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Nomenclature of Genetically Determined Myoclonus Syndromes : Recommendations of the International Parkinson and Movement Disorder Society Task Force

van der Veen, Sterre ; Zutt, Rodi ; Klein, Christine ; Marras, Connie ; Berkovic, Samuel F. ; Caviness, John N. ; Shibasaki, Hiroshi ; de Koning, Tom J. LU and Tijssen, Marina A.J. (2019) In Movement Disorders 34(11). p.1602-1613
Abstract

Genetically determined myoclonus disorders are a result of a large number of genes. They have wide clinical variation and no systematic nomenclature. With next-generation sequencing, genetic diagnostics require stringent criteria to associate genes and phenotype. To improve (future) classification and recognition of genetically determined movement disorders, the Movement Disorder Society Task Force for Nomenclature of Genetic Movement Disorders (2012) advocates and renews the naming system of locus symbols. Here, we propose a nomenclature for myoclonus syndromes and related disorders with myoclonic jerks (hyperekplexia and myoclonic epileptic encephalopathies) to guide clinicians in their diagnostic approach to patients with these... (More)

Genetically determined myoclonus disorders are a result of a large number of genes. They have wide clinical variation and no systematic nomenclature. With next-generation sequencing, genetic diagnostics require stringent criteria to associate genes and phenotype. To improve (future) classification and recognition of genetically determined movement disorders, the Movement Disorder Society Task Force for Nomenclature of Genetic Movement Disorders (2012) advocates and renews the naming system of locus symbols. Here, we propose a nomenclature for myoclonus syndromes and related disorders with myoclonic jerks (hyperekplexia and myoclonic epileptic encephalopathies) to guide clinicians in their diagnostic approach to patients with these disorders. Sixty-seven genes were included in the nomenclature. They were divided into 3 subgroups: prominent myoclonus syndromes, 35 genes; prominent myoclonus syndromes combined with another prominent movement disorder, 9 genes; disorders that present usually with other phenotypes but can manifest as a prominent myoclonus syndrome, 23 genes. An additional movement disorder is seen in nearly all myoclonus syndromes: ataxia (n = 41), ataxia and dystonia (n = 6), and dystonia (n = 5). However, no additional movement disorders were seen in related disorders. Cognitive decline and epilepsy are present in the vast majority. The anatomical origin of myoclonus is known in 64% of genetic disorders: cortical (n = 34), noncortical areas (n = 8), and both (n = 1). Cortical myoclonus is commonly seen in association with ataxia, and noncortical myoclonus is often seen with myoclonus-dystonia. This new nomenclature of myoclonus will guide diagnostic testing and phenotype classification.

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author
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publishing date
type
Contribution to journal
publication status
published
subject
keywords
genetics, hyperekplexia, myoclonic epilepsy, myoclonus, nomenclature
in
Movement Disorders
volume
34
issue
11
pages
12 pages
publisher
John Wiley and Sons Inc.
external identifiers
  • pmid:31584223
  • scopus:85073936091
ISSN
0885-3185
DOI
10.1002/mds.27828
language
English
LU publication?
no
id
eac86b88-65b1-4c5a-931f-da005183defc
date added to LUP
2020-01-28 09:48:01
date last changed
2020-10-27 03:43:59
@article{eac86b88-65b1-4c5a-931f-da005183defc,
  abstract     = {<p>Genetically determined myoclonus disorders are a result of a large number of genes. They have wide clinical variation and no systematic nomenclature. With next-generation sequencing, genetic diagnostics require stringent criteria to associate genes and phenotype. To improve (future) classification and recognition of genetically determined movement disorders, the Movement Disorder Society Task Force for Nomenclature of Genetic Movement Disorders (2012) advocates and renews the naming system of locus symbols. Here, we propose a nomenclature for myoclonus syndromes and related disorders with myoclonic jerks (hyperekplexia and myoclonic epileptic encephalopathies) to guide clinicians in their diagnostic approach to patients with these disorders. Sixty-seven genes were included in the nomenclature. They were divided into 3 subgroups: prominent myoclonus syndromes, 35 genes; prominent myoclonus syndromes combined with another prominent movement disorder, 9 genes; disorders that present usually with other phenotypes but can manifest as a prominent myoclonus syndrome, 23 genes. An additional movement disorder is seen in nearly all myoclonus syndromes: ataxia (n = 41), ataxia and dystonia (n = 6), and dystonia (n = 5). However, no additional movement disorders were seen in related disorders. Cognitive decline and epilepsy are present in the vast majority. The anatomical origin of myoclonus is known in 64% of genetic disorders: cortical (n = 34), noncortical areas (n = 8), and both (n = 1). Cortical myoclonus is commonly seen in association with ataxia, and noncortical myoclonus is often seen with myoclonus-dystonia. This new nomenclature of myoclonus will guide diagnostic testing and phenotype classification.</p>},
  author       = {van der Veen, Sterre and Zutt, Rodi and Klein, Christine and Marras, Connie and Berkovic, Samuel F. and Caviness, John N. and Shibasaki, Hiroshi and de Koning, Tom J. and Tijssen, Marina A.J.},
  issn         = {0885-3185},
  language     = {eng},
  month        = {11},
  number       = {11},
  pages        = {1602--1613},
  publisher    = {John Wiley and Sons Inc.},
  series       = {Movement Disorders},
  title        = {Nomenclature of Genetically Determined Myoclonus Syndromes : Recommendations of the International Parkinson and Movement Disorder Society Task Force},
  url          = {http://dx.doi.org/10.1002/mds.27828},
  doi          = {10.1002/mds.27828},
  volume       = {34},
  year         = {2019},
}