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Dobloug S, Kjellström U, Anderson G, Gardner E, Mole SE, Sheth J, Puschmann A. Maculopathy and adult-onset ataxia in patients with biallelic MFSD8 variants. Mol Genet Genomic Med 2024; 12:e2505. [PMID: 39108195 PMCID: PMC11303817 DOI: 10.1002/mgg3.2505] [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: 05/16/2024] [Revised: 07/17/2024] [Accepted: 07/24/2024] [Indexed: 08/10/2024] Open
Abstract
BACKGROUND Biallelic variants in the major facilitator superfamily domain containing 8 gene (MFSD8) are associated with distinct clinical presentations that range from typical late-infantile neuronal ceroid lipofuscinosis type 7 (CLN7 disease) to isolated adult-onset retinal dystrophy. Classic late-infantile CLN7 disease is a severe, rare neurological disorder with an age of onset typically between 2 and 6 years, presenting with seizures and/or cognitive regression. Its clinical course is progressive, leading to premature death, and often includes visual loss due to severe retinal dystrophy. In rare cases, pathogenic variants in MFSD8 can be associated with isolated non-syndromic macular dystrophy with variable age at onset, in which the disease process predominantly or exclusively affects the cones of the macula and where there are no neurological or neuropsychiatric manifestations. METHODS Here we present longitudinal studies on four adult-onset patients who were biallelic for four MFSD8 variants. RESULTS Two unrelated patients who presented with adult-onset ataxia and had macular dystrophy on examination were homozygous for a novel variant in MFSD8 NM_152778.4: c.935T>C p.(Ile312Thr). Two other patients presented in adulthood with visual symptoms, and one of these developed mild to moderate cerebellar ataxia years after the onset of visual symptoms. CONCLUSIONS Our observations expand the knowledge on biallelic pathogenic MFSD8 variants and confirm that these are associated with a spectrum of more heterogeneous clinical phenotypes. In MFSD8-related disease, adult-onset recessive ataxia can be the presenting manifestation or may occur in combination with retinal dystrophy.
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Affiliation(s)
- Sigurd Dobloug
- Department of NeurologyHelsingborg General HospitalHelsingborgSweden
- Department for Clinical Sciences, Lund, NeurologyLund UniversityLundSweden
| | | | - Glenn Anderson
- Department of HistopathologyGreat Ormond Street HospitalLondonUK
| | - Emily Gardner
- Great Ormond Street Institute of Child HealthUniversity College LondonLondonUK
| | - Sara E. Mole
- Great Ormond Street Institute of Child HealthUniversity College LondonLondonUK
| | - Jayesh Sheth
- Foundation for Research in Genetics and EndocrinologyInstitute of Human GeneticsAhmedabadIndia
| | - Andreas Puschmann
- Lund University, Skåne University Hospital, NeurologyLundSweden
- SciLifeLabLund UniversityLundSweden
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2
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Kayani S, Edgar VB, Lowden A, Nettesheim ER, Dahshi H, Messahel S, Minassian BA, Greenberg BM. Neuronal Ceroid Lipofuscinoses Type 7 (CLN7)- A Case Series Reporting Cross Sectional and Retrospective Clinical Data to Evaluate Validity of Standardized Tools to Assess Disease Progression, Quality of Life, and Adaptive Skills. RESEARCH SQUARE 2024:rs.3.rs-3983366. [PMID: 38978590 PMCID: PMC11230482 DOI: 10.21203/rs.3.rs-3983366/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Background This study evaluated the clinical characteristics of neuronal ceroid lipofuscinosis type 7 or CLN7 disease spectrum to characterize the clinical, electrophysiologic and neuroimaging phenotypes. Methods We performed a single-center cross sectional data collection along with retrospective medical chart review in patients with a genetic diagnosis of CLN7. This study received ethical approval by the University of Texas Southwestern Medical Center Institutional Review Board. A total of 8 patients were included between the ages of 4 to 6 years. All patients had a genetic diagnosis of CLN7 with homozygous or compound heterozygous mutations in the MFSD8 gene. The information collected includes patient demographics, developmental history, neurological events including seizures and neurodevelopmental regression along with further evaluation of brain magnetic resonance imaging and electrophysiological findings. The clinical phenotype is described through cross sectional and retrospective data collection and standardized tools assessing quality of life and functional skills. Conclusions Our findings in this cohort of CLN7 patients indicated that development is initially normal with onset of clinical symptoms as early as two years of age. Language problems were noted prior to or at the onset of seizures in all cases. Gait problems were noted prior to seizure onset in 3 of 8 patients, and at or within 6 months after the onset of seizures in 5 of 8 patients. All patients followed a progressive course of language, motor, and neurocognitive deterioration. Congruent with the medical history, our patients had significantly low scores on adaptive abilities. Natural history data such as this can be used to support future clinical trial designs.
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Affiliation(s)
- Saima Kayani
- UT Southwestern: The University of Texas Southwestern Medical Center
| | | | - Andrea Lowden
- UT Southwestern: The University of Texas Southwestern Medical Center
| | | | - Hamza Dahshi
- UT Southwestern: The University of Texas Southwestern Medical Center
| | - Souad Messahel
- UT Southwestern: The University of Texas Southwestern Medical Center
| | - Berge A Minassian
- UT Southwestern: The University of Texas Southwestern Medical Center
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3
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Beckman M, Clevenger L, DeBenedictis MJ, Yuan A, Sharma S. A novel ocular phenotype associated with pathogenic variants in MFSD8 leading to macular dystrophy. Ophthalmic Genet 2023; 44:606-609. [PMID: 36861499 DOI: 10.1080/13816810.2023.2183224] [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: 11/07/2022] [Revised: 02/02/2023] [Accepted: 02/16/2023] [Indexed: 03/03/2023]
Abstract
BACKGROUND The major facilitator superfamily domain-containing protein 8 (MFSD8) pathogenic variants are classically associated with autosomal recessive neuronal ceroid lipofuscinosis-7. Case reports have recently demonstrated an association of MFSD8 variants causing autosomal recessive macular dystrophy with central cone involvement without neurologic sequelae. We report a patient with a novel ocular phenotype associated with MFSD8 pathogenic variants causing macular dystrophy without systemic findings. CASE PRESENTATION A 37-year-old female presented with a 20-year history of progressive bilateral vision loss. Fundus examination was notable for a slight pigmentary ring around the fovea in both eyes. Optical coherence tomography (OCT) of the macula showed bilateral subfoveal ellipsoid zone loss without outer retinal changes. Fundus autofluorescence (FAF) demonstrated foveal hypo-autofluorescence (AF) in both eyes as well as hyper-AF nasally to the optic nerve in the perifoveal area. Full-field and multifocal electroretinography demonstrated cone dysfunction with diffuse macular changes in both eyes. Subsequent genetic testing identified two pathogenic MFSD8 variants. The patient had no neurologic symptoms consistent with variant-late infantile neuronal ceroid lipofuscinosis. CONCLUSION MFSD8 pathogenic variants are known to cause macular dystrophies. We report a novel MFSD8-associated macular dystrophy phenotype demonstrating foveal-limited disease with cavitary changes on OCT without inner retinal atrophy and foveal-specific changes on FAF. A threshold model can explain how a hypomorphic missense variant heterozygous with a loss-of-function nonsense variant can lead to a predominantly ocular phenotype with preserved neurologic function. We recommend careful monitoring of these patients for future signs of both retinal and systemic disease progression.
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Affiliation(s)
- Madeline Beckman
- School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | | | | | - Alex Yuan
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Sumit Sharma
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA
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Priluck AZ, Breazzano MP. Novel MFSD8 mutation causing non-syndromic asymmetric adult-onset macular dystrophy. Ophthalmic Genet 2023; 44:186-190. [PMID: 35801630 DOI: 10.1080/13816810.2022.2092758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND MFSD8 mutations can cause type 7 neuronal ceroid lipofuscinosis, a systemic disorder that includes vision loss; however, such mutations can also cause isolated retinal dystrophy with vision loss without systemic signs or symptoms as first identified in 2015. This report details a previously unreported combination of compound heterozygous variants in the MFSD8 gene causing a non-syndromic, bilateral central macular dystrophy presenting in adulthood. MATERIALS AND METHODS We present a case of MFSD8-associated retinal dystrophy with multimodal imaging and a review of relevant literature. RESULTS A 57-year-old female presented for subacute, unilateral blurriness in her right eye. Best corrected visual acuity was 20/250 and 20/50 in the right and left eyes, respectively. Fundus examination and multimodal imaging revealed blunted foveal reflexes and optical gap with subfoveal ellipsoid zone loss in both eyes, right greater than left. Full field electroretinography results were within normal limits while the Arden ratio on electro-oculography was abnormal in both eyes, right more so than left. Genetic testing revealed apparently causative compound heterozygous mutations in the MFSD8 gene: c.154G>A, p.(Gly52Arg) and c.1006G>C, p.(Gluc336Gln). Visual acuity over one year of follow-up has remained stable. CONCLUSIONS To authors' knowledge, this report is first description of this combination of mutations in the MFSD8 gene leading to non-syndromic adult-onset macular dystrophy.
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Affiliation(s)
- Aaron Z Priluck
- Wilmer Eye Institute, Johns Hopkins Hospital, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mark P Breazzano
- Wilmer Eye Institute, Johns Hopkins Hospital, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Retina-Vitreous Surgeons of Central New York, Liverpool, NY, USA
- Department of Ophthalmology and Visual Sciences, State University of New York Upstate Medical University, Syracuse, NY, USA
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5
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Kolesnikova M, Lima de Carvalho JR, Oh JK, Soucy M, Demirkol A, Kim AH, Tsang SH, Breazzano MP. Phenotypic Variability of Retinal Disease Among a Cohort of Patients With Variants in the CLN Genes. Invest Ophthalmol Vis Sci 2023; 64:23. [PMID: 36912596 PMCID: PMC10019488 DOI: 10.1167/iovs.64.3.23] [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] [Indexed: 03/14/2023] Open
Abstract
Purpose To describe the phenotype of CLN-associated retinal dystrophy in a subset of patients at the Columbia University Medical Center, United States, and the Hospital das Clínicas de Pernambuco, Brazil, in comparison to the published literature. Methods Eleven patients with confirmed biallelic variants in the CLN genes were evaluated via dilated fundus examination, clinical imaging, and full-field electroretinogram. A thorough literature search was conducted to determine previously published variants and associated phenotypes. Results Genetic testing confirmed the presence of variants in CLN3, CLN7/MFSD8, CLN8, and GRN/CLN11. Five novel variants were identified, and four novel phenotypes of previously published alleles were described. The phenotype differed among patients with variants in the same gene and sometimes among patients with the same allele. Conclusions Substantial phenotypic variability among variants in the CLN genes makes identification of genotype-phenotype or allele-phenotype correlations challenging. Further study is required to establish an extensive database for adequate patient counseling.
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Affiliation(s)
- Masha Kolesnikova
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, New York-Presbyterian Hospital, New York, New York, United States.,College of Medicine at the State University of New York at Downstate Medical Center, Brooklyn, New York, United States
| | - Jose Ronaldo Lima de Carvalho
- Department of Ophthalmology, Hospital das Clínicas de Pernambuco, Empresa Brasileira de Serviços Hospitalares, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - Jin Kyun Oh
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Medical Center, New York-Presbyterian Hospital, New York, New York, United States
| | - Megan Soucy
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York, United States
| | - Aykut Demirkol
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, New York-Presbyterian Hospital, New York, New York, United States.,Usküdar University Vocational School of Health Services, Department of Opticianry, Istanbul, Turkey
| | - Angela H Kim
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, New York-Presbyterian Hospital, New York, New York, United States.,College of Medicine at the State University of New York at Downstate Medical Center, Brooklyn, New York, United States
| | - Stephen H Tsang
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, New York-Presbyterian Hospital, New York, New York, United States.,Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Medical Center, New York-Presbyterian Hospital, New York, New York, United States.,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York, United States
| | - Mark P Breazzano
- Wilmer Eye Institute, Johns Hopkins Hospital, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States.,Retina-Vitreous Surgeons of Central New York, Liverpool, New York, United States.,Department of Ophthalmology & Visual Sciences, State University of New York Upstate Medical University, Syracuse, New York, United States
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Linear Diagnostic Procedure Elicited by Clinical Genetics and Validated by mRNA Analysis in Neuronal Ceroid Lipofuscinosis 7 Associated with a Novel Non-Canonical Splice Site Variant in MFSD8. Genes (Basel) 2023; 14:genes14020245. [PMID: 36833170 PMCID: PMC9956376 DOI: 10.3390/genes14020245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/08/2023] [Accepted: 01/16/2023] [Indexed: 01/19/2023] Open
Abstract
Neuronal ceroid lipofuscinoses (CNL) are lysosomal storage diseases that represent the most common cause of dementia in children. To date, 13 autosomal recessive (AR) and 1 autosomal dominant (AD) gene have been characterized. Biallelic variants in MFSD8 cause CLN7 type, with nearly 50 pathogenic variants, mainly truncating and missense, reported so far. Splice site variants require functional validation. We detected a novel homozygous non-canonical splice-site variant in MFSD8 in a 5-year-old girl who presented with progressive neurocognitive impairment and microcephaly. The diagnostic procedure was elicited by clinical genetics first, and then confirmed by cDNA sequencing and brain imaging. Inferred by the common geographic origin of the parents, an autosomal recessive inheritance was hypothesized, and SNP-array was performed as the first-line genetic test. Only three AR genes lying within the observed 24 Mb regions of homozygosity were consistent with the clinical phenotype, including EXOSC9, SPATA5 and MFSD8. The cerebral and cerebellar atrophy detected in the meantime by MRI, along with the suspicion of accumulation of ceroid lipopigment in neurons, prompted us to perform targeted MFSD8 sequencing. Following the detection of a splice site variant of uncertain significance, skipping of exon 8 was demonstrated by cDNA sequencing, and the variant was redefined as pathogenic.
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7
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Poncet AF, Grunewald O, Vaclavik V, Meunier I, Drumare I, Pelletier V, Bocquet B, Todorova MG, Le Moing AG, Devos A, Schorderet DF, Jobic F, Defoort-Dhellemmes S, Dollfus H, Smirnov VM, Dhaenens CM. Contribution of Whole-Genome Sequencing and Transcript Analysis to Decipher Retinal Diseases Associated with MFSD8 Variants. Int J Mol Sci 2022; 23:ijms23084294. [PMID: 35457110 PMCID: PMC9032189 DOI: 10.3390/ijms23084294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 03/25/2022] [Accepted: 04/11/2022] [Indexed: 01/01/2023] Open
Abstract
Biallelic gene defects in MFSD8 are not only a cause of the late-infantile form of neuronal ceroid lipofuscinosis, but also of rare isolated retinal degeneration. We report clinical and genetic data of seven patients compound heterozygous or homozygous for variants in MFSD8, issued from a French cohort with inherited retinal degeneration, and two additional patients retrieved from a Swiss cohort. Next-generation sequencing of large panels combined with whole-genome sequencing allowed for the identification of twelve variants from which seven were novel. Among them were one deep intronic variant c.998+1669A>G, one large deletion encompassing exon 9 and 10, and a silent change c.750A>G. Transcript analysis performed on patients’ lymphoblastoid cell lines revealed the creation of a donor splice site by c.998+1669A>G, resulting in a 140 bp pseudoexon insertion in intron 10. Variant c.750A>G produced exon 8 skipping. In silico and in cellulo studies of these variants allowed us to assign the pathogenic effect, and showed that the combination of at least one severe variant with a moderate one leads to isolated retinal dystrophy, whereas the combination in trans of two severe variants is responsible for early onset severe retinal dystrophy in the context of late-infantile neuronal ceroid lipofuscinosis.
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Affiliation(s)
- Anaïs F. Poncet
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, F-59000 Lille, France; (A.F.P.); (O.G.); (A.D.)
| | - Olivier Grunewald
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, F-59000 Lille, France; (A.F.P.); (O.G.); (A.D.)
| | - Veronika Vaclavik
- University of Lausanne, Jules-Gonin Eye Hospital, 1004 Lausanne, Switzerland;
- Cantonal Hospital, Department of Ophthalmology, 1700 Fribourg, Switzerland
| | - Isabelle Meunier
- National Reference Centre for Inherited Sensory Diseases, University of Montpellier, Montpellier University Hospital, Sensgene Care Network, ERN-EYE Network, F-34000 Montpellier, France; (I.M.); (B.B.)
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, F-34000 Montpellier, France
| | - Isabelle Drumare
- Exploration de la Vision et Neuro-Ophtalmology, CHU de Lille, F-59000 Lille, France; (I.D.); (S.D.-D.); (V.M.S.)
| | - Valérie Pelletier
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologiques, Hopitaux Universitaires de Strasbourg, F-67000 Strasbourg, France; (V.P.); (H.D.)
| | - Béatrice Bocquet
- National Reference Centre for Inherited Sensory Diseases, University of Montpellier, Montpellier University Hospital, Sensgene Care Network, ERN-EYE Network, F-34000 Montpellier, France; (I.M.); (B.B.)
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, F-34000 Montpellier, France
| | - Margarita G. Todorova
- Department of Ophthalmology, Cantonal Hospital, 9007 St. Gallen, Switzerland;
- Department of Ophthalmology, University of Zürich, 8091 Zürich, Switzerland
- Department of Ophthalmology, University of Basel, 4056 Basel, Switzerland
| | - Anne-Gaëlle Le Moing
- Department of Child Neurology, Amiens-Picardy University Hospital, F-80000 Amiens, France;
| | - Aurore Devos
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, F-59000 Lille, France; (A.F.P.); (O.G.); (A.D.)
| | - Daniel F. Schorderet
- Faculty of Biology and Medicine, University of Lausanne and Faculty of Life Sciences, Ecole Polytechnique Fédérale of Lausanne, 1004 Lausanne, Switzerland;
| | - Florence Jobic
- Unité de Génétique Médicale et Oncogénétique, Centre Hospitalier Universitaire Amiens Picardie, F-80000 Amiens, France;
| | - Sabine Defoort-Dhellemmes
- Exploration de la Vision et Neuro-Ophtalmology, CHU de Lille, F-59000 Lille, France; (I.D.); (S.D.-D.); (V.M.S.)
| | - Hélène Dollfus
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologiques, Hopitaux Universitaires de Strasbourg, F-67000 Strasbourg, France; (V.P.); (H.D.)
| | - Vasily M. Smirnov
- Exploration de la Vision et Neuro-Ophtalmology, CHU de Lille, F-59000 Lille, France; (I.D.); (S.D.-D.); (V.M.S.)
- Université de Lille, Faculté de Médecine, F-59000 Lille, France
| | - Claire-Marie Dhaenens
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, F-59000 Lille, France; (A.F.P.); (O.G.); (A.D.)
- Correspondence: ; Tel.: +33-320444953
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A Novel, Apparently Silent Variant in MFSD8 Causes Neuronal Ceroid Lipofuscinosis with Marked Intrafamilial Variability. Int J Mol Sci 2022; 23:ijms23042271. [PMID: 35216386 PMCID: PMC8877174 DOI: 10.3390/ijms23042271] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/09/2022] [Accepted: 02/16/2022] [Indexed: 02/06/2023] Open
Abstract
Variants in MFSD8 can cause neuronal ceroid lipofuscinoses (NCLs) as well as nonsyndromic retinopathy. The mutation spectrum includes mainly missense and stop variants, but splice sites and frameshift variants have also been reported. To date, apparently synonymous substitutions have not been shown to cause MFSD8-associated diseases. We report two closely related subjects from a consanguineous Turkish family who presented classical features of NCLs but demonstrated marked intrafamilial variability in age at the onset and severity of symptoms. In fact, the difference in the onset of first neurologic symptoms was 15 years and that of ophthalmologic symptoms was 12 years. One subject presented an intellectual disability and a considerable cerebellar ataxia syndrome, while the other subject showed no intellectual disability and only a mild atactic syndrome. The diagnostic genetic testing of both subjects based on genome sequencing prioritized a novel, apparently synonymous variant in MFSD8, which was found in homozygosity in both subjects. The variant was not located within an integral part of the splice site consensus sequences. However, the bioinformatic analyses suggested that the mutant allele is more likely to cause exon skipping due to an altered ratio of exonic splice enhancer and silencer motifs. Exon skipping was confirmed in vitro by minigene assays and in vivo by RNA analysis from patient lymphocytes. The mutant transcript is predicted to result in a frameshift and, if translated, in a truncated protein. Synonymous variants are often given a low priority in genetic diagnostics because of their expected lack of functional impact. This study highlights the importance of investigating the impact of synonymous variants on splicing.
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9
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Qiao Y, Gu Y, Cheng Y, Su Y, Lv N, Shang Q, Xing Q. Case Report: Novel MFSD8 Variants in a Chinese Family With Neuronal Ceroid Lipofuscinoses 7. Front Genet 2022; 13:807515. [PMID: 35154277 PMCID: PMC8826235 DOI: 10.3389/fgene.2022.807515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/06/2022] [Indexed: 11/24/2022] Open
Abstract
Neuronal ceroid lipofuscinoses (NCLs) are among the most common progressive encephalopathies of childhood. Neuronal ceroid lipofuscinosis 7 (CLN7), one of the late infantile-onset NCLs, is an autosomal recessive disorder caused by mutations in the MFSD8 gene on chromosome 4q28. Almost all reported mutations of MFSD8 in CLN7 patients were SNVs. However, we report a 4-year-old boy with CLN7 harboring compound heterozygous mutations in the MFSD8 gene, including one novel two-nucleotide deletion c.136_137delAT (p. M46Vfs*22) and one whole gene deletion of MFSD8 confirmed by Sanger sequencing, genomic quantitative PCR and CNV-seq. Therefore, for nonconsanguineous CLN7 patients with homozygous mutations in the MFSD8 gene, genetic counseling staff should focus on the possibility of whole gene deletion. This is one case report describing a whole gene deletion in a Chinese patient with CLN7, suggesting the diagnosis of CLN7 should be based on clinical suspicion and genetic testing.
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Affiliation(s)
- Yimeng Qiao
- Institutes of Biomedical Sciences and Children's Hospital, Fudan University, Shanghai, China
| | - Yang Gu
- Children's Hospital of Zhengzhou University and Henan Children's Hospital, Zhengzhou, China
| | - Ye Cheng
- Institutes of Biomedical Sciences and Children's Hospital, Fudan University, Shanghai, China
| | - Yu Su
- Institutes of Biomedical Sciences and Children's Hospital, Fudan University, Shanghai, China
| | - Nan Lv
- Children's Hospital of Zhengzhou University and Henan Children's Hospital, Zhengzhou, China
| | - Qing Shang
- Children's Hospital of Zhengzhou University and Henan Children's Hospital, Zhengzhou, China
| | - Qinghe Xing
- Institutes of Biomedical Sciences and Children's Hospital, Fudan University, Shanghai, China.,Shanghai Center for Women and Children's Health, Shanghai, China
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10
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Wang Y, Teng Y, Liang D, Li Z, Wu L. Simultaneous Identification of Both MFSD8 and RDH12 Pathogenic Variants in a Chinese Family Affected With Retinitis Pigmentosa. Front Genet 2021; 12:715100. [PMID: 34567070 PMCID: PMC8458757 DOI: 10.3389/fgene.2021.715100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/16/2021] [Indexed: 11/13/2022] Open
Abstract
Retinitis pigmentosa (RP) is characterized by tremendous genetic and phenotypic heterogeneity. Here, we investigate the pathogeny of RP in a family to provide evidence for genetic and reproductive counseling for families. Although this pregnant woman of 8+3 weeks presented with RP, her first baby was born with RP, epilepsy, and cerebellar atrophy. The research identified a compound heterozygous mutation (c.998+3_998+6del/deletion) in the MFSD8 gene of the first born, explaining the cause of the proband’s disease, which cannot explain the mother’s. Then, a homozygous mutation c.343+1G > A in RDH12 of the mother was found. RT-PCR is employed to find that there is a skipping of exon 10 in MFSD8 and a 15-nucleotide retention of intron5 in RDH12. The coexistence of two independent instances of RP caused by distinct genes in one pedigree is demonstrated. Based on the diagnosis, a prenatal diagnosis performed on the fetus found that the fetus’s MFSD8 is affected by the same mutation as the proband. The research underscoring the complexity of RP and the need for the combination of extensive molecular genetic testing and clinical characterization in addition expands the spectrum of MFSD8 mutations. Finally, it is expected that the family members would be prevented from reproducing children with the similar disease.
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Affiliation(s)
- Yihui Wang
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics & Hunan Key Laboratory of Animal Models for Human Diseases, School of Life Sciences, Central South University, Changsha, China
| | - Yanling Teng
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics & Hunan Key Laboratory of Animal Models for Human Diseases, School of Life Sciences, Central South University, Changsha, China
| | - Desheng Liang
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics & Hunan Key Laboratory of Animal Models for Human Diseases, School of Life Sciences, Central South University, Changsha, China.,Hunan Jiahui Genetics Hospital, Changsha, China
| | - Zhuo Li
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics & Hunan Key Laboratory of Animal Models for Human Diseases, School of Life Sciences, Central South University, Changsha, China
| | - Lingqian Wu
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics & Hunan Key Laboratory of Animal Models for Human Diseases, School of Life Sciences, Central South University, Changsha, China.,Hunan Jiahui Genetics Hospital, Changsha, China
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11
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Huang B, Li X. The Role of Mfsd2a in Nervous System Diseases. Front Neurosci 2021; 15:730534. [PMID: 34566571 PMCID: PMC8461068 DOI: 10.3389/fnins.2021.730534] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 08/26/2021] [Indexed: 12/16/2022] Open
Abstract
Major facilitator superfamily (MFS) is the maximum and most diversified membrane transporter, acting as uniporters, symporters and antiporters. MFS is considered to have a good development potential in the transport of drugs for the treatment of brain diseases. The major facilitator superfamily domain containing protein 2a (Mfsd2a) is a member of MFS. Mfsd2a-knockout mice have shown a marked decrease of docosahexaenoic acid (DHA) level in brain, exhibiting neuron loss, microcephaly and cognitive deficits, as DHA acts essentially in brain growth and integrity. Mfsd2a has attracted more and more attention in the study of nervous system diseases because of its critical role in maintaining the integrity of the blood-brain barrier (BBB) and transporting DHA, including inhibiting cell transport in central nervous system endothelial cells, alleviating BBB injury, avoiding BBB injury in cerebral hemorrhage model, acting as a carrier etc. Up to now, the clinical research of Mfsd2a in nervous system diseases is rare. This article reviewed the current research progress of Mfsd2a in nervous system diseases. It summarized the physiological functions of Mfsd2a in the occurrence and development of intracranial hemorrhage (ICH), Alzheimer's disease (AD), sepsis-associated encephalopathy (SAE), autosomal recessive primary microcephaly (MCPH) and intracranial tumor, aiming to provide ideas for the basic research and clinical application of Mfsd2a.
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Affiliation(s)
- Bei Huang
- Operational Management Office, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Xihong Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
- Emergency Department, West China Second University Hospital, Sichuan University, Chengdu, China
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12
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Lo Faro V, Ten Brink JB, Snieder H, Jansonius NM, Bergen AA. Genome-wide CNV investigation suggests a role for cadherin, Wnt, and p53 pathways in primary open-angle glaucoma. BMC Genomics 2021; 22:590. [PMID: 34348663 PMCID: PMC8336345 DOI: 10.1186/s12864-021-07846-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/18/2021] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND To investigate whether copy number variations (CNVs) are implicated in molecular mechanisms underlying primary open-angle glaucoma (POAG), we used genotype data of POAG individuals and healthy controls from two case-control studies, AGS (n = 278) and GLGS-UGLI (n = 1292). PennCNV, QuantiSNP, and cnvPartition programs were used to detect CNV. Stringent quality controls at both sample and marker levels were applied. The identified CNVs were intersected in CNV region (CNVR). After, we performed burden analysis, CNV-genome-wide association analysis, gene set overrepresentation and pathway analysis. In addition, in human eye tissues we assessed the expression of the genes lying within significant CNVRs. RESULTS We reported a statistically significant greater burden of CNVs in POAG cases compared to controls (p-value = 0,007). In common between the two cohorts, CNV-association analysis identified statistically significant CNVRs associated with POAG that span 11 genes (APC, BRCA2, COL3A1, HLA-DRB1, HLA-DRB5, HLA-DRB6, MFSD8, NIPBL, SCN1A, SDHB, and ZDHHC11). Functional annotation and pathway analysis suggested the involvement of cadherin, Wnt signalling, and p53 pathways. CONCLUSIONS Our data suggest that CNVs may have a role in the susceptibility of POAG and they can reveal more information on the mechanism behind this disease. Additional genetic and functional studies are warranted to ascertain the contribution of CNVs in POAG.
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Affiliation(s)
- Valeria Lo Faro
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Departments of Clinical Genetics and Ophthalmology, Amsterdam University Medical Center (AMC), Location AMC K2-217
- AMC-UvA, P.O.Box 22700, 1100 DE, Amsterdam, The Netherlands
| | - Jacoline B Ten Brink
- Departments of Clinical Genetics and Ophthalmology, Amsterdam University Medical Center (AMC), Location AMC K2-217
- AMC-UvA, P.O.Box 22700, 1100 DE, Amsterdam, The Netherlands
| | - Harold Snieder
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Nomdo M Jansonius
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Arthur A Bergen
- Departments of Clinical Genetics and Ophthalmology, Amsterdam University Medical Center (AMC), Location AMC K2-217
- AMC-UvA, P.O.Box 22700, 1100 DE, Amsterdam, The Netherlands. .,Department of Ophthalmology, Amsterdam UMC, Location AMC, Amsterdam, The Netherlands. .,Netherlands Institute for Neuroscience (NIN-KNAW), Amsterdam, The Netherlands.
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Magliyah MS, Geuer S, Alsalamah AK, Lenzner S, Drasdo M, Schatz P. Association of the Recurrent Rare Variant c.415T>C p.Phe139Leu in CLN5 With a Recessively Inherited Macular Dystrophy. JAMA Ophthalmol 2021; 139:339-343. [PMID: 33507209 PMCID: PMC7844694 DOI: 10.1001/jamaophthalmol.2020.6085] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 11/10/2020] [Indexed: 01/10/2023]
Abstract
Importance Homozygous variants in the neuronal ceroid lipofuscinosis type 5 (CLN5) gene are associated with neuronal ceroid lipofuscinosis, a progressive neurologic disorder that leads to ataxia, seizures, and early death. The association between a homozygous variant in this gene and a macular dystrophy is described here. Objective To describe an autosomal recessive macular dystrophy associated with a recurrent variant in CLN5. Design, Setting, and Participants This cohort study took place at a national referral center and had a follow-up duration ranging between 1 and 5 years. All patients who were identified to carry a specific homozygous missense variant in CLN5, among more than 2000 patients who were diagnosed with or suspected to have retinal dystrophies, who did not carry this variant, were included. Data were collected between June 2014 and September 2020. Exposures All patients who were sampled for DNA analysis due to molecularly unconfirmed retinal dystrophy and who were subsequently identified to carry the homozygous missense variant c.415T>C (p.Phe139Leu) in CLN5 were included, while patients who did not carry the variant were excluded. Main Outcomes and Measures Retinal phenotype associated with this specific homozygous missense variant in CLN5. Results Seven affected patients (mean [SD] age, 43 [18] years; age range, 33-52 years; 5 male) carried the homozygous missense in CLN5. All patients were diagnosed as having a macular dystrophy. Four patients had mild electroretinographic alterations. All patients had hypoautofluorescent maculas with retinal thinning (central subfield thickness, 80 µm). Visual acuity ranged between 2/200 and 20/100. Neurologic symptoms were mild (dizziness) in 5 patients and absent in 2 patients. Neuroimaging demonstrated cerebellar atrophy and white matter lesions, respectively, in 2 patients. Conclusions and Relevance These results suggest that CLN5, similar to CLN7, may be associated with isolated macular dystrophy as well as neuronal ceroid lipofuscinosis. The variant c.415T>C p.Phe139Leu does not seem to be associated with any prominent neurologic disease at least until the fourth to sixth decades of life. These findings may imply a specific role of CLN5 in macular neurons. Additional study is suggested, such as molecular screening for this variant in cohorts of patients with undiagnosed macular dystrophies and biological studies of its molecular effects.
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Affiliation(s)
- Moustafa S. Magliyah
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Kingdom of Saudi Arabia
- Ophthalmology Department, Prince Mohammed Medical City, AlJouf, Saudi Arabia
| | - Sinje Geuer
- Human Genetics Bioscientia Ingelheim, Ingelheim am Rhein, Germany
| | - Abrar K. Alsalamah
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Kingdom of Saudi Arabia
| | - Steffen Lenzner
- Human Genetics Bioscientia Ingelheim, Ingelheim am Rhein, Germany
| | - Mojgan Drasdo
- Human Genetics Bioscientia Ingelheim, Ingelheim am Rhein, Germany
| | - Patrik Schatz
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Kingdom of Saudi Arabia
- Department of Ophthalmology, Clinical Sciences, Scane County University Hospital, University of Lund, Lund, Sweden
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Yuan S, Qi R, Fang X, Wang X, Zhou L, Sheng X. Two novel PDE6C gene mutations in Chinese family with achromatopsia. Ophthalmic Genet 2020; 41:591-598. [PMID: 32787476 DOI: 10.1080/13816810.2020.1802762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Background: Achromatopsia (ACHM) is an inherited retinal disease affecting the cone cell function. To date, six pathogenic genes of ACHM have been identified. However, the diagnostic and therapeutic methods of this disorder remain limited. Herein, to characterize the clinical features and genetic causes of three affected siblings in a Chinese family with ACHM, we used target next-generation sequencing (NGS) and found new pathogenic factors associated with ACHM in this family. Materials and methods: Three patients with ACHM and three healthy family members were included in this study. All participants received comprehensive ophthalmic tests. NGS approach was performed on the patients to determine the causative mutation for this family. The silico analysis was also applied to predict the pathogenesis of identified mutations. Results: Genetic assessments revealed compound heterozygous mutations of the PDE6C gene (c.1413 + 1 G > C, c.305 G > A), carried by all three patients. Both mutations were novel and predicted to be deleterious by six types of online predictive software. The heterozygous PDE6C missense mutation (c.305 G > A) was found from the mother and the heterozygous PDE6C splice site mutation (c.1413 + 1 G > C) was found in the father and all the children. All patients in the family showed typical signs and symptoms of ACHM. Conclusions: We report novel compound heterozygous PDE6C mutations in causing ACHM and further confirm the clinical diagnosis. Our study extends the genotypic spectrums for PDE6C-ACHM and better illustrates its genotype-phenotype correlations, which would help the ACHM patients with better genetic diagnosis, prognosis, and gene treatment.
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Affiliation(s)
- Shiqin Yuan
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
| | - Rui Qi
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China.,Aier Eye Hospital Group, Hubin Aier Eye Hospital , Binzhou, Shangdong, China
| | - Xinhe Fang
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
| | - Xiaoguang Wang
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
| | - Liang Zhou
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
| | - Xunlun Sheng
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
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Magliyah M, AlRaddadi O, Balbaid A, Schatz P. Multimodal retinal imaging in MFSD8-neuronal ceroid lipofuscinosis. Ophthalmic Genet 2020; 40:588-590. [PMID: 31909682 DOI: 10.1080/13816810.2019.1709125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Moustafa Magliyah
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.,Ophthalmology Department, Prince Mohammed Medical City, AlJouf, Saudi Arabia
| | - Osama AlRaddadi
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.,Ophthalmology Department, Ohud Hospital, Madinah, Saudi Arabia
| | - Abdullah Balbaid
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.,Retina Department, Jeddah Eye Hospital, Jeddah, Saudi Arabia
| | - Patrik Schatz
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.,Department of Ophthalmology, Clinical Sciences, Skane County University Hospital, Lund University, Lund, Sweden
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Guevar J, Hug P, Giebels F, Durand A, Jagannathan V, Leeb T. A major facilitator superfamily domain 8 frameshift variant in a cat with suspected neuronal ceroid lipofuscinosis. J Vet Intern Med 2019; 34:289-293. [PMID: 31860737 PMCID: PMC6979099 DOI: 10.1111/jvim.15663] [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: 09/09/2019] [Accepted: 10/30/2019] [Indexed: 11/29/2022] Open
Abstract
A 2‐year‐old male domestic shorthair cat was presented for a progressive history of abnormal posture, behavior, and mentation. Menace response was absent bilaterally, and generalized tremors were identified on neurological examination. A neuroanatomical diagnosis of diffuse brain dysfunction was made. A neurodegenerative disorder was suspected. Magnetic resonance imaging findings further supported the clinical suspicion. Whole‐genome sequencing of the affected cat with filtering of variants against a database of unaffected cats was performed. Candidate variants were confirmed by Sanger sequencing followed by genotyping of a control population. Two homozygous private (unique to individual or families and therefore absent from the breed‐matched controlled population) protein‐changing variants in the major facilitator superfamily domain 8 (MFSD8) gene, a known candidate gene for neuronal ceroid lipofuscinosis type 7 (CLN7), were identified. The affected cat was homozygous for the alternative allele at both variants. This is the first report of a pathogenic alteration of the MFSD8 gene in a cat strongly suspected to have CLN7.
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Affiliation(s)
- Julien Guevar
- Division of Clinical Neurology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Petra Hug
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Felix Giebels
- Division of Clinical Neurology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Alexane Durand
- Division of Clinical Radiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Vidhya Jagannathan
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Tosso Leeb
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland
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