phs001733
Molecular Etiology of Early-Onset Dystonia
Primary torsin dystonias (PTD) are a group of movement disorders characterized by twisting muscle contractures, where dystonia is the only clinical sign (except for tremor) and there is no evidence of neuronal degeneration or an acquired cause. Eleven genes have been mapped for primary dystonia including DYT1 ( TOR1A), DYT2, DYT4 ( TUBB4A), DYT6 ( THAP1), DYT7, DYT13,, DYT17, DYT21, CIZ1, DYT24 ( ANO3), and DYT25 ( GNAL); however, only 3 genes ( TOR1A, THAP1, and GNAL) have mutations in early onset dystonia patients. Each is inherited as an autosomal dominant trait but with reduced penetrance, meaning that individuals can carry the mutation but do not show clinical symptoms.  The most common form of PTD is adult onset focal accounting for about 90% of all cases of dystonia with a prevalence estimated at 30/100,000 in the general population. A small percentage of focal cases are due to mutations in CIZ1, ANO3, THAP1, TUBB4A, and GNAL, but the vast majority... (for more see dbGaP study page.)