TOR1A encodes torsinA, an ATP-dependent chaperone protein that functions in protein quality control and cellular trafficking. The protein localizes to the endoplasmic reticulum, where it facilitates clearance of misfolded proteins and assists in proper refolding of variants such as SGCE, and also regulates nuclear envelope integrity by linking the cytoskeleton to the nuclear lamina. TOR1A regulates subcellular localization of the dopamine transporter SLC6A3, thereby modulating dopaminergic neurotransmission in basal ganglia circuits, and controls synaptic vesicle recycling through regulation of STON2 stability. Heterozygous loss-of-function mutations in TOR1A cause DYT1 (dystonia 1, torsion, autosomal dominant), the most frequent genetic form of early-onset primary dystonia 1. A recurrent 3-bp GAG deletion, resulting in loss of a glutamic acid residue, is responsible for most cases of typical early limb-onset dystonia 2. TOR1A expression is highly enriched in substantia nigra dopamine neurons, implicating disrupted dopaminergic function in DYT1 pathophysiology 1. Recent evidence suggests tremor occurs in DYT-TOR1A with variable frequency 3, and endoplasmic reticulum stress response mechanisms have been linked to DYT1 pathogenesis 4. Biallelic variants in TOR1A cause autosomal-recessive arthrogryposis multiplex congenita 5 (AMC5), a severe neurodevelopmental disorder presenting with congenital contractures, developmental delay, and facial dysmorphism, with genotype-phenotype correlations predicting disease severity and survival 5. No approved therapeutics specifically targeting TOR1A dysfunction currently exist, though understanding shared dystonia pathways may facilitate future treatment development.