Dystonia-Causing Mutations as a Contribution to the Etiology of Spasmodic Dysphonia

ObjectiveSpasmodic dysphonia is a focal dystonia of the larynx with heterogeneous manifestations and association with familial risk factors. There are scarce data to allow precise understanding of etiology and pathophysiology. Screening for dystonia-causing genetic mutations has the potential to allow accurate diagnosis, inform about genotype-phenotype correlations, and allow a better understanding of mechanisms of disease.Study DesignCross-sectional study.SettingTertiary academic medical center.Subjects and MethodsWe enrolled patients presenting with spasmodic dysphonia to the voice clinic of our academic medical center. Data included demographics, clinical features, family history, and treatments administered. The following genes with disease-causing mutations previously associated with spasmodic dysphonia were screened: TOR1A (DYT1), TUBB4 (DYT4), and THAP1 (DYT6).ResultsEighty-six patients were recruited, comprising 77% females and 23% males. A definite family history of neurologic disorder was presen...