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Elbert A, Dixon K, Shen Y, Hamilton S, Boerkoel CF, Jones SJ, Kanungo AK. Mitofusin 2 Variant Presenting With a Phenotype of Multiple System Atrophy of Cerebellar Subtype. Neurol Genet 2024; 10:e200114. [PMID: 38170145 PMCID: PMC10759145 DOI: 10.1212/nxg.0000000000200114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 11/01/2023] [Indexed: 01/05/2024]
Abstract
Objectives To investigate the etiology of cerebellar ataxia in an adult male patient. Methods We performed standard neurologic assessment and genome sequencing of a 62-year-old man with rapidly progressive balance and gait abnormalities. Results The propositus exhibited cognitive dysfunction, mild appendicular bradykinesia, prominent appendicular ataxia, dysarthria, and hypomimia with minimal dysautonomic symptoms. Nerve conduction studies showed mild peripheral sensory neuropathy and normal motor nerve conduction velocities. Brain imaging showed progressive cerebellar atrophy and gliosis of the olivopontocerebellar fibers, characterized by T2 hyperintensity within the pons. Genetic testing revealed a likely pathogenic germline variant in MFN2 (NM_014874: c.[838C>T];[=], p.(R280C)) in the GTPase domain (G) interface; pathogenic variants of MFN2 typically cause hereditary sensory and motor neuropathy VI or Charcot-Marie-Tooth disease 2A. The presence of progressive ataxia, "hot cross bun" sign, and dysautonomia has been associated with multiple system atrophy, cerebellar type (MSA-C). Discussion We describe progressive cerebellar ataxia in an individual with a deleterious variant in MFN2. Our findings suggest that pathogenic variants in MFN2 can result in a spectrum of phenotypes including cerebellar ataxia with cerebellar-pontine atrophy in the absence of significant neuropathy and in a manner closely resembling MSA-C.
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Affiliation(s)
- Adrienne Elbert
- From the Department of Medical Genetics (A.E., K.D., C.F.B., S.J.J.), University of British Columbia; Provincial Medical Genetics Program (A.E., S.H., C.B.), B.C. Women's Hospital and Health Centre; Canada's Michael Smith Genome Sciences Centre (K.D., Y.S., S.J.J.), BC Cancer; Fraser Health Movement Disorders Clinic (A.K.K.), Jim Pattison Outpatient Care and Surgery Centre, Surrey; and Department of Medicine (A.K.K.), Division of Neurology, University of British Columbia, Vancouver, Canada
| | - Katherine Dixon
- From the Department of Medical Genetics (A.E., K.D., C.F.B., S.J.J.), University of British Columbia; Provincial Medical Genetics Program (A.E., S.H., C.B.), B.C. Women's Hospital and Health Centre; Canada's Michael Smith Genome Sciences Centre (K.D., Y.S., S.J.J.), BC Cancer; Fraser Health Movement Disorders Clinic (A.K.K.), Jim Pattison Outpatient Care and Surgery Centre, Surrey; and Department of Medicine (A.K.K.), Division of Neurology, University of British Columbia, Vancouver, Canada
| | - Yaoqing Shen
- From the Department of Medical Genetics (A.E., K.D., C.F.B., S.J.J.), University of British Columbia; Provincial Medical Genetics Program (A.E., S.H., C.B.), B.C. Women's Hospital and Health Centre; Canada's Michael Smith Genome Sciences Centre (K.D., Y.S., S.J.J.), BC Cancer; Fraser Health Movement Disorders Clinic (A.K.K.), Jim Pattison Outpatient Care and Surgery Centre, Surrey; and Department of Medicine (A.K.K.), Division of Neurology, University of British Columbia, Vancouver, Canada
| | - Sara Hamilton
- From the Department of Medical Genetics (A.E., K.D., C.F.B., S.J.J.), University of British Columbia; Provincial Medical Genetics Program (A.E., S.H., C.B.), B.C. Women's Hospital and Health Centre; Canada's Michael Smith Genome Sciences Centre (K.D., Y.S., S.J.J.), BC Cancer; Fraser Health Movement Disorders Clinic (A.K.K.), Jim Pattison Outpatient Care and Surgery Centre, Surrey; and Department of Medicine (A.K.K.), Division of Neurology, University of British Columbia, Vancouver, Canada
| | - Cornelius F Boerkoel
- From the Department of Medical Genetics (A.E., K.D., C.F.B., S.J.J.), University of British Columbia; Provincial Medical Genetics Program (A.E., S.H., C.B.), B.C. Women's Hospital and Health Centre; Canada's Michael Smith Genome Sciences Centre (K.D., Y.S., S.J.J.), BC Cancer; Fraser Health Movement Disorders Clinic (A.K.K.), Jim Pattison Outpatient Care and Surgery Centre, Surrey; and Department of Medicine (A.K.K.), Division of Neurology, University of British Columbia, Vancouver, Canada
| | - Steven J Jones
- From the Department of Medical Genetics (A.E., K.D., C.F.B., S.J.J.), University of British Columbia; Provincial Medical Genetics Program (A.E., S.H., C.B.), B.C. Women's Hospital and Health Centre; Canada's Michael Smith Genome Sciences Centre (K.D., Y.S., S.J.J.), BC Cancer; Fraser Health Movement Disorders Clinic (A.K.K.), Jim Pattison Outpatient Care and Surgery Centre, Surrey; and Department of Medicine (A.K.K.), Division of Neurology, University of British Columbia, Vancouver, Canada
| | - Anish K Kanungo
- From the Department of Medical Genetics (A.E., K.D., C.F.B., S.J.J.), University of British Columbia; Provincial Medical Genetics Program (A.E., S.H., C.B.), B.C. Women's Hospital and Health Centre; Canada's Michael Smith Genome Sciences Centre (K.D., Y.S., S.J.J.), BC Cancer; Fraser Health Movement Disorders Clinic (A.K.K.), Jim Pattison Outpatient Care and Surgery Centre, Surrey; and Department of Medicine (A.K.K.), Division of Neurology, University of British Columbia, Vancouver, Canada
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Gallo S, Ory-Magne F, Le-Traon AP, Rascol O, Debs R, Leung C, Fabbri M. Clinical and imaging "red flags" for the diagnosis of multiple system atrophy lookalikes. Parkinsonism Relat Disord 2023:105372. [PMID: 36959044 DOI: 10.1016/j.parkreldis.2023.105372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/06/2023] [Accepted: 03/10/2023] [Indexed: 03/25/2023]
Affiliation(s)
- Silvia Gallo
- Department of Neurology, University Hospital of Toulouse, Toulouse, France; Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Fabienne Ory-Magne
- Department of Neurology, University Hospital of Toulouse, Toulouse, France
| | - Anne Pavy Le-Traon
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Olivier Rascol
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Rachel Debs
- Department of Neurology, University Hospital of Toulouse, Toulouse, France
| | - Clémence Leung
- Department of Neurology, University Hospital of Toulouse, Toulouse, France
| | - Margherita Fabbri
- Department of Neurology, University Hospital of Toulouse, Toulouse, France; French Reference Center for MSA, Centre d'Investigation Clinique de Toulouse CIC1436, Departments of Neurosciences and Clinical Pharmacology, NS-Park/FCRIN Network, NeuroToul COEN Center, University Hospital of Toulouse, INSERM, University of Toulouse 3, Toulouse, France.
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