'North Sea' progressive myoclonus epilepsy: phenotype of subjects with GOSR2 mutation

Lomax, Lysa Boisse, Bayly, Marta A., Hjalgrim, Helle, Moller, Rikke S., Vlaar, Annemarie M., Aaberg, Kari M., Marquardt, Iris, Gandolfo, Luke C., Willemsen, Michel, Kamsteeg, Erik-Jan, O'Sullivan, John D., Korenke, G. Christoph, Bloem, Bastiaan R., de Coo, Irenaeus F., Verhagen, Judith M. A., Said, Ines, Prescott, Trine, Stray-Pedersen, Asbjorg, Rasmussen, Magnhild, Vears, Danya F., Lehesjoki, Anna-Elina, Corbett, Mark A., Bahlo, Melanie, Gecz, Jozef, Dibbens, Leanne M. and Berkovic, Samuel F. (2013) 'North Sea' progressive myoclonus epilepsy: phenotype of subjects with GOSR2 mutation. Brain, 136 4: 1146-1154. doi:10.1093/brain/awt021

Author Lomax, Lysa Boisse
Bayly, Marta A.
Hjalgrim, Helle
Moller, Rikke S.
Vlaar, Annemarie M.
Aaberg, Kari M.
Marquardt, Iris
Gandolfo, Luke C.
Willemsen, Michel
Kamsteeg, Erik-Jan
O'Sullivan, John D.
Korenke, G. Christoph
Bloem, Bastiaan R.
de Coo, Irenaeus F.
Verhagen, Judith M. A.
Said, Ines
Prescott, Trine
Stray-Pedersen, Asbjorg
Rasmussen, Magnhild
Vears, Danya F.
Lehesjoki, Anna-Elina
Corbett, Mark A.
Bahlo, Melanie
Gecz, Jozef
Dibbens, Leanne M.
Berkovic, Samuel F.
Title 'North Sea' progressive myoclonus epilepsy: phenotype of subjects with GOSR2 mutation
Formatted title
'North Sea' progressive myoclonus epilepsy: phenotype of subjects with GOSR2 mutation
Journal name Brain   Check publisher's open access policy
ISSN 0006-8950
Publication date 2013-04
Year available 2013
Sub-type Article (original research)
DOI 10.1093/brain/awt021
Volume 136
Issue 4
Start page 1146
End page 1154
Total pages 9
Place of publication Oxford, United Kingdom
Publisher Oxford University Press
Collection year 2014
Language eng
Formatted abstract
We previously identified a homozygous mutation in the Golgi SNAP receptor complex 2 gene (GOSR2) in six patients with progressive myoclonus epilepsy. To define the syndrome better we analysed the clinical and electrophysiological phenotype in 12 patients with GOSR2 mutations, including six new unrelated subjects. Clinical presentation was remarkably similar with early onset ataxia (average 2 years of age), followed by myoclonic seizures at the average age of 6.5 years. Patients developed multiple seizure types, including generalized tonic clonic seizures, absence seizures and drop attacks. All patients developed scoliosis by adolescence, making this an important diagnostic clue. Additional skeletal deformities were present, including pes cavus in four patients and syndactyly in two patients. All patients had elevated serum creatine kinase levels (median 734 IU) in the context of normal muscle biopsies. Electroencephalography revealed pronounced generalized spike and wave discharges with a posterior predominance and photosensitivity in all patients, with focal EEG features seen in seven patients. The disease course showed a relentless decline; patients uniformly became wheelchair bound (mean age 13 years) and four had died during their third or early fourth decade. All 12 cases had the same variant (c.430G>T, G144W) and haplotype analyses confirmed a founder effect. The cases all came from countries bounding the North Sea, extending to the coastal region of Northern Norway. ‘North Sea’ progressive myoclonus epilepsy has a homogeneous clinical presentation and relentless disease course allowing ready identification from the other progressive myoclonus epilepsies.
Keyword Progressive myoclonus epilepsy
Creatine kinase
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2014 Collection
School of Medicine Publications
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Citation counts: TR Web of Science Citation Count  Cited 10 times in Thomson Reuters Web of Science Article | Citations
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