title: Dystonic tremor caused by mutation of the glucose transporter gene GLUT1.
abstract: Glucose transporter 1 deficiency syndrome (GLUT1-DS) is due to heterozygous mutation of the glucose transporter type 1 gene (GLUT1/SLC2A1). GLUT1-DS is characterized by movement disorders, including paroxysmal exercise-induced dystonia (PED), as well as seizures, mental retardation and hypoglycorrhachia. Tremor was recently shown to be part of the phenotype, but its clinical and electrophysiological features have not yet been described in detail, and GLUT1 tremor reports are rare. We describe two patients, a young woman and her mother, who were referred to us for tremor. We also systematically review published cases of GLUT1-DS with tremor (14 cases, including ours), focusing on clinical features. In most cases (10/14), the tremor, which involved the limbs and voice, fulfilled clinical criteria for dystonic tremor (DT), occurring in body areas affected by dystonia. Tremor was the only permanent symptom in 2 cases. Recordings, reported here for the first time, showed an irregular 6- to 8.5-Hz tremor compatible with DT in our two patients. These findings show that tremor, and particularly DT, may be a presenting symptom of GLUT1-DS. Patients who present with dystonic tremor, with or without mental retardation, seizures, movement disorders and/or a family history, should therefore be screened for GLUT1-DS.
authors.affiliation: AP-HP, Service de Neuropédiatrie, Hôpital Trousseau, Paris, France. an_schlum@yahoo.fr
authors.forename: Anne
authors.initials: A
authors.lastname: Roubergue
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Apartis
authors.forename: Valérie
authors.initials: V
authors.lastname: Mesnage
authors.forename: Diane
authors.initials: D
authors.lastname: Doummar
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Trocello
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Roze
authors.forename: Guillaume
authors.initials: G
authors.lastname: Taieb
authors.forename: Thierry Billette
authors.initials: TB
authors.lastname: De Villemeur
authors.forename: Sandrine
authors.initials: S
authors.lastname: Vuillaumier-Barrot
authors.forename: Marie
authors.initials: M
authors.lastname: Vidailhet
authors.forename: Richard
authors.initials: R
authors.lastname: Levy
mesh_terms: D000328:Adult; D020821:Dystonic Disorders / Q000235:genetics*; D004576:Electromyography / Q000379:methods; D004594:Electrophysiology / Q000379:methods; D005260:Female; D051272:Glucose Transporter Type 1 / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D010802:Phylogeny; D014202:Tremor / Q000235:genetics*
chemical_list: D051272:Glucose Transporter Type 1; C495677:SLC2A1 protein, human