Our purpose is to examine for evidence of genetic risk factors associated with idiopathic laryngeal motor control disorders. During the conception of the protocol, we were interested in investigating the pattern of inheritance of familial voice disorders, specifically spasmodic dysphonia and tremor. Interestingly, the initial search for families revealed several large families with idiopathic vocal fold paralysis with some family members experiencing symptoms of spasmodic dysphonia. During subsequent years, the research has focused on inherited forms of vocal fold paralysis in an attempt to determine the relationship between the laryngeal motor control disorder and other associated neuropathies, and to determine the existence of a specific genetic abnormality. These idiopathic laryngeal motor control disorders were one manifestation of peripheral neuropathies or may be an isolated disorder with only laryngeal involvement. Subsequently, we have shifted our emphasis back to the identification of genetic risk factors for spasmodic dysphonia.