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Fiorito V, Tolosano E. Unearthing FLVCR1a: tracing the path to a vital cellular transporter. Cell Mol Life Sci 2024; 81:166. [PMID: 38581583 PMCID: PMC10998817 DOI: 10.1007/s00018-024-05205-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 03/08/2024] [Accepted: 03/13/2024] [Indexed: 04/08/2024]
Abstract
The Feline Leukemia Virus Subgroup C Receptor 1a (FLVCR1a) is a member of the SLC49 Major Facilitator Superfamily of transporters. Initially recognized as the receptor for the retrovirus responsible of pure red cell aplasia in cats, nearly two decades since its discovery, FLVCR1a remains a puzzling transporter, with ongoing discussions regarding what it transports and how its expression is regulated. Nonetheless, despite this, the substantial body of evidence accumulated over the years has provided insights into several critical processes in which this transporter plays a complex role, and the health implications stemming from its malfunction. The present review intends to offer a comprehensive overview and a critical analysis of the existing literature on FLVCR1a, with the goal of emphasising the vital importance of this transporter for the organism and elucidating the interconnections among the various functions attributed to this transporter.
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Affiliation(s)
- Veronica Fiorito
- Molecular Biotechnology Center (MBC) "Guido Tarone", Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126, Turin, Italy
| | - Emanuela Tolosano
- Molecular Biotechnology Center (MBC) "Guido Tarone", Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126, Turin, Italy.
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Li Z, Li Y, Chu X, Du K, Tang Y, Xie Z, Yu M, Deng J, Lv H, Zhang W, Wang Z, Meng L, Yuan Y. Novel mutations in FLVCR1 cause tremors, sensory neuropathy with retinitis pigmentosa. Neuropathology 2024; 44:87-95. [PMID: 37469134 DOI: 10.1111/neup.12936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/21/2023]
Abstract
The mutations of the feline leukemia virus subgroup C receptor-related protein 1 (FLVCR1) cause ataxia with retinitis pigmentosa. Recent studies indicated a large variation in the phenotype of FLVCR1-associated diseases. In this report, we describe an adult male who manifested first with tremors in his third decade, followed by retinitis pigmentosa, sensory ataxia, and sensory neuropathy in his fourth decade. While retinitis pigmentosa and sensory ataxia are well-recognized features of FLVCR1-associated disease, tremor is rarely described. Whole-exome sequencing revealed novel compound heterozygous pathogenic FLVCR1 variants: c.498 G > A; p.(Trp166*) and c.369 T > G; p.(Phe123Leu). In addition, we have highlighted the ultrastructural abnormalities of the sural biopsy in this patient.
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Affiliation(s)
- Zhenyu Li
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Yize Li
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Xujun Chu
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Kang Du
- Department of Neurology, Qujing First People's Hospital, Qujing, China
| | - Yuwei Tang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Zhiying Xie
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Meng Yu
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Jianwen Deng
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - He Lv
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Wei Zhang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory for Neurovascular Disease Discovery, Peking University First Hospital, Beijing, China
- Key Laboratory for Neuroscience, National Health Commission of the People's Republic of China, Peking University, Beijing, China
| | - Lingchao Meng
- Department of Neurology, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory for Neurovascular Disease Discovery, Peking University First Hospital, Beijing, China
- Key Laboratory for Neuroscience, National Health Commission of the People's Republic of China, Peking University, Beijing, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory for Neurovascular Disease Discovery, Peking University First Hospital, Beijing, China
- Key Laboratory for Neuroscience, National Health Commission of the People's Republic of China, Peking University, Beijing, China
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Vaughan DP, Costello DJ. Extending the phenotype of posterior column ataxia with retinitis pigmentosa caused by variants in FLVCR1. Am J Med Genet A 2021; 188:1259-1262. [PMID: 34931442 DOI: 10.1002/ajmg.a.62612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 11/12/2021] [Accepted: 11/16/2021] [Indexed: 11/12/2022]
Abstract
Posterior column ataxia with retinitis pigmentosa (PCARP) is a rare autosomal recessive condition due to variants in the Feline Leukemia Virus Subgroup C Cellular Receptor 1 (FLVCR1) gene which was first described in 1997. In this article, we describe a young female patient with a childhood diagnosis of retinitis pigmentosa and learning disability, presenting with progressive ataxia from her late teens. Examination revealed spastic lower limbs with absent reflexes, and reduced vibration and joint position sensation. Magnetic resonance imaging showed normal cerebellar volume and linear signal abnormality within the posterior columns of her spinal cord. Trio exome analysis confirmed two variants in FLVCR1. Our case extends the phenotype of PCARP to include learning disability and developmental delay, and highlights the importance of considering this rare condition in young adults or children with visual impairment and ataxia.
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Affiliation(s)
- David P Vaughan
- Department of Neurology, Cork University Hospital, Cork, Ireland
| | - Daniel J Costello
- Department of Neurology, Cork University Hospital, Cork, Ireland.,College of Medicine and Health, University College Cork, Cork, Ireland
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Lachmann ES, Mautone L, Dulz S. Isolated juvenile macular dystrophy without posterior column ataxia associated with FLVCR1 mutation. Ophthalmic Genet 2021; 42:784-786. [PMID: 34433355 DOI: 10.1080/13816810.2021.1970196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Eva S Lachmann
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Luca Mautone
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Simon Dulz
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Yang XR, Benson MD, MacDonald IM, Innes AM. A diagnostic approach to syndromic retinal dystrophies with intellectual disability. Am J Med Genet C Semin Med Genet 2020; 184:538-570. [PMID: 32918368 DOI: 10.1002/ajmg.c.31834] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/30/2020] [Accepted: 08/05/2020] [Indexed: 12/20/2022]
Abstract
Inherited retinal dystrophies are a group of monogenic disorders that, as a whole, contribute significantly to the burden of ocular disease in both pediatric and adult patients. In their syndromic forms, retinal dystrophies can be observed in association with intellectual disability, frequently alongside other systemic manifestations. There are now over 80 genes implicated in syndromic retinal dystrophies with intellectual disability. Identifying and accurately characterizing these disorders allows the clinician to narrow the differential diagnosis, evaluate for relevant associated features, arrive at a timely and accurate diagnosis, and address both sight-threatening ocular manifestations and morbidity-causing systemic manifestations. The co-occurrence of retinal dystrophy and intellectual disability in an individual can be challenging to investigate, diagnose, and counsel given the considerable phenotypic and genotypic heterogeneity that exists within this broad group of disorders. We performed a review of the current literature and propose an algorithm to facilitate the evaluation, and clinical and mechanistic classification, of these individuals.
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Affiliation(s)
- Xiao-Ru Yang
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Matthew D Benson
- Department of Ophthalmology, University of Alberta, Edmonton, Alberta, Canada
| | - Ian M MacDonald
- Department of Ophthalmology, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
| | - A Micheil Innes
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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Grudzinska Pechhacker MK, Yoon G, Hazrati LN, Maynes J, MacDonald H, Tavares E, Vincent A, Heon E. FLVCR1-related disease as a rare cause of retinitis pigmentosa and hereditary sensory autonomic neuropathy. Eur J Med Genet 2020; 63:104037. [PMID: 32822874 DOI: 10.1016/j.ejmg.2020.104037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 06/18/2020] [Accepted: 08/08/2020] [Indexed: 11/20/2022]
Abstract
FLVCR1 encodes for a transmembrane heme exporter protein and it is known to cause a rare form of syndromic retinitis pigmentosa: posterior column ataxia with retinitis pigmentosa. Recently, the FLVCR1-associated phenotype has been expanded with sporadic reports of hereditary sensory-autonomic neuropathy or non-syndromic retinitis pigmentosa. Here, we report a 23-year- old female with early onset hypomyelinating sensory-autonomic neuropathy and retinitis pigmentosa. Both features were present since childhood. The patient developed signs of advanced retinitis pigmentosa by the age of 10 years leading to legal blindness after the age of 18. Following candidate gene panel testing, which was negative, whole exome sequencing revealed compound heterozygous pathogenic FLVCR1 variants: NM_014053.3: c.3G > T; p.(Met1?) and NM_014053.3: c.730G > A; p.(Gly244Ser), the latter variant is novel. In this report we highlight the association of retinitis pigmentosa with hypomyelinating sensory-autonomic neuropathy, which could be underdiagnosed due to variable severity. To summarize, the phenotypic heterogeneity of FLVCR1 variants is broad and should include retinitis pigmentosa along with range of neurological features.
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Chiabrando D, Bertino F, Tolosano E. Hereditary Ataxia: A Focus on Heme Metabolism and Fe-S Cluster Biogenesis. Int J Mol Sci 2020; 21:ijms21113760. [PMID: 32466579 PMCID: PMC7312568 DOI: 10.3390/ijms21113760] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 05/21/2020] [Accepted: 05/22/2020] [Indexed: 02/07/2023] Open
Abstract
Heme and Fe-S clusters regulate a plethora of essential biological processes ranging from cellular respiration and cell metabolism to the maintenance of genome integrity. Mutations in genes involved in heme metabolism and Fe-S cluster biogenesis cause different forms of ataxia, like posterior column ataxia and retinitis pigmentosa (PCARP), Friedreich's ataxia (FRDA) and X-linked sideroblastic anemia with ataxia (XLSA/A). Despite great efforts in the elucidation of the molecular pathogenesis of these disorders several important questions still remain to be addressed. Starting with an overview of the biology of heme metabolism and Fe-S cluster biogenesis, the review discusses recent progress in the understanding of the molecular pathogenesis of PCARP, FRDA and XLSA/A, and highlights future line of research in the field. A better comprehension of the mechanisms leading to the degeneration of neural circuity responsible for balance and coordinated movement will be crucial for the therapeutic management of these patients.
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