title: Idiopathic cervical dystonia: Report of discordance in a pair of monozygotic twins.
abstract: The gene for idiopathic torsion dystonia (ITD) has been located on chromosome 9q32-34. It remains controversial whether cervical dystonia (CD) is genetically determined or not. A previous report of a concordant expression of CD in a pair of monozygotic twins suggested a genetic role. We report discordance in a pair of monozygotic twins, one presenting with adult-onset idiopathic CD with duration of disease for 7 yr, while the other co-twin remained normal. Family history was negative for dystonia. The pair of twins spent all their life in the same environment. This argues against the role of genetics in the etiology of CD.
authors.affiliation: Division of Neurology, Department of Medicine, Show-Chwan Memorial Hospital, Changhua, Taiwan.
authors.forename: J H
authors.initials: JH
authors.lastname: Chan
authors.forename: J K
authors.initials: JK
authors.lastname: Tsui