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Kentab AY, Alsalloum Y, Labani M, Hudairi A, Hamad MH, Jamjoom DZ, Alwadei AH, Alhammad RM, Bashiri FA. Case Report: A rare treatable metabolic syndrome (Brown-Vialetto-Van Laere syndrome) masquerading as chronic inflammatory demyelinating polyneuropathy from Saudi Arabia. Front Pediatr 2024; 12:1377515. [PMID: 38745833 PMCID: PMC11091239 DOI: 10.3389/fped.2024.1377515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 04/12/2024] [Indexed: 05/16/2024] Open
Abstract
Background Brown-Vialetto-Van Laere (BVVL) syndrome is an extremely rare autosomal recessive progressive motoneuron disease that is caused by a defect in the riboflavin transporter genes SLC52A2 and SLC52A3. BVVL syndrome has a variable age of presentation, and it is characterized by progressive auditory neuropathy, bulbar palsy, stridor, muscle weakness, and respiratory compromise secondary to diaphragmatic and vocal cord paralysis. BVVL syndrome has a poor prognosis in the absence of treatment, including morbidity with quadriparesis and sensorineural hearing loss, with mortality in the younger age group. Early administration of riboflavin is associated with prolonged survival, low morbidity, and reversal of some clinical manifestations. Case presentation We describe an 18-month-old male infant with progressive pontobulbar palsy, loss of developmental milestones, and a clinical picture suggestive of chronic inflammatory demyelinating neuropathy. A nerve conduction study revealed axonal neuropathy, while molecular analysis revealed a homozygous mutation in one of the riboflavin transporter genes, SLC52A3, confirming BVVL syndrome. The patient needed long-term respiratory support and a gastrostomy tube to support feeding. With high-dose riboflavin supplementation, he experienced moderate recovery of motor function. Conclusion This report highlights the importance of considering BVVL syndrome in any patient who presents with the clinical phenotype of pontobulbar palsy and peripheral axonal neuropathy, as early riboflavin treatment may improve or halt disease progression, thus reducing the associated mortality and morbidity.
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Affiliation(s)
- Amal Y. Kentab
- Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- Department of Pediatrics, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Yara Alsalloum
- Department of Pediatrics, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Mai Labani
- Pediatric Intensive Care Unit, Department of Pediatrics, King Khalid University Hospital, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Abrar Hudairi
- Department of Pediatrics, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Muddathir H. Hamad
- Department of Pediatrics, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Dima Z. Jamjoom
- Department of Radiology and Medical Imaging, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Ali H. Alwadei
- Department of Pediatrics, King Saud University Medical City, Riyadh, Saudi Arabia
- Pediatric Neurology Department, National Neuroscience Institute, King Fahd Medical City, Riyadh, Saudi Arabia
| | - Reem M. Alhammad
- Department of Internal Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Fahad A. Bashiri
- Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- Department of Pediatrics, King Saud University Medical City, Riyadh, Saudi Arabia
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Murgia C, Dehlia A, Guthridge MA. New insights into the nutritional genomics of adult-onset riboflavin-responsive diseases. Nutr Metab (Lond) 2023; 20:42. [PMID: 37845732 PMCID: PMC10580530 DOI: 10.1186/s12986-023-00764-x] [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: 06/15/2023] [Accepted: 10/04/2023] [Indexed: 10/18/2023] Open
Abstract
Riboflavin, or vitamin B2, is an essential nutrient that serves as a precursor to flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN). The binding of the FAD and/or FMN cofactors to flavoproteins is critical for regulating their assembly and activity. There are over 90 proteins in the human flavoproteome that regulate a diverse array of biochemical pathways including mitochondrial metabolism, riboflavin transport, ubiquinone and FAD synthesis, antioxidant signalling, one-carbon metabolism, nitric oxide signalling and peroxisome oxidative metabolism. The identification of patients with genetic variants in flavoprotein genes that lead to adult-onset pathologies remains a major diagnostic challenge. However, once identified, many patients with adult-onset inborn errors of metabolism demonstrate remarkable responses to riboflavin therapy. We review the structure:function relationships of mutant flavoproteins and propose new mechanistic insights into adult-onset riboflavin-responsive pathologies and metabolic dysregulations that apply to multiple biochemical pathways. We further address the vexing issue of how the inheritance of genetic variants in flavoprotein genes leads to an adult-onset disease with complex symptomologies and varying severities. We also propose a broad clinical framework that may not only improve the current diagnostic rates, but also facilitate a personalized approach to riboflavin therapy that is low cost, safe and lead to transformative outcomes in many patients.
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Affiliation(s)
- Chiara Murgia
- The School of Agriculture, Food and Ecosystem Sciences (SAFES), Faculty of Science, The University of Melbourne, Parkville, Australia.
| | - Ankush Dehlia
- School of Life and Environmental Sciences, Deakin University, Burwood, Australia
| | - Mark A Guthridge
- School of Life and Environmental Sciences, Deakin University, Burwood, Australia
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Fennessy JR, Cornett KMD, Burns J, Menezes MP. Benefit of high-dose oral riboflavin therapy in riboflavin transporter deficiency. J Peripher Nerv Syst 2023; 28:308-316. [PMID: 37537696 DOI: 10.1111/jns.12587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 07/28/2023] [Accepted: 08/02/2023] [Indexed: 08/05/2023]
Abstract
Riboflavin transporter deficiency (RTD) is a progressive inherited neuropathy of childhood onset, characterised by pontobulbar palsy, sensorineural deafness, sensory ataxia, muscle weakness, optic atrophy and respiratory failure. Riboflavin supplementation is beneficial in short-term reports, but the quantum of benefit in various clinical domains is not well understood. A PubMed search was conducted, which identified 94 genetically confirmed cases of RTD who received riboflavin supplementation and had follow-up assessments. Information on the clinical and functional status before and after riboflavin supplementation was collected and analysed. Seventy-six of the 94 patients (80.9%) showed an overall improvement after riboflavin supplementation, and the remaining (19.1%) were stable, though some patients had deteriorations in individual domains with no reported deaths. The domains that had the highest rates of response to riboflavin supplementation were gross motor function (93.3% improved), bulbar palsy (91.3%) and ataxia (90.0%). Improvements were also seen in limb muscle weakness, audiology, facial nerve palsy and respiratory function. Despite treatment, many patients required assistance to ambulate and had severe or profound hearing loss and some remained gastrostomy or tracheostomy dependent. Riboflavin supplementation is a lifesaving intervention for patients with RTD and results in a profound improvement in several functional domains, with early diagnosis and treatment further improving outcomes. Despite treatment, patients are left with residual disability. There is a need to accurately measure functional outcomes in children with RTD and develop additional disease-modifying therapies.
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Affiliation(s)
- Jack R Fennessy
- Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Kayla M D Cornett
- Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
- Paediatric Gait Analysis Service of New South Wales, Sydney Children's Hospitals Network, Sydney, New South Wales, Australia
| | - Joshua Burns
- Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
- Paediatric Gait Analysis Service of New South Wales, Sydney Children's Hospitals Network, Sydney, New South Wales, Australia
| | - Manoj P Menezes
- Children's Hospital at Westmead Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
- TY Nelson Department of Neurology and Neurosurgery, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
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4
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Pinto WBVDR, Souza PVSD, Badia BML, Farias IB, Albuquerque Filho JMVD, Gonçalves EA, Machado RIL, Oliveira ASB. Adult-onset non-5q proximal spinal muscular atrophy: a comprehensive review. ARQUIVOS DE NEURO-PSIQUIATRIA 2021; 79:912-923. [PMID: 34706022 DOI: 10.1590/0004-282x-anp-2020-0429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 12/24/2020] [Indexed: 11/21/2022]
Abstract
BACKGROUND Adult-onset spinal muscular atrophy (SMA) represents an expanding group of inherited neurodegenerative disorders in clinical practice. OBJECTIVE This review aims to synthesize the main clinical, genetic, radiological, biochemical, and neurophysiological aspects related to the classical and recently described forms of proximal SMA. METHODS The authors performed a non-systematic critical review summarizing adult-onset proximal SMA presentations. RESULTS Previously limited to cases of SMN1-related SMA type 4 (adult form), this group has now more than 15 different clinical conditions that have in common the symmetrical and progressive compromise of lower motor neurons starting in adulthood or elderly stage. New clinical and genetic subtypes of adult-onset proximal SMA have been recognized and are currently target of wide neuroradiological, pathological, and genetic studies. CONCLUSIONS This new complex group of rare disorders typically present with lower motor neuron disease in association with other neurological or systemic signs of impairment, which are relatively specific and typical for each genetic subtype.
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Affiliation(s)
| | - Paulo Victor Sgobbi de Souza
- Universidade Federal de São Paulo, Departamento de Neurologia e Neurocirurgia, Setor de Investigações nas Doenças Neuromusculares, São Paulo SP, Brazil
| | - Bruno Mattos Lombardi Badia
- Universidade Federal de São Paulo, Departamento de Neurologia e Neurocirurgia, Setor de Investigações nas Doenças Neuromusculares, São Paulo SP, Brazil
| | - Igor Braga Farias
- Universidade Federal de São Paulo, Departamento de Neurologia e Neurocirurgia, Setor de Investigações nas Doenças Neuromusculares, São Paulo SP, Brazil
| | | | - Eduardo Augusto Gonçalves
- Universidade Federal de São Paulo, Departamento de Neurologia e Neurocirurgia, Setor de Investigações nas Doenças Neuromusculares, São Paulo SP, Brazil
| | - Roberta Ismael Lacerda Machado
- Universidade Federal de São Paulo, Departamento de Neurologia e Neurocirurgia, Setor de Investigações nas Doenças Neuromusculares, São Paulo SP, Brazil
| | - Acary Souza Bulle Oliveira
- Universidade Federal de São Paulo, Departamento de Neurologia e Neurocirurgia, Setor de Investigações nas Doenças Neuromusculares, São Paulo SP, Brazil
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Jin C, Yonezawa A. Recent advances in riboflavin transporter RFVT and its genetic disease. Pharmacol Ther 2021; 233:108023. [PMID: 34662687 DOI: 10.1016/j.pharmthera.2021.108023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/30/2021] [Accepted: 10/12/2021] [Indexed: 12/20/2022]
Abstract
Riboflavin (vitamin B2) is essential for cellular growth and function. It is enzymatically converted to flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which participate in the metabolic oxidation-reduction reactions of carbohydrates, amino acids, and lipids. Human riboflavin transporters RFVT1, RFVT2, and RFVT3 have been identified and characterized since 2008. They are highly specific transporters of riboflavin. RFVT3 has functional characteristics different from those of RFVT1 and RFVT2. RFVT3 contributes to absorption in the small intestine, reabsorption in the kidney, and transport to the fetus in the placenta, while RFVT2 mediates the tissue distribution of riboflavin from the blood. Several mutations in the SLC52A2 gene encoding RFVT2 and the SLC52A3 gene encoding RFVT3 were found in patients with a rare neurological disorder known as Brown-Vialetto-Van Laere syndrome. These patients commonly present with bulbar palsy, hearing loss, muscle weakness, and respiratory symptoms in infancy or later in childhood. A decrease in plasma riboflavin levels has been observed in several cases. Recent studies on knockout mice and patient-derived cells have advanced the understanding of these mechanisms. Here, we summarize novel findings on RFVT1-3 and their genetic diseases and discuss their potential as therapeutic drugs.
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Affiliation(s)
- Congyun Jin
- Department of Clinical Pharmacology and Therapeutics, Kyoto University Hospital, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan; Graduate School of Pharmaceutical Sciences, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Atsushi Yonezawa
- Department of Clinical Pharmacology and Therapeutics, Kyoto University Hospital, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan; Graduate School of Pharmaceutical Sciences, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
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Plantone D, Pardini M, Rinaldi G. Riboflavin in Neurological Diseases: A Narrative Review. Clin Drug Investig 2021; 41:513-527. [PMID: 33886098 DOI: 10.1007/s40261-021-01038-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2021] [Indexed: 12/11/2022]
Abstract
Riboflavin is classified as one of the water-soluble B vitamins. It is part of the functional group of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) cofactors and is required for numerous flavoprotein-catalysed reactions. Riboflavin has important antioxidant properties, essential for correct cell functioning. It is required for the conversion of oxidised glutathione to the reduced form and for the mitochondrial respiratory chain as complexes I and II contain flavoprotein reductases and electron transferring flavoproteins. Riboflavin deficiency has been demonstrated to impair the oxidative state of the body, especially in relation to lipid peroxidation status, in both animal and human studies. In the nervous system, riboflavin is essential for the synthesis of myelin and its deficiency can determine the disruption of myelin lamellae. The inherited condition of restricted riboflavin absorption and utilisation, reported in about 10-15% of world population, warrants further investigation in relation to its association with the main neurodegenerative diseases. Several successful trials testing riboflavin for migraine prevention were performed, and this drug is currently classified as a Level B medication for migraine according to the American Academy of Neurology evidence-based rating, with evidence supporting its efficacy. Brown-Vialetto-Van Laere syndrome and Fazio-Londe diseases are now renamed as "riboflavin transporter deficiency" because these are autosomal recessive diseases caused by mutations of SLC52A2 and SLC52A3 genes that encode riboflavin transporters. High doses of riboflavin represent the mainstay of the therapy of these diseases and high doses of riboflavin should be rapidly started as soon as the diagnosis is suspected and continued lifelong. Remarkably, some mitochondrial diseases respond to supplementation with riboflavin. These include multiple acyl-CoA-dehydrogenase deficiency (which is caused by ETFDH gene mutations in the majority of the cases, or mutations in the ETFA and ETFB genes in a minority), mutations of ACAD9 gene, mutations of AIFM1 gene, mutations of the NDUFV1 and NDUFV2 genes. Therapeutic riboflavin administration has been tried in other neurological diseases, including stroke, multiple sclerosis, Friedreich's ataxia and Parkinson's disease. Unfortunately, the design of these clinical trials was not uniform, not allowing to accurately assess the real effects of this molecule on the disease course. In this review we analyse the properties of riboflavin and its possible effects on the pathogenesis of different neurological diseases, and we will review the current indications of this vitamin as a therapeutic intervention in neurology.
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Affiliation(s)
- Domenico Plantone
- Neurology Unit, Azienda Sanitaria Locale della Provincia di Bari, Di Venere Teaching Hospital, Via Ospedale Di Venere 1, 70131, Bari, Italy.
| | - Matteo Pardini
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy.,Ospedale Policlinico San Martino, IRCCS, Genoa, Italy
| | - Giuseppe Rinaldi
- Neurology Unit, Azienda Sanitaria Locale della Provincia di Bari, Di Venere Teaching Hospital, Via Ospedale Di Venere 1, 70131, Bari, Italy
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Gayathri S, Gowda VK, Udhayabanu T, O'Callaghan B, Efthymiou S, Varalakshmi P, Benakappa N, Houlden H, Ashokkumar B. Brown-Vialetto-Van Laere and Fazio-Londe syndromes: SLC52A3 mutations with puzzling phenotypes and inheritance. Eur J Neurol 2021; 28:945-954. [PMID: 33325104 DOI: 10.1111/ene.14682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/19/2020] [Accepted: 12/10/2020] [Indexed: 12/01/2022]
Abstract
BACKGROUND Brown-Vialetto-Van Laere syndrome (BVVLS) and Fazio-Londe disease (FLD) are rare neurological disorders presenting with pontobulbar palsy, muscle weakness and respiratory insufficiency. Mutations in SLC52A2 (hRFVT-2) or SLC52A3 (hRFVT-3) genes can be responsible for these disorders with an autosomal recessive pattern of inheritance. The aim of this study was to screen for mutations in SLC52A2 and SLC52A3 among Indian families diagnosed with BVVLS and FLD. METHODS SLC52A2 and SLC52A3 were screened in one FLD and three BVVLS patients by exon-specific amplification using PCR and sequencing. In silico predictions using bioinformatics tools and confocal imaging using HEK-293 cells were performed to determine the functional impact of identified mutations. RESULTS Genetic analysis of a mother and son with BVVLS was identified with a novel homozygous mutation c.710C>T (p.Ala237Val) in SLC52A3. This variant was found to have an autosomal pseudodominant pattern of inheritance, which was neither listed in the Exome Variant Server or in the 1000 Genomes Project database. In silico analysis and confocal imaging of the p.Ala237Val variant showed higher degree of disorderness in hRFVT-3 that could affect riboflavin transport. Furthermore, a common homozygous mutation c.62A>G (p.Asn21Ser) was identified in other BVVLS and FLD patients. Despite having different clinical phenotypes, both BVVLS and FLD can be attributed to this mutation. CONCLUSION A rare and peculiar pattern of autosomal pseudodominant inheritance is observed for the first time in two genetically related BVVLS cases with Indian origin and a common mutation c.62A>G (p.Asn21Ser) in SLC52A3 can be responsible for both BVVLS and FLD with variable phenotypes.
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Affiliation(s)
| | - Vykuntaraju K Gowda
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, India
| | | | - Benjamin O'Callaghan
- Department of Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | - Stephanie Efthymiou
- Department of Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | | | - Naveen Benakappa
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, India
| | - Henry Houlden
- Department of Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
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8
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Effect of riboflavin deficiency on development of the cerebral cortex in Slc52a3 knockout mice. Sci Rep 2020; 10:18443. [PMID: 33116204 PMCID: PMC7595085 DOI: 10.1038/s41598-020-75601-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 10/19/2020] [Indexed: 12/13/2022] Open
Abstract
Riboflavin transporter 3 (RFVT3), encoded by the SLC52A3 gene, is important for riboflavin homeostasis in the small intestine, kidney, and placenta. Our previous study demonstrated that Slc52a3 knockout (Slc52a3−/−) mice exhibited neonatal lethality and metabolic disorder due to riboflavin deficiency. Here, we investigated the influence of Slc52a3 gene disruption on brain development using Slc52a3−/− embryos. Slc52a3−/− mice at postnatal day 0 showed hypoplasia of the brain and reduced thickness of cortical layers. At embryonic day 13.5, the formation of Tuj1+ neurons and Tbr2+ intermediate neural progenitors was significantly decreased; no significant difference was observed in the total number and proliferative rate of Pax6+ radial glia. Importantly, the hypoplastic phenotype was rescued upon riboflavin supplementation. Thus, it can be concluded that RFVT3 contributes to riboflavin homeostasis in embryos and that riboflavin itself is required during embryonic development of the cerebral cortex in mice.
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Carreau C, Benoit C, Ahle G, Cauquil C, Roubertie A, Lenglet T, Cosgrove J, Meunier I, Veauville-Merllié A, Acquaviva-Bourdain C, Nadjar Y. Late-onset riboflavin transporter deficiency: a treatable mimic of various motor neuropathy aetiologies. J Neurol Neurosurg Psychiatry 2020; 92:jnnp-2020-323304. [PMID: 33087424 DOI: 10.1136/jnnp-2020-323304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/27/2020] [Accepted: 08/18/2020] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Riboflavin transporter deficiencies (RTDs), involving SLC52A3 and SLC52A2 genes, have recently been related to Brown-Vialetto-Van Laere (BVVL) syndrome, a hereditary paediatric condition associating motor neuropathy (MN) and deafness. BVVL/RTD has rarely been reported in adult patients, but is probably underdiagnosed due to poor knowledge and lack of awareness of this form of disease among neurologists. In this study, we aimed to investigate the phenotype and prognosis of RTD patients with late-onset MN. METHODS We retrospectively collected clinical, biological and electrophysiological data from all French RTD patients with MN onset after 10 years of age (n=6) and extracted data from 19 other similar RTD patients from the literature. RESULTS Adult RTD patients with MN had heterogeneous clinical presentations, potentially mimicking amyotrophic lateral sclerosis or distal hereditary motor neuropathy (56%), multinevritis with cranial nerve involvement (16%), Guillain-Barré syndrome (8%) and mixed motor and sensory neuronopathy syndromes (20%, only in SLC52A2 patients). Deafness was often diagnosed before MN (in 44%), but in some patients, onset began only with MN (16%). The pattern of weakness varied widely, and the classic pontobulbar palsy described in BVVL was not constant. Biochemical tests were often normal. The majority of patients improved under riboflavin supplementation (86%). INTERPRETATION Whereas late-onset RTD may mimic different acquired or genetic causes of motor neuropathies, it is a diagnosis not to be missed since high-dose riboflavin per oral supplementation is often highly efficient.
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Affiliation(s)
- Christophe Carreau
- Department of Neurology, Reference Center for Lysosomal Diseases, Neuro-Metabolism Unit, AP-HP, Hôpital Universitaire Pitié Salpêtrière, Paris, France
| | - Charline Benoit
- Department of Neurology, AP-HP, Hôpital Universitaire Pitié Salpêtrière, Paris, France
| | - Guido Ahle
- Neurology, Hôpital Louis Pasteur, Colmar, Alsace, France
| | - Cécile Cauquil
- Neurology, Hôpital Bicêtre, Le Kremlin-Bicêtre, Île-de-France, France
| | - Agathe Roubertie
- Neuropediatrie, Hôpital Gui de Chauliac Pôle Neurosciences tête et cou, Montpellier, Languedoc-Roussillon Midi, France
| | - Timothée Lenglet
- Department of Neurophysiology, AP-HP, Hôpital Universitaire Pitié Salpêtrière, Paris, France
| | | | - Isabelle Meunier
- Ophthalmology, Hôpital Gui de Chauliac, Montpellier, Languedoc-Roussillon, France
| | - Alice Veauville-Merllié
- Laboratory of Inborn Errors of Metabolism, Hospices Civils de Lyon, Lyon, Auvergne-Rhône-Alpes, France
| | - Cécile Acquaviva-Bourdain
- Laboratory of Inborn Errors of Metabolism, Hospices Civils de Lyon, Lyon, Auvergne-Rhône-Alpes, France
| | - Yann Nadjar
- Department of Neurology, Reference Center for Lysosomal Diseases, Neuro-Metabolism Unit, AP-HP, Hôpital Universitaire Pitié Salpêtrière, Paris, France
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Sinha T, Naash MI, Al-Ubaidi MR. Flavins Act as a Critical Liaison Between Metabolic Homeostasis and Oxidative Stress in the Retina. Front Cell Dev Biol 2020; 8:861. [PMID: 32984341 PMCID: PMC7481326 DOI: 10.3389/fcell.2020.00861] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 08/10/2020] [Indexed: 12/14/2022] Open
Abstract
Derivatives of the vitamin riboflavin, FAD and FMN, are essential cofactors in a multitude of bio-energetic reactions, indispensable for lipid metabolism and also are requisites in mitigating oxidative stress. Given that a balance between all these processes contributes to the maintenance of retinal homeostasis, effective regulation of riboflavin levels in the retina is paramount. However, various genetic and dietary factors have brought to fore pathological conditions that co-occur with a suboptimal level of flavins in the retina. Our focus in this review is to, comprehensively summarize all the possible metabolic and oxidative reactions which have been implicated in various retinal pathologies and to highlight the contribution flavins may have played in these. Recent research has found a sensitive method of measuring flavins in both diseased and healthy retina, presence of a novel flavin binding protein exclusively expressed in the retina, and the presence of flavin specific transporters in both the inner and outer blood-retina barriers. In light of these exciting findings, it is even more imperative to shift our focus on how the retina regulates its flavin homeostasis and what happens when this is disrupted.
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Affiliation(s)
- Tirthankar Sinha
- Department of Biomedical Engineering, University of Houston, Houston, TX, United States
| | - Muna I Naash
- Department of Biomedical Engineering, University of Houston, Houston, TX, United States
| | - Muayyad R Al-Ubaidi
- Department of Biomedical Engineering, University of Houston, Houston, TX, United States
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11
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O'Callaghan B, Bosch AM, Houlden H. An update on the genetics, clinical presentation, and pathomechanisms of human riboflavin transporter deficiency. J Inherit Metab Dis 2019; 42:598-607. [PMID: 30793323 DOI: 10.1002/jimd.12053] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 12/31/2018] [Indexed: 11/10/2022]
Abstract
Riboflavin transporter deficiency (RTD) is a rare neurological condition that encompasses the Brown-Vialetto-Van Laere and Fazio-Londe syndromes since the discovery of pathogenic mutations in the SLC52A2 and SLC52A3 genes that encode human riboflavin transporters RFVT2 and RFVT3. Patients present with a deteriorating progression of peripheral and cranial neuropathy that causes muscle weakness, vision loss, deafness, sensory ataxia, and respiratory compromise which when left untreated can be fatal. Considerable progress in the clinical and genetic diagnosis of RTDs has been made in recent years and has permitted the successful lifesaving treatment of many patients with high dose riboflavin supplementation. In this review, we first outline the importance of riboflavin and its efficient transmembrane transport in human physiology. Reports on 109 patients with a genetically confirmed diagnosis of RTD are then summarized in order to highlight commonly presenting clinical features and possible differences between patients with pathogenic SLC52A2 (RTD2) or SLC52A3 (RTD3) mutations. Finally, we focus attention on recent work with different models of RTD that have revealed possible pathomechanisms contributing to neurodegeneration in patients.
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Affiliation(s)
- Benjamin O'Callaghan
- MRC Centre for Neuromuscular Diseases, Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Annet M Bosch
- Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Pediatric Metabolic Diseases, Amsterdam, The Netherlands
| | - Henry Houlden
- MRC Centre for Neuromuscular Diseases, Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
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