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Abstract
BACKGROUND To describe the clinical presentation with a focus on ocular manifestations and response to riboflavin supplementation of 3 patients with riboflavin transporter deficiency (RTD) caused by mutations in SLC52A2 ( SLC52A2- RTD). METHODS This is a retrospective review of records of 3 children (aged 18, n = 2 and age = 8, n = 1) with SLC52A2- RTD. Patients underwent comprehensive ophthalmic evaluations including color vision testing, pattern visual-evoked potentials (pVEPs, 1 patient) and spectral domain optical coherence tomography (SD-OCT) imaging. Patients received riboflavin supplements from the time of the molecular diagnosis of RTD. RESULTS Two unrelated 18-year-old patients with SLC52A2- RTD had a symptomatic onset with sensorineural hearing loss and auditory neuropathy/dys-synchrony since age 3 and 11, respectively. On examination 7 years after symptomatic onset, they showed subnormal visual acuities (20/30 and 20/60, both eyes, respectively), preserved color vision, and a thin but measurable retinal ganglion cell layer (GCL) and nerve fiber (RNFL). The inner and outer nuclear layers were normal. The asymptomatic SLC52A2- positive brother of one of these patients started riboflavin supplementation right after the molecular diagnosis and had normal vision and SD-OCTs 7 years later. Onset of riboflavin supplementation in one of the 2 symptomatic cases resulted in acute improvement of the pattern visual-evoked potential and vision. CONCLUSIONS Retinal ganglion cells and their axons are uniquely susceptible to RTD compared with other highly energy-dependent retinal neurons, such as photoreceptors, raising the possibility for alternative mechanisms of disease or protection. Riboflavin supplementation results in acute functional improvement of vision and long-term preservation of GCL and RNFL if initiated early.
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Amir F, Atzinger C, Massey K, Greinwald J, Hunter LL, Ulm E, Kettler M. The Clinical Journey of Patients with Riboflavin Transporter Deficiency Type 2. J Child Neurol 2020; 35:283-290. [PMID: 31868069 DOI: 10.1177/0883073819893159] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PURPOSE To identify symptoms and health care interactions with patients with riboflavin transporter deficiency (RTD) type 2 prior to diagnosis. METHODS Parents of children with riboflavin transporter deficiency type 2 (n = 10) were interviewed to collect data on the patient's clinical journey. RESULTS The average diagnostic delay was 27.6 months. Neurologists were the most commonly visited clinician (90%). Common symptoms during the first year of the patient's clinical journey included abnormal gait and/or ataxia (70%), nystagmus (50%), and upper body muscle weakness (40%). Prior to diagnosis, optic atrophy, sleep apnea, breath-holding spells, and dysphagia were commonly observed. Hearing loss was only reported in 40% of subjects prior to diagnosis. Riboflavin responsive megaloblastic anemia is reported for the first time. Mitochondrial disease was the most common suspected diagnosis (30%). CONCLUSION Despite clinical variability, common early symptoms of riboflavin transporter deficiency type 2 exist that can better allow clinicians to more rapidly identify riboflavin transporter deficiency type 2.
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Affiliation(s)
- Fatima Amir
- College of Medicine, University of Cincinnati, Cincinnati, OH, USA.,Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Carrie Atzinger
- College of Medicine, University of Cincinnati, Cincinnati, OH, USA.,Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | | | - John Greinwald
- Division of Pediatric Otolaryngology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Lisa L Hunter
- Cincinnati Children's Hospital Medical Center, Center for Professional Excel Rsch & EBP, Cincinnati, OH, USA
| | - Elizabeth Ulm
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Margaret Kettler
- Division of Audiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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Bamaga AK, Maamari RN, Culican SM, Shinawi M, Golumbek PT. Child Neurology: Brown-Vialetto-Van Laere syndrome: Dramatic visual recovery after delayed riboflavin therapy. Neurology 2019; 91:938-941. [PMID: 30420458 DOI: 10.1212/wnl.0000000000006498] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Ahmed K Bamaga
- From the Departments of Neurology (A.K.B., P.T.G.) and Ophthalmology and Visual Sciences (R.N.M., S.M.C.) and Division of Genetics and Genomic Medicine, Department of Pediatrics (M.S.), Washington University School of Medicine, St Louis, MO; and Department of Pediatrics (A.K.B.), King Abdulaziz University, Jeddah, Saudi Arabia.
| | - Robi N Maamari
- From the Departments of Neurology (A.K.B., P.T.G.) and Ophthalmology and Visual Sciences (R.N.M., S.M.C.) and Division of Genetics and Genomic Medicine, Department of Pediatrics (M.S.), Washington University School of Medicine, St Louis, MO; and Department of Pediatrics (A.K.B.), King Abdulaziz University, Jeddah, Saudi Arabia
| | - Susan M Culican
- From the Departments of Neurology (A.K.B., P.T.G.) and Ophthalmology and Visual Sciences (R.N.M., S.M.C.) and Division of Genetics and Genomic Medicine, Department of Pediatrics (M.S.), Washington University School of Medicine, St Louis, MO; and Department of Pediatrics (A.K.B.), King Abdulaziz University, Jeddah, Saudi Arabia
| | - Marwan Shinawi
- From the Departments of Neurology (A.K.B., P.T.G.) and Ophthalmology and Visual Sciences (R.N.M., S.M.C.) and Division of Genetics and Genomic Medicine, Department of Pediatrics (M.S.), Washington University School of Medicine, St Louis, MO; and Department of Pediatrics (A.K.B.), King Abdulaziz University, Jeddah, Saudi Arabia
| | - Paul T Golumbek
- From the Departments of Neurology (A.K.B., P.T.G.) and Ophthalmology and Visual Sciences (R.N.M., S.M.C.) and Division of Genetics and Genomic Medicine, Department of Pediatrics (M.S.), Washington University School of Medicine, St Louis, MO; and Department of Pediatrics (A.K.B.), King Abdulaziz University, Jeddah, Saudi Arabia
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Anderson P, Schaefer S, Henderson L, Bruce IA. Cochlear implantation in children with auditory neuropathy: Lessons from Brown–Vialetto–Van Laere syndrome. Cochlear Implants Int 2018; 20:31-38. [DOI: 10.1080/14670100.2018.1534035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Phoebe Anderson
- Manchester Medical School, University of Manchester, Manchester, UK
| | - Simone Schaefer
- Paediatric ENT Department, Royal Manchester Children’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - Lise Henderson
- Richard Ramsden Centre for Auditory Implants, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - Iain A. Bruce
- Paediatric ENT Department, Royal Manchester Children’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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Babanejad M, Adeli OA, Nikzat N, Beheshtian M, Azarafra H, Sadeghnia F, Mohseni M, Najmabadi H, Kahrizi K. SLC52A2 mutations cause SCABD2 phenotype: A second report. Int J Pediatr Otorhinolaryngol 2018; 104:195-199. [PMID: 29287867 DOI: 10.1016/j.ijporl.2017.11.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 11/15/2017] [Accepted: 11/15/2017] [Indexed: 01/21/2023]
Abstract
INTRODUCTION Autosomal recessive cerebellar ataxias (ARCAs) are a large group of neurodegenerative disorders that manifest mainly in children and young adults. Most ARCAs are heterogeneous with respect to age at onset, severity of disease progression, and frequency of extracerebellar and systemic signs. METHODS The phenotype of a consanguineous Iranian family was characterized using clinical testing and pedigree analysis. Whole-exome sequencing was used to identify the disease-causing gene in this family. RESULTS AND CONCLUSION Using whole exome sequencing (WES), a novel missense mutation in SLC52A2 gene is reported in a consanguineous Iranian family with progressive severe hearing loss, optic atrophy and ataxia. This is the second report of the genotype-phenotype correlation between this syndrome named spinocerebellar ataxia with blindness and deafness type 2 (SCABD2) and SLC52A2 gene.
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Affiliation(s)
- Mojgan Babanejad
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Omid Ali Adeli
- Lorestan University of Medical Sciences, Khorramabad, Lorestan, Iran
| | - Nooshin Nikzat
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Maryam Beheshtian
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Hakimeh Azarafra
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Farnaz Sadeghnia
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Marzieh Mohseni
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Hossein Najmabadi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Kimia Kahrizi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
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Thulasi V, Veerapandiyan A, Pletcher BA, Tong CM, Ming X. A Case of Brown-Vialetto-Van Laere Syndrome Due To a Novel Mutation in SLC52A3 Gene: Clinical Course and Response to Riboflavin. Child Neurol Open 2017; 4:2329048X17725610. [PMID: 28856173 PMCID: PMC5570109 DOI: 10.1177/2329048x17725610] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 05/30/2017] [Accepted: 06/23/2017] [Indexed: 11/15/2022] Open
Abstract
Brown-Vialetto-Van Laere syndrome is a rare disorder characterized by motor, sensory, and cranial neuronopathies, associated with mutations in SLC52A2 and SLC52A3 genes that code for human riboflavin transporters RFVT2 and RFVT3, respectively. The authors describe the clinical course of a 6-year-old girl with Brown-Vialetto-Van Laere syndrome and a novel homozygous mutation c.1156T>C in the SLC52A3 gene, who presented at the age of 2.5 years with progressive brain stem dysfunction including ptosis, facial weakness, hearing loss, dysphagia, anarthria with bilateral vocal cord paralysis, and ataxic gait. She subsequently developed respiratory failure requiring tracheostomy and worsening dysphagia necessitating a gastrostomy. Following riboflavin supplementation, resolution of facial diplegia and ataxia, improvements in ptosis, and bulbar function including vocalization and respiration were noted. However, her sensorineural hearing loss remained unchanged. Similar to other cases of Brown-Vialetto-Van Laere syndrome, our patient responded favorably to early riboflavin supplementation with significant but not complete neurologic recovery.
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Affiliation(s)
- Venkatraman Thulasi
- Division of Pediatric Neurology, Department of Neurology, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Aravindhan Veerapandiyan
- Division of Pediatric Neurology, Department of Neurology, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Beth A Pletcher
- Division of Clinical Genetics, Department of Pediatrics, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Chun M Tong
- Division of Pediatric Neurology, Department of Neurology, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Xue Ming
- Division of Pediatric Neurology, Department of Neurology, Rutgers New Jersey Medical School, Newark, NJ, USA
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Need AC, Goldstein DB. Neuropsychiatric genomics in precision medicine: diagnostics, gene discovery, and translation. DIALOGUES IN CLINICAL NEUROSCIENCE 2017. [PMID: 27757059 PMCID: PMC5067142 DOI: 10.31887/dcns.2016.18.3/aneed] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Only a few years after its development, next-generation sequencing is rapidly becoming an essential part of clinical care for patients with serious neurological conditions, especially in the diagnosis of early-onset and severe presentations. Beyond this diagnostic role, there has been an explosion in definitive gene discovery in a range of neuropsychiatric diseases. This is providing new pointers to underlying disease biology and is beginning to outline a new framework for genetic stratification of neuropsychiatric disease, with clear relevance to both individual treatment optimization and clinical trial design. Here, we outline these developments and chart the expected impact on the treatment of neurological, neurodevelopmental, and psychiatric disease.
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Affiliation(s)
- Anna C Need
- Division of Brain Sciences, Department of Medicine, Imperial College London, London, W12 ONN, UK
| | - David B Goldstein
- Institute for Genomic Medicine, Columbia University, New York, NY, 10032, USA
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Smith M. DNA Sequence Analysis in Clinical Medicine, Proceeding Cautiously. Front Mol Biosci 2017; 4:24. [PMID: 28516087 PMCID: PMC5413496 DOI: 10.3389/fmolb.2017.00024] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 04/07/2017] [Indexed: 12/03/2022] Open
Abstract
Delineation of underlying genomic and genetic factors in a specific disease may be valuable in establishing a definitive diagnosis and may guide patient management and counseling. In addition, genetic information may be useful in identification of at risk family members. Gene mapping and initial genome sequencing data enabled the development of microarrays to analyze genomic variants. The goal of this review is to consider different generations of sequencing techniques and their application to exome sequencing and whole genome sequencing and their clinical applications. In recent decades, exome sequencing has primarily been used in patient studies. Discussed in some detail, are important measures that have been developed to standardize variant calling and to assess pathogenicity of variants. Examples of cases where exome sequencing has facilitated diagnosis and led to improved medical management are presented. Whole genome sequencing and its clinical relevance are presented particularly in the context of analysis of nucleotide and structural genomic variants in large population studies and in certain patient cohorts. Applications involving analysis of cell free DNA in maternal blood for prenatal diagnosis of specific autosomal trisomies are reviewed. Applications of DNA sequencing to diagnosis and therapeutics of cancer are presented. Also discussed are important recent diagnostic applications of DNA sequencing in cancer, including analysis of tumor derived cell free DNA and exosomes that are present in body fluids. Insights gained into underlying pathogenetic mechanisms of certain complex common diseases, including schizophrenia, macular degeneration, neurodegenerative disease are presented. The relevance of different types of variants, rare, uncommon, and common to disease pathogenesis, and the continuum of causality, are addressed. Pharmogenetic variants detected by DNA sequence analysis are gaining in importance and are particularly relevant to personalized and precision medicine.
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Affiliation(s)
- Moyra Smith
- Genetics and Genomic Medicine, Pediatrics, School of Medicine, University of CaliforniaIrvine, CA, USA
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Need AC. Neuropsychiatric genomics in precision medicine: diagnostics, gene discovery, and translation. DIALOGUES IN CLINICAL NEUROSCIENCE 2016; 18:237-252. [PMID: 27757059 PMCID: PMC5067142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Only a few years after its development, next-generation sequencing is rapidly becoming an essential part of clinical care for patients with serious neurological conditions, especially in the diagnosis of early-onset and severe presentations. Beyond this diagnostic role, there has been an explosion in definitive gene discovery in a range of neuropsychiatric diseases. This is providing new pointers to underlying disease biology and is beginning to outline a new framework for genetic stratification of neuropsychiatric disease, with clear relevance to both individual treatment optimization and clinical trial design. Here, we outline these developments and chart the expected impact on the treatment of neurological, neurodevelopmental, and psychiatric disease.
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Affiliation(s)
- Anna C. Need
- Division of Brain Sciences, Department of Medicine, Imperial College London, London, W12 ONN, UK
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Not the End of the Odyssey: Parental Perceptions of Whole Exome Sequencing (WES) in Pediatric Undiagnosed Disorders. J Genet Couns 2016; 25:1019-31. [PMID: 26868367 DOI: 10.1007/s10897-016-9933-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 01/14/2016] [Indexed: 01/26/2023]
Abstract
Due to the lack of empirical information on parental perceptions of primary results of whole exome sequencing (WES), we conducted a retrospective semi-structured interview with 19 parents of children who had undergone WES. Perceptions explored during the interview included factors that would contribute to parental empowerment such as: parental expectations, understanding of the WES and results, utilization of the WES information, and communication of findings to health/educational professionals and family members. Results of the WES had previously been communicated to families within a novel framework of clinical diagnostic categories: 5/19 had Definite diagnoses, 6/19 had Likely diagnoses, 3/19 had Possible diagnosis and 5/19 had No diagnosis. All parents interviewed expressed a sense of duty to pursue the WES in search of a diagnosis; however, their expectations were tempered by previous experiences with negative genetic testing results. Approximately half the parents worried that a primary diagnosis that would be lethal might be identified; however, the hope of a diagnosis outweighed this concern. Parents were accurately able to summarize their child's WES findings, understood the implications for recurrence risks, and were able to communicate these findings to family and medical/educational providers. The majority of those with a Definite/Likely diagnosis felt that their child's medical care was more focused, or there was a reduction in worry, despite the lack of a specific treatment. Irrespective of diagnostic outcome, parents recommended that follow-up visits be built into the process. Several parents expressed a desire to have all variants of unknown significance (VUS) reported to them so that they could investigate these themselves. Finally, for some families whose children had a Definite/Likely diagnosis, there was remaining frustration and a sense of isolation, due to the limited information that was available about the diagnosed rare disorders and the inability to connect to other families, suggesting that for families with rare genetic disorders, the diagnostic odyssey does not necessarily end with a diagnosis. Qualitative interviewing served a meaningful role in eliciting new information about parental motivations, expectations, and knowledge of WES. Our findings highlight a need for continued communication with families as we navigate the new landscape of genomic sequencing.
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