Primary (Idiopathic) Dystonia

In patients with primary dystonia, dystonia occurs as the only symptoms with the possible exception of tremor. The primary dystonias are frequently described as "pure dystonias." Primary dystonias were often referred to as "idiopathic torsion dystonia" or ITD, with the term "idiopathic" meaning "of unknown cause or etiology." However, because disease genes have been identified as an underlying cause, most experts now recommend using the term "primary." The word "torsion," which is still in use, refers to the twisting nature of the abnormal movement patterns seen in dystonia.

Primary dystonia may be familial or appear to occur in the absence of a family history (sporadic). The primary dystonias include several genetic disorders, some of which have been linked to changes (mutations) of specific genes mapped in some families to a particular chromosome. However, most primary dystonias are sporadic, have adult onset, and are focal or segmental in nature.

Certain primary dystonias have been mapped to particular genes. These include...

	Dystonias Caused by DYT1 Gene Mutation