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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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Brooks JK, Porter NC, Bisordi KA, Miclat CE, Greene CL. Review of general and head and neck/oral and maxillofacial features of Charcot-Marie-Tooth disease and dental management considerations. Oral Surg Oral Med Oral Pathol Oral Radiol 2022; 133:e170-e177. [PMID: 35305937 DOI: 10.1016/j.oooo.2021.12.125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 12/19/2021] [Indexed: 01/15/2023]
Abstract
Charcot-Marie-Tooth disease (CMTD) is an uncommon progressive neuromuscular disorder of the peripheral nervous system and primarily leads to distal extremity weakness and sensory deficits. Frequently, affected patients manifest pes cavus, drop foot, and digit contractures that may pose significant challenges in ambulation and grasping objects. Although there are numerous articles of this syndrome in the medical literature, there is a limited number of dental publications. The objective of this article is to review the general and head and neck/oral and maxillofacial features of CMTD. General guidelines for dental management are also provided.
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Affiliation(s)
- John K Brooks
- Clinical Professor, Department of Oncology and Diagnostic Sciences, University of Maryland School of Dentistry, Baltimore, MD, USA.
| | - Neil C Porter
- Assistant Professor, Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Katharine A Bisordi
- Instructor and Genetic Counselor, Department of Pediatrics, Division of Human Genetics, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Claire E Miclat
- Predoctoral student, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - Carol L Greene
- Professor, Director of Clinical Genetics Service, Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, USA
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Nan H, Hata T, Fukao T, Fukao T, Chen W, Kurita T, Natori T, Takiyama Y. MFN2-related Charcot-Marie-Tooth Disease with Atypical Ocular Manifestations. Intern Med 2021; 60:3969-3974. [PMID: 34121014 PMCID: PMC8758439 DOI: 10.2169/internalmedicine.7463-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We herein describe a Charcot-Marie-Tooth disease (CMT) family with a MFN2 mutation with atypical ocular manifestations. The proband, his mother, his third daughter, and his deceased maternal grandfather all had symptoms of CMT and a visual impairment (either cataracts or severe astigmatism). On whole-exome sequencing for the proband having CMT and congenital cataracts, we identified a c.314C>T (p.Thr105Met) mutation in MFN2, but no mutation in the causative genes associated with cataracts. This missense mutation in MFN2 co-segregated with CMT and the atypical ocular manifestations in this family. The findings of this study might help to expand the clinical phenotype of heterogeneous MFN2-related CMT.
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Affiliation(s)
- Haitian Nan
- Department of Neurology, University of Yamanashi, Japan
| | - Takanori Hata
- Department of Neurology, University of Yamanashi, Japan
| | - Toko Fukao
- Department of Neurology, University of Yamanashi, Japan
| | | | - Wanjing Chen
- Department of Ophthalmology, University of Yamanashi, Japan
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