A Novel Missense OPA1 Mutation in a Patient with Dominant Optic Atrophy and Cervical Dystonia

Dystonia, spastic tetraplegia, and ataxia due to a novel mutation in the dynamin domain of OPA1

Movement disorders manifest in various hereditary neurodegenerative diseases. We reported a young man who presented with progressive upper limb dystonia, spastic tetraplegia, and ataxia. Whole-exome sequencing (WES) revealed a novel variant, c.2357A > G, in the dynamin domain of OPA1. No mtDNA deletion was detected in muscle by long-range PCR. Atrophy and decreased glucose metabolism of the basal ganglia were discovered. Decreased mtDNA copy number, fragmented mitochondria, slightly impaired oxidative phosphorylation, and increased autophagy were detected in mutant fibroblasts. Evident oxidative phosphorylation impairment and mtDNA deletions were not involved in the pathogenicity of this mutation unlike mutations in the GTPase domain of OPA1.

Nomenclature of Genetic Movement Disorders: Recommendations of the International Parkinson and Movement Disorder Society Task Force - An Update

In 2016, the Movement Disorder Society Task Force for the Nomenclature of Genetic Movement Disorders presented a new system for naming genetically determined movement disorders and provided a criterion-based list of confirmed monogenic movement disorders. Since then, a substantial number of novel disease-causing genes have been described, which warrant classification using this system. In addition, with this update, we further refined the system and propose dissolving the imaging-based categories of Primary Familial Brain Calcification and Neurodegeneration with Brain Iron Accumulation and reclassifying these genetic conditions according to their predominant phenotype. We also introduce the novel category of Mixed Movement Disorders (MxMD), which includes conditions linked to multiple equally prominent movement disorder phenotypes. In this article, we present updated lists of newly confirmed monogenic causes of movement disorders. We found a total of 89 different newly identified genes that warrant a prefix based on our criteria; 6 genes for parkinsonism, 21 for dystonia, 38 for dominant and recessive ataxia, 5 for chorea, 7 for myoclonus, 13 for spastic paraplegia, 3 for paroxysmal movement disorders, and 6 for mixed movement disorder phenotypes; 10 genes were linked to combined phenotypes and have been assigned two new prefixes. The updated lists represent a resource for clinicians and researchers alike and they have also been published on the website of the Task Force for the Nomenclature of Genetic Movement Disorders on the homepage of the International Parkinson and Movement Disorder Society (https://www.movementdisorders.org/MDS/About/Committees--Other-Groups/MDS-Task-Forces/Task-Force-on-Nomenclature-in-Movement-Disorders.htm). © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson Movement Disorder Society.