TOR1A and Dystonia: In DYT1, mutant TOR1A interferes with the nucleocytoskeletal network, possibly by restricting movement of these particles/filaments, and hence this may affect development of neuronal pathways in the brain.40,41 Mutant TUBB4a could act through a similar pathway to TOR1A, with impaired tubulin autoregulation, which may result in a stoichiometric imbalance of α and β tubulin subunits and aberrant cytoskeletal binding.42 Further work on this interaction will be important to define the role of TUBB4a, the cytoskeleton, and the potential interactions with other dystonia disease genes.