Gene TOR1A
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Also known as
Torsin 1A, DYT1, Dystonia 1, DQ2, Torsin AOverview
TOR1A (Torsin Family 1 Member A) encodes torsinA, an AAA+ ATPase protein located in the endoplasmic reticulum and nuclear envelope. TorsinA functions as a molecular chaperone involved in protein quality control and the maintenance of nuclear envelope integrity. The protein plays crucial roles in the processing and degradation of misfolded proteins, regulation of the LINC complex that connects the nucleoskeleton to the cytoskeleton, and proper localization of nuclear envelope proteins. TorsinA is particularly important in neurons, where it contributes to maintaining cellular homeostasis and protecting against protein aggregation and cellular stress.Mutations in TOR1A, most commonly a GAG deletion causing loss of a glutamic acid residue (deltaE302/303), cause DYT1 dystonia, also known as early-onset primary torsion dystonia. This is one of the most common forms of inherited dystonia, characterized by involuntary muscle contractions causing twisting movements and abnormal postures. DYT1 dystonia typically begins in childhood or adolescence, often initially affecting a limb before potentially generalizing. The condition is inherited in an autosomal dominant pattern with reduced penetrance (approximately 30-40%), meaning many mutation carriers remain asymptomatic. Treatment focuses on symptomatic management with medications, botulinum toxin injections, and in severe cases, deep brain stimulation. Genetic testing allows for diagnosis, family counseling, and informed reproductive decisions.