Objective: To describe a case of a patient with a progressive primary isolated generalized dystonia of childhood onset associated to a novel SLC2A1 mutation with a favorable response to bilateral pallidal deep brain stimulation (GPi-DBS).

Background: : Glucose transporter type 1 facilitate the transports of the glucose across the blood brain barrier and astrocyte plasma. This transporter is primarily expressed in endothelial cells forming the blood brain barrier and in astrocytes (1). Glucose transporter type deficiency syndrome (Glut1-DS) is a neurometabolic disorder caused by mutations of the SLC2A1 gene, and is considered to be a rare disorder, estimates suggest that it accounts for approximately 1% (1% of what????). (2) Though mostly de novo, mutations of SLC2A1 gene have also been reported with an autosomal dominant mode of inheritance in rare families and may present considerable phenotypic variability that include classic and non-classic phenotypes.

Method: We present the case of a 21-year-old  Mexican woman who presented with  a primary isolated progressive generalized dystonia with onset at age 10. Family history was consistent with a similar phenotype in three different generations in her mother’s lineage. The dystonia syndrome was characterized by the progressive onset of orofacial dystonia, prominent laterocollis, torticollis and anterocaput, as well as trunk and limb dystonia and writer’s cramp. Her treatment included high doses of benzodiazepines, trihexiphenydil and botulinum toxin with poor to moderate response. Her UDRS (United Dystonia Rating Scale) score was 50 and her Fahn Marsden score was 19.5. Genetic testing for primary autosomal dystonias was negative (DYT-TOR1A, DYT-HPCA, DYT-GCH1, DYT6-THAP1, DYT-SCGE), but a heterozygous pathogenic SLC2A1 mutation was found, as cause of glucose transporter type 1 deficiency syndrome (GLUT1-DS).

Results: Clinical evaluation three months after surgery showed profound motor and quality of life outcomes as measured by UDRS (with a new score of 20).

Conclusion: The phenotypic spectrum of GLUT1-DS is broad, among these, uncommonly described is generalized dystonia.  In summary only one case reported in the literature similar to ours found. A patient that was treated with DBS-GPi for generalized dystonia with a good outcome. This report lends further support to the relevance of molecular genetic testing of patients with generalized dystonia in attempt to stratify DBS outcomes.

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MDS Abstracts - https://www.mdsabstracts.org/abstract/glut1-deficiency-syndrome-with-novel-mutation-responsive-to-gpi-dbs/