A Novel Pattern of Dystonia in DYT-VPS16: "speaking in Tongues".

Objectives:To expand the phenotype and genotype of VPS16-related dystonia (DYT-VPS16). Methods:We report 2 patients with previously unreported VPS16 truncating variants and highlight some distinctive phenomenological characteristics of DYT-VPS16. Results:The 2 patients, who were unrelated, presented with early-onset orofacial dystonia with prominent tongue involvement. Case 1, a 37-year-old woman, developed disabling orofacial dystonia, with tongue protrusion (lingual dystonia), orofacial gesticulations, and hyperkinetic dysarthria, responsible for an odd "foreign language" quality. Case 2, a 36-year-old woman, exhibited orofacial dystonia with prominent lingual involvement and orofacial gesticulations. In both patients, orofacial dystonia led to predominant speech impairment with no or discrete swallowing difficulties. Discussion:Substantial tongue dystonia may be a distinctive feature of DYT-VPS16. Our cases widen the phenotypic spectrum of DYT-VPS16 and may provide physicians with a new clinical clue for this disease.