France.,CHU Limoges, Service Biochimie et Génétique Moléculaire, Limoges, France
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11
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Meng L, Wang K, Lv H, Wang Z, Zhang W, Yuan Y. A novel mutation in PRPS1 causes X-linked Charcot-Marie-Tooth disease-5. Neuropathology 2019; 39:342-347. [PMID: 31434166 DOI: 10.1111/neup.12589] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 05/16/2019] [Accepted: 06/28/2019] [Indexed: 12/20/2022]
Abstract
X-linked Charcot-Marie-Tooth disease-5 (CMTX5) is a rare hereditary disorder caused by mutations in the gene for phosphoribosyl pyrophosphate synthetase-1 (PRPS1). We investigated a boy with a novel PRPS1 mutation (c.334G>C, p.V112L) via genetic, neuropathological and enzymatic tests. The proband was a 13-year-old boy with congenital non-syndromic sensorineural deafness. At 3 year old, he developed progressive distal weakness of all limbs with muscle atrophy of both hands and shanks. Nerve conduction study revealed the loss of sensory nerve action potentials, and slowing down of motor nerve conduction velocities with a decrease of amplitudes of compound motor action potentials. Visual evoked potentials and brainstem auditory evoked potentials were not bilaterally evocable. Sural biopsy proved the loss of myelinated nerve fibers, with axonal degeneration, regenerating clusters and onion bulbs. Enzymatically, PRPS1 activity was close to zero in the proband and mildly reduced in his mother, compared with controls. To our knowledge, this is the first report of CMTX5 in a Chinese population. The genetic finding has expanded the genotypic spectrum of PRPS1 mutations.
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Affiliation(s)
- Lingchao Meng
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Kang Wang
- Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, Tsinghua University, Beijing, China
| | - He Lv
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Wei Zhang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing, China
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12
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DeSmidt AA, Zou B, Grati M, Yan D, Mittal R, Yao Q, Richmond MT, Denyer S, Liu XZ, Lu Z. Zebrafish Model for Nonsyndromic X-Linked Sensorineural Deafness, DFNX1. Anat Rec (Hoboken) 2019; 303:544-555. [PMID: 30874365 DOI: 10.1002/ar.24115] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 08/23/2018] [Accepted: 09/05/2018] [Indexed: 11/08/2022]
Abstract
Hereditary deafness is often a neurosensory disorder and affects the quality of life of humans. Only three X-linked genes (POU class 3 homeobox 4 (POU3F4), phosphoribosyl pyrophosphate synthetase 1 (PRPS1), and small muscle protein X-linked (SMPX)) are known to be involved in nonsyndromic hearing loss. Four PRPS1 missense mutations have been found to associate with X-linked nonsyndromic sensorineural deafness (DFNX1/DFN2) in humans. However, a causative relationship between PRPS1 mutations and hearing loss in humans has not been well studied in any animal model. Phosphoribosyl pyrophosphate synthetase 1 (PRS-I) is highly conserved in vertebrate taxa. In this study, we used the zebrafish as a model to investigate the auditory role of zebrafish orthologs (prps1a and prps1b) of the human PRPS1 gene with whole mount in situ hybridization, reverse transcription polymerase chain reaction, phenotypic screening, confocal imaging, and electrophysiological methods. We found that both prps1a and prps1b genes were expressed in the inner ear of zebrafish. Splice-blocking antisense morpholino oligonucleotides (MO1 and MO2) caused exon-2 skip and intron-2 retention of prps1a and exon-2 skip and intron-1 retention of prps1b to knock down functions of the genes, respectively. MO1 and MO2 morphants had smaller otic vesicles and otoliths, fewer inner ear hair cells, and lower microphonic response amplitude and sensitivity than control zebrafish. Therefore, knockdown of either prps1a or prps1b resulted in significant sensorineural hearing loss in zebrafish. We conclude that the prps1 genes are essential for hearing in zebrafish, which has the potential to help us understand the biology of human deafness DFNX1/DFN2. Anat Rec, 303:544-555, 2020. © 2019 American Association for Anatomy.
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Affiliation(s)
| | - Bing Zou
- Department of Biology, University of Miami, Coral Gables, Florida.,Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - M'hamed Grati
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Qi Yao
- Department of Biology, University of Miami, Coral Gables, Florida.,Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | | | - Steven Denyer
- Department of Biology, University of Miami, Coral Gables, Florida
| | - Xue Zhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida.,Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Zhongmin Lu
- Department of Biology, University of Miami, Coral Gables, Florida.,Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida.,Neuroscience Program, University of Miami, Miami, Florida.,International Center for Marine Studies, Shanghai Ocean University, Shanghai, People's Republic of China
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13
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Nishikura N, Yamagata T, Morimune T, Matsui J, Sokoda T, Sawai C, Sakaue Y, Higuchi Y, Hashiguchi A, Takashima H, Takeuchi Y, Maruo Y. X-linked Charcot-Marie-Tooth disease type 5 with recurrent weakness after febrile illness. Brain Dev 2019; 41:201-204. [PMID: 30177296 DOI: 10.1016/j.braindev.2018.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/23/2018] [Accepted: 08/20/2018] [Indexed: 02/06/2023]
Abstract
X-linked Charcot-Marie-Tooth disease type 5 (CMTX5) is an X-linked disorder characterized by early-onset sensorineural hearing impairment, peripheral neuropathy, and progressive optic atrophy. It is caused by a loss-of-function mutation in the phosphoribosyl pyrophosphate synthetase 1 gene (PRPS1), which encodes isoform I of phosphoribosyl pyrophosphate synthetase (PRS-I). A decreased activity leads to nonsyndromic sensorineural deafness (DFN2), CMTX5, and Arts syndrome depending upon residual PRS-I activity. Clinical and neurophysiological features of pediatric CMTX5 are poorly defined. We report two male siblings with peripheral neuropathy and prelingual sensorineural hearing loss who carried a novel c.319A>G (p.Ile107Val) PRPS1 missense mutation. They exhibited recurrent episodes of transient proximal muscle weakness, showing Gowers' sign and waddling gait after suffering from febrile illness. This transient weakness has not been previously reported in CMTX5. A patient with Arts syndrome was reported to have transient proximal weakness after febrile illness. The transient weakness presenting in both CMTX5 and Arts syndrome suggests an overlap of signs and a continuous spectrum of PRS-I hypoactivity disease. Children presenting with transient neurological signs should be evaluated for peripheral neuropathy and consider genetic analysis for PRPS1.
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Affiliation(s)
- Noriko Nishikura
- Department of Pediatrics, Shiga University of Medical Science, Otsu 520-2192, Japan.
| | - Takanori Yamagata
- Department of Pediatrics, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Takao Morimune
- Department of Pediatrics, Shiga University of Medical Science, Otsu 520-2192, Japan
| | - Jun Matsui
- Department of Pediatrics, Shiga University of Medical Science, Otsu 520-2192, Japan
| | - Tatsuyuki Sokoda
- Department of Pediatrics, Shiga University of Medical Science, Otsu 520-2192, Japan
| | - Chihiro Sawai
- Department of Pediatrics, Shiga University of Medical Science, Otsu 520-2192, Japan
| | - Yuko Sakaue
- Department of Pediatrics, Shiga University of Medical Science, Otsu 520-2192, Japan
| | - Yujiro Higuchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Akihiro Hashiguchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Yoshihiro Takeuchi
- Department of Pediatrics, Shiga University of Medical Science, Otsu 520-2192, Japan
| | - Yoshihiro Maruo
- Department of Pediatrics, Shiga University of Medical Science, Otsu 520-2192, Japan
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14
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Wang B, Li X, Wang J, Liu L, Xie Y, Huang S, Pakhrin PS, Jin Q, Zhu C, Tang B, Niu Q, Zhang R. A novel AIFM1 mutation in a Chinese family with X-linked Charcot-Marie-Tooth disease type 4. Neuromuscul Disord 2018; 28:652-659. [PMID: 30031633 DOI: 10.1016/j.nmd.2018.05.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 04/05/2018] [Accepted: 05/20/2018] [Indexed: 11/16/2022]
Abstract
X-linked Charcot-Marie-Tooth disease type 4 (CMTX4), caused by AIFM1 (Apoptosis-Inducing Factor, Mitochondrion associated 1) mutations and associated with deafness and cognitive impairment, is a rare subtype of Charcot-Marie-Tooth disease. Here, we report a novel missense variant of AIFM1 in a X-linked recessive Chinese family with childhood-onset, slowly progressive, isolated axonal motor and sensory neuropathy. Calf magnetic resonance imaging revealed fatty infiltration and atrophy severely involving the muscles of peroneal compartment. Pathologies exhibited abnormal mitochondrial morphology and accumulation in axoplasm of nerve fiber and subsarcolemmal area of muscle. A hemizygous variant (c.513G>A, p.Met171Ile) in the family was identified and was classified as likely pathogenic according to the standards and guidelines of the American College of Medical Genetics and Genomics. Our report expands the genetic spectrum of diseases related to AIFM1 mutations and indicates that fatty infiltration and atrophy of muscles in the peroneal compartment may be a feature of CMTX4 in early stage.
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Affiliation(s)
- Binghao Wang
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Xiaobo Li
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Junpu Wang
- Department of Pathology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Lei Liu
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Yongzhi Xie
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Shunxiang Huang
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Pukar Singh Pakhrin
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Qingwen Jin
- Department of Neurology, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Chunmei Zhu
- Department of Neurology, Xuyi County Hospital of T.C.M, Huaian, Jiangsu 211700, China
| | - Beisha Tang
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan 410008, China
| | - Qi Niu
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China.
| | - Ruxu Zhang
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China.
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15
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Ma Y, An X, Guan X, Kong Q, Wang Y, Li P, Meng Y, Cui Y, Wen X, Guo Y, Shen Y, Yu J. High expression of PRPS1 induces an anti-apoptotic effect in B-ALL cell lines and predicts an adverse prognosis in Chinese children with B-ALL. Oncol Lett 2018. [PMID: 29541198 PMCID: PMC5835884 DOI: 10.3892/ol.2018.7903] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Phosphoribosyl pyrophosphate synthetase 1 (PRPS1) is closely associated with a number of diseases; however, its influence in B-cell acute lymphoblastic leukemia (B-ALL) and the potential molecular mechanisms involved remain unclear. The present study aimed to evaluate the expression of PRPS1 in Chinese children with B-ALL and to investigate the mechanism of action of PRPS1 in this disease. A Cell Counting Kit-8 (CCK-8) assay was performed to examine the proliferation of B-ALL Sup-B15 and Raji cells, and flow cytometric analysis was conducted to determine the cell cycle distribution and rate of apoptosis. The mRNA and protein expression levels of PRPS1, MYC proto-oncogene, bHLH transcription factor, cyclin E1, B-cell lymphoma-2 (Bcl-2), cyclin dependent kinase 2 and caspase-3 were detected by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. Elevated PRPS1 expression was associated with a high-risk stratification and poor prognosis in patients with B-ALL. Furthermore, overexpression of PRPS1 accelerated the growth of and inhibited apoptosis in Sup-B15 and Raji cells as well as increasing the expression of Bcl-2 to induce an anti-apoptotic effect in B-ALL cell lines. The results of the present study indicate that PRPS1 regulates multiple processes in B-ALL and may be an attractive therapeutic target.
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Affiliation(s)
- Yimei Ma
- Department of Hematology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.,Chongqing Key Laboratory of Pediatrics, Chongqing 400014, P.R. China.,China International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing Medical University, Chongqing 400014, P.R. China
| | - Xizhou An
- Department of Hematology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.,Chongqing Key Laboratory of Pediatrics, Chongqing 400014, P.R. China.,China International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing Medical University, Chongqing 400014, P.R. China
| | - Xianmin Guan
- Department of Hematology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.,Chongqing Key Laboratory of Pediatrics, Chongqing 400014, P.R. China.,China International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing Medical University, Chongqing 400014, P.R. China
| | - Qinglin Kong
- Department of Hematology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.,Chongqing Key Laboratory of Pediatrics, Chongqing 400014, P.R. China.,China International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing Medical University, Chongqing 400014, P.R. China
| | - Yanzhen Wang
- Department of Hematology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.,Chongqing Key Laboratory of Pediatrics, Chongqing 400014, P.R. China.,China International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing Medical University, Chongqing 400014, P.R. China
| | - Pengfei Li
- Department of Hematology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.,Chongqing Key Laboratory of Pediatrics, Chongqing 400014, P.R. China.,China International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing Medical University, Chongqing 400014, P.R. China
| | - Yan Meng
- Department of Hematology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.,Chongqing Key Laboratory of Pediatrics, Chongqing 400014, P.R. China.,China International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing Medical University, Chongqing 400014, P.R. China
| | - Yinghui Cui
- Department of Hematology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.,Chongqing Key Laboratory of Pediatrics, Chongqing 400014, P.R. China.,China International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing Medical University, Chongqing 400014, P.R. China
| | - Xianhao Wen
- Department of Hematology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.,Chongqing Key Laboratory of Pediatrics, Chongqing 400014, P.R. China.,China International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing Medical University, Chongqing 400014, P.R. China
| | - Yuxia Guo
- Department of Hematology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.,Chongqing Key Laboratory of Pediatrics, Chongqing 400014, P.R. China.,China International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing Medical University, Chongqing 400014, P.R. China
| | - Yali Shen
- Department of Hematology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.,Chongqing Key Laboratory of Pediatrics, Chongqing 400014, P.R. China.,China International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing Medical University, Chongqing 400014, P.R. China
| | - Jie Yu
- Department of Hematology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.,Chongqing Key Laboratory of Pediatrics, Chongqing 400014, P.R. China.,China International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing Medical University, Chongqing 400014, P.R. China
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16
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Kim SY, Kim AR, Kim NKD, Lee C, Han JH, Kim MY, Jeon EH, Park WY, Mittal R, Yan D, Liu XZ, Choi BY. Functional characterization of a novel loss-of-function mutation of PRPS1 related to early-onset progressive nonsyndromic hearing loss in Koreans (DFNX1): Potential implications on future therapeutic intervention. J Gene Med 2017; 18:353-358. [PMID: 27886419 DOI: 10.1002/jgm.2935] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 11/22/2016] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The symptoms of phosphoribosyl pyrophosphate synthetase 1 (PRPS1) deficiency diseases have been reported to be alleviated by medication. In the present study, we report biochemical data that favor PRPS1 deficiency-related hearing loss as a potential target for pharmaceutical treatment. METHODS We recruited 42 probands from subjects aged less than 15 years with a moderate degree of nonsyndromic autosomal-recessive or sporadic sensorineural hearing loss (SNHL) in at least one side. Molecular genetic testing, including targeted exome sequencing (TES) of 129 genes for deafness, and in silico prediction were performed. RESULTS A strong candidate variant (p.A82P) of PRPS1 is co-segregated with SNHL in X-linked recessive inheritance from one Korean multiplex SNHL family. Subsequent measurement of in vitro enzymatic activities of PRPS1 from erythrocytes of affected and unaffected family members, as well as unrelated normal controls, confirmed a pathogenic role of this variant. In detail, compared to normal hearing controls (0.23-0.26 nmol/ml/h), the proband, the affected sibling and their normal hearing mother demonstrated a significantly decreased PRPS1 enzymatic activity (0.07, 0.03 and 0.11 nmol/ml/h, respectively). This novel loss-of-function mutation of PRPS1 (p.A82P) is the ninth and sixth most reported mutation in the world and in Asia, respectively. CONCLUSIONS DFNX1 was found to account for approximately 2.4% (1/42) of moderate SNHL in a Korean pediatric population. Confirmation of PRPS1 activity deficiency and an audiologic phenotype that initially begins in a milder form of SNHL, as in our family, should indicate the need for rigorous genetic screening as early as possible.
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Affiliation(s)
- So Young Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, CHA Bundang Medical Center, CHA University, Seongnam, South Korea
| | - Ah Reum Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - Nayoung K D Kim
- Samsung Genome Institute, Samsung Medical Center, Seoul, South Korea
| | - Chung Lee
- Samsung Genome Institute, Samsung Medical Center, Seoul, South Korea.,Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Suwon, South Korea
| | - Jin Hee Han
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea
| | - Min Young Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea
| | - Eun-Hee Jeon
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea
| | - Woong-Yang Park
- Samsung Genome Institute, Samsung Medical Center, Seoul, South Korea.,Department of Molecular Cell Biology, School of Medicine, Sungkyunkwan University, Seoul, South Korea
| | - Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Xue Zhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Byung Yoon Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea.,Wide River Institute of Immunology, Seoul National University College of Medicine, Hongcheon, South Korea
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17
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Porrmann J, Betcheva-Krajcir E, Di Donato N, Kahlert AK, Schallner J, Rump A, Schröck E, Dobritzsch D, Roelofsen J, van Kuilenburg ABP, Tzschach A. Novel PRPS1 gain-of-function mutation in a patient with congenital hyperuricemia and facial anomalies. Am J Med Genet A 2017; 173:2736-2742. [PMID: 28742244 DOI: 10.1002/ajmg.a.38359] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 05/10/2017] [Accepted: 06/21/2017] [Indexed: 11/08/2022]
Abstract
Phosphoribosylpyrophosphate synthetase (PRPPS) superactivity (OMIM 300661) is a rare inborn error of purine metabolism that is caused by gain-of-function mutations in the X-chromosomal gene PRPS1 (Xq22.3). Clinical characteristics include congenital hyperuricemia and hyperuricosuria, gouty arthritis, urolithiasis, developmental delay, hypotonia, recurrent infections, short stature, and hearing loss. Only eight families with PRPPS superactivity and PRPS1 gain-of-function mutations have been reported to date. We report on a 7-year-old boy with congenital hyperuricemia, urolithiasis, developmental delay, short stature, hypospadias, and facial dysmorphisms. His mother also suffered from hyperuricemia that was diagnosed at age 13 years. A novel PRPS1 missense mutation (c.573G>C, p.[Leu191Phe]) was detected in the proband and his mother. Enzyme activity analysis confirmed superactivity of PRPP synthetase. Analysis of the crystal structure of human PRPPS suggests that the Leu191Phe mutation affects the architecture of both allosteric sites, thereby preventing the allosteric inhibition of the enzyme. The family reported here broadens the clinical spectrum of PRPPS superactivity and indicates that this rare metabolic disorder might be associated with a recognizable facial gestalt.
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Affiliation(s)
- Joseph Porrmann
- Institut für Klinische Genetik, Technische Universität Dresden, Dresden, Germany
| | | | - Nataliya Di Donato
- Institut für Klinische Genetik, Technische Universität Dresden, Dresden, Germany
| | - Anne-Karin Kahlert
- Institut für Klinische Genetik, Technische Universität Dresden, Dresden, Germany
| | - Jens Schallner
- Children's hospital, Universitätsklinikum Carl Gustav Carus, Dresden, Germany
| | - Andreas Rump
- Institut für Klinische Genetik, Technische Universität Dresden, Dresden, Germany
| | - Evelin Schröck
- Institut für Klinische Genetik, Technische Universität Dresden, Dresden, Germany
| | - Doreen Dobritzsch
- Department of Chemistry, Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Jeroen Roelofsen
- Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Academic Medical Centre, Emma Children's Hospital, University of Amsterdam, Amsterdam, The Netherlands
| | - André B P van Kuilenburg
- Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Academic Medical Centre, Emma Children's Hospital, University of Amsterdam, Amsterdam, The Netherlands
| | - Andreas Tzschach
- Institut für Klinische Genetik, Technische Universität Dresden, Dresden, Germany
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18
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Additive reductions in zebrafish PRPS1 activity result in a spectrum of deficiencies modeling several human PRPS1-associated diseases. Sci Rep 2016; 6:29946. [PMID: 27425195 PMCID: PMC4947902 DOI: 10.1038/srep29946] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 06/27/2016] [Indexed: 01/08/2023] Open
Abstract
Phosphoribosyl pyrophosphate synthetase-1 (PRPS1) is a key enzyme in nucleotide biosynthesis, and mutations in PRPS1 are found in several human diseases including nonsyndromic sensorineural deafness, Charcot-Marie-Tooth disease-5, and Arts Syndrome. We utilized zebrafish as a model to confirm that mutations in PRPS1 result in phenotypic deficiencies in zebrafish similar to those in the associated human diseases. We found two paralogs in zebrafish, prps1a and prps1b and characterized each paralogous mutant individually as well as the double mutant fish. Zebrafish prps1a mutants and prps1a;prps1b double mutants showed similar morphological phenotypes with increasingly severe phenotypes as the number of mutant alleles increased. Phenotypes included smaller eyes and reduced hair cell numbers, consistent with the optic atrophy and hearing impairment observed in human patients. The double mutant also showed abnormal development of primary motor neurons, hair cell innervation, and reduced leukocytes, consistent with the neuropathy and recurrent infection of the human patients possessing the most severe reductions of PRPS1 activity. Further analyses indicated the phenotypes were associated with a prolonged cell cycle likely resulting from reduced nucleotide synthesis and energy production in the mutant embryos. We further demonstrated the phenotypes were caused by delays in the tissues most highly expressing the prps1 genes.
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19
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Soldà G, Caccia S, Robusto M, Chiereghin C, Castorina P, Ambrosetti U, Duga S, Asselta R. First independent replication of the involvement of LARS2 in Perrault syndrome by whole-exome sequencing of an Italian family. J Hum Genet 2015; 61:295-300. [PMID: 26657938 PMCID: PMC4817218 DOI: 10.1038/jhg.2015.149] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 11/09/2015] [Accepted: 11/10/2015] [Indexed: 11/24/2022]
Abstract
Perrault syndrome (MIM #233400) is a rare autosomal recessive disorder characterized by ovarian dysgenesis and primary ovarian insufficiency in females, and progressive hearing loss in both genders. Recently, mutations in five genes (HSD17B4, HARS2, CLPP, LARS2, and C10ORF2) were found to be responsible for Perrault syndrome, although they do not account for all cases of this genetically heterogeneous condition. We used whole-exome sequencing to identify pathogenic variants responsible for Perrault syndrome in an Italian pedigree with two affected siblings. Both patients were compound heterozygous for two novel missense variants within the mitochondrial leucyl-tRNA synthetase (LARS2), NM_015340.3:c.899C>T(p.Thr300Met) and c.1912G>A(p.Glu638Lys). Both variants co-segregated with the phenotype in the family. p.Thr300 and p.Glu638 are evolutionary conserved residues, and are located respectively within the editing domain and immediately before the catalytically important KMSKS motif. Homology modeling using as template the E. coli leucyl-tRNA synthetase provided further insights on the possible pathogenic effects of the identified variants. This represents the first independent replication of the involvement of LARS2 mutations in Perrault syndrome, contributing valuable information for the further understanding of this disease.
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Affiliation(s)
- Giulia Soldà
- Department of Biomedical Sciences, Humanitas University, Milan, Italy.,Humanitas Clinical and Research Center, Milan, Italy
| | - Sonia Caccia
- Department of Biomedical and Clinical Sciences "Luigi Sacco", Università degli Studi di Milano - LITA Vialba, Milan, Italy
| | - Michela Robusto
- Department of Biomedical Sciences, Humanitas University, Milan, Italy.,Humanitas Clinical and Research Center, Milan, Italy
| | - Chiara Chiereghin
- Department of Biomedical Sciences, Humanitas University, Milan, Italy.,Humanitas Clinical and Research Center, Milan, Italy
| | - Pierangela Castorina
- UO Audiologia, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Umberto Ambrosetti
- UO Audiologia, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy.,Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, Milan, Italy
| | - Stefano Duga
- Department of Biomedical Sciences, Humanitas University, Milan, Italy.,Humanitas Clinical and Research Center, Milan, Italy
| | - Rosanna Asselta
- Department of Biomedical Sciences, Humanitas University, Milan, Italy.,Humanitas Clinical and Research Center, Milan, Italy
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Mutations in PRPS1 causing syndromic or nonsyndromic hearing impairment: intrafamilial phenotypic variation complicates genetic counseling. Pediatr Res 2015; 78:97-102. [PMID: 25785835 DOI: 10.1038/pr.2015.56] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 12/06/2014] [Indexed: 11/08/2022]
Abstract
BACKGROUND PRPS1 encodes isoform I of phosphoribosylpyrophosphate synthetase (PRS-I), a key enzyme in nucleotide biosynthesis. Different missense mutations in PRPS1 cause a variety of disorders that include PRS-I superactivity, nonsyndromic sensorineural hearing impairment, Charcot-Marie-Tooth disease, and Arts syndrome. It has been proposed that each mutation would result in a specific phenotype, depending on its effects on the structure and function of the enzyme. METHODS Thirteen Spanish unrelated families segregating X-linked hearing impairment were screened for PRPS1 mutations by Sanger sequencing. In two positive pedigrees, segregation of mutations was studied, and clinical data from affected subjects were compared. RESULTS We report two novel missense mutations in PRPS1, p.Ile275Thr and p.Gly306Glu, which were found in the propositi of two unrelated Spanish families, both subjects presenting with nonsyndromic hearing impairment. Further investigation revealed syndromic features in other hemizygous carriers from one of the pedigrees. Sequencing of genes that are functionally related to PRPS1 did not reveal any candidate variant that might act as a phenotype modifier. CONCLUSION This case of intrafamilial phenotypic variation associated with a single PRPS1 mutation complicates the genotype-phenotype correlations, which makes genetic counseling of mutation carriers difficult because of the wide spectrum of severity of the associated disorders.
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Association of PRPS1 Mutations with Disease Phenotypes. DISEASE MARKERS 2015; 2015:127013. [PMID: 26089585 PMCID: PMC4458296 DOI: 10.1155/2015/127013] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 05/06/2015] [Indexed: 01/01/2023]
Abstract
Phosphoribosylpyrophosphate synthetase 1 (PRPS1) codes for PRS-I enzyme that catalyzes the first step of nucleotide synthesis. PRPS1 gene mutations have been implicated in a number of human diseases. Recently, new mutations in PRPS1 have been identified that have been associated with novel phenotypes like diabetes insipidus expanding the spectrum of PRPS1-related diseases. The purpose of this review is to evaluate current literature on PRPS1-related syndromes and summarize potential therapies. The overexpression of PRPS1 results in PRS-I superactivity resulting in purine overproduction. Patients with PRS-I superactivity demonstrate uric acid overproduction, hypotonia, ataxia, neurodevelopment abnormalities, and postlingual hearing impairment. On the other hand, decreased activity leads to X-linked nonsyndromic sensorineural deafness (DFNX-2), Charcot-Marie-Tooth disease-5 (CMTX5), and Arts syndrome depending on the residual activity of PRS-I. Mild PRS-I deficiency (DFNX-2) results in non-syndromic progressive hearing loss whereas moderate PRS-I deficiency (CMTX5) and severe PRS-I deficiency (Arts syndrome) present with peripheral or optic neuropathy, prelingual progressive sensorineural hearing loss, and central nervous system impairment. Currently, purine replacement via S-adenosylmethionine (SAM) supplementation in patients with Arts syndrome appears to improve their condition. This suggests that SAM supplementation can alleviate symptoms of PRPS1 deficient patients and open new avenues of therapeutic intervention.
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