Authors: Kristoffer Haugarvoll Charalampos Tzoulis Gia T Tran Bjørn Karlsen Bernt A Engelsen Per M Knappskog Laurence A Bindoff
Publish Date: 2013/12/03
Volume: 261, Issue: 2, Pages: 358-362
Abstract
Seizures have been reported in two families with myoclonusdystonia due to epsilonsarcoglycan SGCE mutations We report a Norwegian family with myoclonusdystonia and epilepsy associated with a novel SGCE mutation All six manifesting SGCE mutation carriers had myoclonus and dystonia was present in two patients Sequencing of the SGCE gene in the proband identified a novel frameshift c372delG mutation that predicts the amino acid change pLys125SerfsX7 and the formation of a premature stop codon The mutation segregated with myoclonusdystonia in the family The typical motor symptoms were accompanied by generalized seizures in four of six affected mutation carriers The seizure type included febrile absence and generalized tonic–clonic seizures One deceased patient with severe epilepsy and myoclonus could not be tested for the SGCE mutation Seizures are rarely observed in myoclonusdystonia patients with SGCE mutations and may not be a part of the phenotype The cooccurrence of seizures and myoclonusdystonia suggests that they are both due to the same underlying SGCE mutation However with epilepsy being a relatively common disorder and lack of complete cosegregation in our and previous families it is possible that some patients suffer from two different genetic disorders The presence of seizures and EEG abnormalities should not be considered exclusion criteria for the diagnosis of myoclonusdystonia
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